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• Resizing a LUKS encrypted volume

  - by mgorven

  I have a 500GiB ext4 filesystem on top of LUKS on top of an LVM LV. I want to resize the LV to 100GiB. I know how to resize ext4 on top of an LVM LV, but how do I deal with the LUKS volume? mgorven@moab:~% sudo lvdisplay /dev/moab/backup --- Logical volume --- LV Name /dev/moab/backup VG Name moab LV UUID nQ3z1J-Pemd-uTEB-fazN-yEux-nOxP-QQair5 LV Write Access read/write LV Status available # open 1 LV Size 500.00 GiB Current LE 128000 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 2048 Block device 252:3 mgorven@moab:~% sudo cryptsetup status backup /dev/mapper/backup is active and is in use. type: LUKS1 cipher: aes-cbc-essiv:sha256 keysize: 256 bits device: /dev/mapper/moab-backup offset: 3072 sectors size: 1048572928 sectors mode: read/write mgorven@moab:~% sudo tune2fs -l /dev/mapper/backup tune2fs 1.42 (29-Nov-2011) Filesystem volume name: backup Last mounted on: /srv/backup Filesystem UUID: 63877e0e-0549-4c73-8535-b7a81eb363ed Filesystem magic number: 0xEF53 Filesystem revision #: 1 (dynamic) Filesystem features: has_journal ext_attr resize_inode dir_index filetype extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize Filesystem flags: signed_directory_hash Default mount options: (none) Filesystem state: clean with errors Errors behavior: Continue Filesystem OS type: Linux Inode count: 32768000 Block count: 131071616 Reserved block count: 0 Free blocks: 112894078 Free inodes: 32044830 First block: 0 Block size: 4096 Fragment size: 4096 Reserved GDT blocks: 992 Blocks per group: 32768 Fragments per group: 32768 Inodes per group: 8192 Inode blocks per group: 512 RAID stride: 128 RAID stripe width: 128 Flex block group size: 16 Filesystem created: Sun Mar 11 19:24:53 2012 Last mount time: Sat May 19 13:29:27 2012 Last write time: Fri Jun 1 11:07:22 2012 Mount count: 0 Maximum mount count: 100 Last checked: Fri Jun 1 11:03:50 2012 Check interval: 31104000 (12 months) Next check after: Mon May 27 11:03:50 2013 Lifetime writes: 118 GB Reserved blocks uid: 0 (user root) Reserved blocks gid: 0 (group root) First inode: 11 Inode size: 256 Required extra isize: 28 Desired extra isize: 28 Journal inode: 8 Default directory hash: half_md4 Directory Hash Seed: 383bcbc5-fde9-4720-b98e-2d6224713ecf Journal backup: inode blocks

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• ZFS: Mirror vs. RAID-Z

  - by John Clayton

  I'm planning on building a file server using OpenSolaris and ZFS that will provide two primary services - be an iSCSI target for XenServer virtual machines & be a general home file server. The hardware I'm looking at includes 2x 4-port SATA controllers, 2x small boot drives (one on each controller), and 4x big drives for storage. This allows one free port per controller for upgrading the array down the road. Where I'm a little confused is how to setup the storage drives. For performance, mirroring appears to be king. I'm having a hard time seeing what the benefit would be of using RAIDZ over mirroring would be. With this setup I can see two options - two mirrored pools in one stripe, or RAIDZ2. Both should protect against 2 drive failures, and/or one controller failure...the only benefit of RAIDZ2 would be that any 2 drives could fail. The storage should be 50% of capacity in both cases, but the first should have much better performance, right? The other thing I'm trying to wrap my mind around is the benefit of mirrored arrays with more than two devices. For data integrity what, if any, would be the benefit of a RAIDZ over a three-way mirror? Since ZFS maintains file integrity what does RAIDZ bring to the table...doesn't ZFS's integrity checks negate the value of RAIDZ's parity?

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• ESX 4.0 space: DASD, NAS, or ?

  - by thormj

  I put together an ESX box for better management, but its performance is a WTF item; I'm a noob at dealing with ESX, so I'm looking for a laundry-list of reading material to help me straighten this out so I can go back to .NET programming. Current storage system: We're running Raid5+Hotspare (8x500 GB spindles) on a PERC6i on a Dell 2910. Due to ESX limitatios, the PERC is showing the storage as 1x2TB + 1x800GB "partitions." I'm not sure of the setup's configuration (stride / stripe / ???) at all. Our Applications We have a SBS server as well as a minor (2x50 GB, but growing at 10GB/month) database server... Our application that lives on the database VM is CPU and I/O insense; it's a database churning excercise mixed in with a lot of computation on the data (fixing that performance is what I'm supposed to be working on)... Perfomance Issue When I do a backup, restore, or worse (copy a backup from 1 vm to another to move it to the QA VM), the entire system slows to a crawl (even "unrelated" VMs). I originally thought a DASD situation would be quite good since you had PCI-x bandwidth, but the systemwide slowdown is killing productivity. Questions What should I do to make an intelligent decision about NAS vs RAID vs SAN vs DASD? Are there sweet spots/ugly spots in the storage setup? Can you use a SSD PCI-X card in ESX for the tempdb? Good/Bad idea? Is there any way to "share" some image in a copy-on-write fashion? Most of the "Backup-Copy-Restore" is to "put a clean image on the dev boxes"; if I could have them "share" the master image, the "big copy" (2x50 GB) would only need to be done once per week instead of once per dev per week...[runtime performance isn't a concern with the dev boxes, but the backup/copy/restore kills production, SBS, and everything else on the box]

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• How can I recover my system after running 'mkfs' on the system partition?

  - by Filip Podgórny

  I am not a Linux user, and was doing some homework, I blindly typed sudo mkfs ext3 dev/sda2 (I had Ubuntu as Windows installation). I've done few more things, and turned Ubuntu off to switch on Windows back. No operating system installed - this is the message I'm getting. I plugged my HDD onto another computer and all my files are still there. What should I do to get my windows installation back? df -l (before mkfs) /dev/loop0 29G 2,0G 27G 8% / udev 3,0G 4,0K 3,0G 1% /dev tmpfs 1,2G 900K 1,2G 1% /run none 5,0M 0 5,0M 0% /run/lock none 3,0G 1,3M 3,0G 1% /run/shm /dev/sda3 455G 123G 333G 27% /host /dev/sdb1 1,9G 820M 1,1G 43% /media/PHONE CARD mkfs output (polish, sorry) mke2fs 1.41.14 (22-Dec-2010) Etykieta systemu plików= Typ OS: Linux Rozmiar bloku=1024 (log=0) Rozmiar fragmentu=1024 (log=0) Stride=0 bloków, szerokosc Stripe=0 bloków 25688 i-wezlów, 102400 bloków 5120 bloków (5.00%) zarezerwowanych dla superuzytkownika Pierwszy blok danych=1 Maksymalna liczba bloków systemu plików=67371008 13 grup bloków 8192 bloków w grupie, 8192 fragmentów w grupie 1976 i-wezlów w grupie Kopie zapasowe superbloku zapisane w blokach: 8193, 24577, 40961, 57345, 73729 Zapis tablicy i-wezlów: zakonczono Tworzenie kroniki (4096 bloków): wykonano Zapis superbloków i podsumowania systemu plików: wykonano Ten system plików bedzie automatycznie sprawdzany co kazde 30 montowan lub co 180 dni, zaleznie co nastapi pierwsze. Mozna to zmienic poprzez tune2fs -c lub -i.

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• How do I make wallpaper fit both monitors in dual monitor setup?

  - by Ben

  I am deploying some custom corporate wallpaper as part of a Windows 7 rollout. Some people will be using dual monitors, and the additional monitors may be either 4:3 or widescreen. I want to use the same wallpaper on both screens (i.e. 2 copies of the same wallpaper, not stretched across both.) If I set the background to "stretch", it uses the aspect ratio of the primary monitor to stretch the wallpaper on both monitors. So, for example, if I have a dual monitor setup using a 4:3 TFT as primary and my (widescreen) laptop LCD as secondary - the image shows on the laptop LCD in 4:3, with a black stripe down either side. I've only noticed this as an issue with my "custom" wallpaper. Both the default MS wallpaper and the built in Lenovo wallpaper don't seem to have this issue. Is this by using "trickery" such as using an image larger than the largest resolution you will have and centering it? (i.e. so you crop out part of the image.) Or can this be done "properly"? I don't want to use 3rd party software to do this, but would happily do a bit of Powershell scripting if this would solve the issue. Thanks in advance, Ben

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• mkfs Operation Takes Very Long on Linux Software Raid 5

  - by Elmar Weber

  I've set-up a Linux software raid level 5 consisting of 4 * 2 TB disks. The disk array was created with a 64k stripe size and no other configuration parameters. After the initial rebuild I tried to create a filesystem and this step takes very long (about half an hour or more). I tried to create an xfs and ext3 filesystem, both took a long time, with mkfs.ext3 I observed the following behaviour, which might be helpful: writing inode tables runs fast until it reaches 1053 (~ 1 second), then it writes about 50, waits for two seconds, then the next 50 are written (according to the console display) when I try to cancel the operation with Control+C it hangs for half a minute before it is really canceled The performance of the disks individually is very good, I've run bonnie++ on each one separately with write / read values of around 95 / 110MB/s. Even when I run bonnie++ on every drive in parallel the values are only reduced by about 10 MB. So I'm excluding hardware / I/O scheduling in general as a problem source. I tried different configuration parameters for stripe_cache_size and readahead size without success, but I don't think they are that relevant for the file system creation operation. The server details: Linux server 2.6.35-27-generic #48-Ubuntu SMP x86_64 GNU/Linux mdadm - v2.6.7.1 Does anyone has a suggestion on how to further debug this?

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• Flash drive suddenly died. Why? Can I recover it?

  - by mg

  Hi, I have a flash drive that I used not too much but, after few month of inactivity, it died. I know that flash drives have a limited write cycles but I am sure that this is not the problem. I tried to create a new partition table and format the drive nothing worked. This is the output of mkfs.ext2. marco@pinguina:~$ sudo LANG=en.UTF-8 mkfs.ext2 -v -c /dev/sdc1 [sudo] password for marco: mke2fs 1.41.11 (14-Mar-2010) fs_types for mke2fs.conf resolution: 'ext2', 'default' Calling BLKDISCARD from 0 to 4001431552 failed. Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) Stride=0 blocks, Stripe width=0 blocks 244320 inodes, 976912 blocks 48845 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=1002438656 30 block groups 32768 blocks per group, 32768 fragments per group 8144 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736 Running command: badblocks -b 4096 -X -s /dev/sdc1 976911 badblocks: Input/output error during ext2fs_sync_device Checking for bad blocks (read-only test): done Block 0 in primary superblock/group descriptor area bad. Blocks 0 through 2 must be good in order to build a filesystem. Aborting.... Is there something I can do to recover it?

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• mkfs Operation Takes Very Long on Linux Software Raid 5

  - by Elmar Weber

  I've set-up a Linux software raid level 5 consisting of 4 * 2 TB disks. The disk array was created with a 64k stripe size and no other configuration parameters. After the initial rebuild I tried to create a filesystem and this step takes very long (about half an hour or more). I tried to create an xfs and ext3 filesystem, both took a long time, with mkfs.ext3 I observed the following behaviour, which might be helpful: writing inode tables runs fast until it reaches 1053 (~ 1 second), then it writes about 50, waits for two seconds, then the next 50 are written (according to the console display) when I try to cancel the operation with Control+C it hangs for half a minute before it is really canceled The performance of the disks individually is very good, I've run bonnie++ on each one separately with write / read values of around 95 / 110MB/s. Even when I run bonnie++ on every drive in parallel the values are only reduced by about 10 MB. So I'm excluding hardware / I/O scheduling in general as a problem source. I tried different configuration parameters for stripe_cache_size and readahead size without success, but I don't think they are that relevant for the file system creation operation. The server details: Linux server 2.6.35-27-generic #48-Ubuntu SMP x86_64 GNU/Linux mdadm - v2.6.7.1 Does anyone has a suggestion on how to further debug this?

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• Should I use "Raid 5 + spare" or "Raid 6"?

  - by Trevor Boyd Smith

  What is "Raid 5 + Spare" (excerpt from User Manual, Sect 4.17.2, P.54): RAID5+Spare: RAID 5+Spare is a RAID 5 array in which one disk is used as spare to rebuild the system as soon as a disk fails (Fig. 79). At least four disks are required. If one physical disk fails, the data remains available because it is read from the parity blocks. Data from a failed disk is rebuilt onto the hot spare disk. When a failed disk is replaced, the replacement becomes the new hot spare. No data is lost in the case of a single disk failure, but if a second disk fails before the system can rebuild data to the hot spare, all data in the array will be lost. What is "Raid 6" (excerpt from User Manual, Sect 4.17.2, P.54): RAID6: In RAID 6, data is striped across all disks (minimum of four) and a two parity blocks for each data block (p and q in Fig. 80) is written on the same stripe. If one physical disk fails, the data from the failed disk can be rebuilt onto a replacement disk. This Raid mode can support up to two disk failures with no data loss. RAID 6 provides for faster rebuilding of data from a failed disk. Both "Raid 5 + spare" and "Raid 6" are SO similar ... I can't tell the difference. When would "Raid 5 + Spare" be optimal? And when would "Raid 6" be optimal"? The manual dumbs down the different raid with 5 star ratings. "Raid 5 + Spare" only gets 4 stars but "Raid 6" gets 5 stars. If I were to blindly trust the manual I would conclude that "Raid 6" is always better. Is "Raid 6" always better?

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• Array on servers which receive several hundred GB of data a day

  - by Matthew

  This is hopefully a simple question. Right now we are deploying servers which will serve as data warehouses. I know with raid 5 the best practice is 6 disks per raid 5. However, our plan is to use RAID 10 (both for performance and safety). We have a total of 14 disks (16 actually, but two are being used for OS). Keeping in mind that performance is very much an issue, which is better - doing several raid 1's? Do one large raid 10? One large raid 10 had been our original plan, but I want to see if anyone has any opinions I haven't thought of. Please note: This system was designed for using Raid 1+0, so losing half of the raw storage capacity is not an issue. Sorry i hadn't mentioned that initially. The concern is more whether or not we want to use one large Raid 1+0 containing all 14 disks, or several smaller raid 1+0's and then stripe across them using LVM. I know the best practice for higher raid levels is to never use more than 6 disks in an array.

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• How to display/define Mirror/Stripping pairs with mdadm

  - by Chris

  I want to make a standard linux software Raid10 over 4 HDD. The server has 4HDDs, 2 pairs from different vendors in order to avoid batch problems. I want to have the mirror over two different Vendors, and then the Stripe over the mirror pairs. I could do that by manually creating Raid1/0, but mdadm supports Raid level 10. I just cant figure out how the Raid10 is then handled and how the data is distributed. mdadm --detail /dev/md10 /dev/md10: Version : 1.2 Creation Time : Wed May 28 11:06:23 2014 Raid Level : raid10 Array Size : 1953260544 (1862.77 GiB 2000.14 GB) Used Dev Size : 976630272 (931.39 GiB 1000.07 GB) Raid Devices : 4 Total Devices : 4 Persistence : Superblock is persistent Update Time : Wed May 28 11:06:23 2014 State : clean, resyncing (PENDING) Active Devices : 4 Working Devices : 4 Failed Devices : 0 Spare Devices : 0 Layout : near=2 Chunk Size : 512K Name : pdwhost:10 (local to host pdwhost) UUID : a3de0ad5:9e694ee1:addc6786:c4449e40 Events : 0 Number Major Minor RaidDevice State 0 8 1 0 active sync /dev/sda1 1 8 81 1 active sync /dev/sdf1 2 8 97 2 active sync /dev/sdg1 3 8 113 3 active sync /dev/sdh1 does not really give any information about that. How it should be: Raid 1 / Mirror over /dev/sda1 /dev/sdf1 and /dev/sdg1 /dev/sdh1 Raid 0 over the two Raid 1 pairs Is it possible to do that with the built in "level=10", how can I see what pairs are mirrored? Thanks a lot for you help

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• mdadm lvm and ext4 slowness - How can I speed it up?

  - by beatbreaker

  I can't figure out why I'm getting such terrible times out of my mdadm and in particular the lvm partitions in it. I made the raid: mdadm --create --verbose /dev/md0 --level=5 --chunk=1024 --raid-devices=4 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1 # cat /proc/mdstat Personalities : [raid6] [raid5] [raid4] md0 : active raid5 sda1[0] sdd1[3] sdc1[2] sdb1[1] 2930279424 blocks level 5, 1024k chunk, algorithm 2 [4/4] [UUUU] I then created the physical volume, volume group, and logical volumes, I then formatted the logical volumes to ext4 using the following commands I got from here: http://busybox.net/~aldot/mkfs_stride.html mkfs.ext3 -b 4096 -E stride=256,stripe-width=768 /dev/datavg/blah Now I'm confused, I had these lvs running real quick before in mdadm but now that I've 'optimized' everything it's slower, eg, before: /dev/datavg/lv_audio: Timing buffered disk reads: 598 MB in 3.01 seconds = 198.85 MB/sec but now after: /dev/datavg/audio: Timing buffered disk reads: 198 MB in 3.00 seconds = 65.96 MB/sec That's pitiful! What's happened here? Did I not follow the instructions correctly? Can i reshape the ext4 partitons to default back to what they were? (I used defaults before and they were fine!)

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• The enterprise vendor con - connecting SSD's using SATA 2 (3Gbits) thus limiting there performance

  - by tonyrogerson

  When comparing SSD against Hard drive performance it really makes me cross when folk think comparing an array of SSD running on 3GBits/sec to hard drives running on 6GBits/second is somehow valid. In a paper from DELL (http://www.dell.com/downloads/global/products/pvaul/en/PowerEdge-PowerVaultH800-CacheCade-final.pdf) on increasing database performance using the DELL PERC H800 with Solid State Drives they compare four SSD drives connected at 3Gbits/sec against ten 10Krpm drives connected at 6Gbits [Tony slaps forehead while shouting DOH!]. It is true in the case of hard drives it probably doesn’t make much difference 3Gbit or 6Gbit because SAS and SATA are both end to end protocols rather than shared bus architecture like SCSI, so the hard drive doesn’t share bandwidth and probably can’t get near the 600MiBytes/second throughput that 6Gbit gives unless you are doing contiguous reads, in my own tests on a single 15Krpm SAS disk using IOMeter (8 worker threads, queue depth of 16 with a stripe size of 64KiB, an 8KiB transfer size on a drive formatted with an allocation size of 8KiB for a 100% sequential read test) I only get 347MiBytes per second sustained throughput at an average latency of 2.87ms per IO equating to 44.5K IOps, ok, if that was 3GBits it would be less – around 280MiBytes per second, oh, but wait a minute [...fingers tap desk] You’ll struggle to find in the commodity space an SSD that doesn’t have the SATA 3 (6GBits) interface, SSD’s are fast not only low latency and high IOps but they also offer a very large sustained transfer rate, consider the OCZ Agility 3 it so happens that in my masters dissertation I did the same test but on a difference box, I got 374MiBytes per second at an average latency of 2.67ms per IO equating to 47.9K IOps – cost of an 240GB Agility 3 is £174.24 (http://www.scan.co.uk/products/240gb-ocz-agility-3-ssd-25-sata-6gb-s-sandforce-2281-read-525mb-s-write-500mb-s-85k-iops), but that same drive set in a box connected with SATA 2 (3Gbits) would only yield around 280MiBytes per second thus losing almost 100MiBytes per second throughput and a ton of IOps too. So why the hell are “enterprise” vendors still only connecting SSD’s at 3GBits? Well, my conspiracy states that they have no interest in you moving to SSD because they’ll lose so much money, the argument that they use SATA 2 doesn’t wash, SATA 3 has been out for some time now and all the commodity stuff you buy uses it now. Consider the cost, not in terms of price per GB but price per IOps, SSD absolutely thrash Hard Drives on that, it was true that the opposite was also true that Hard Drives thrashed SSD’s on price per GB, but is that true now, I’m not so sure – a 300GByte 2.5” 15Krpm SAS drive costs £329.76 ex VAT (http://www.scan.co.uk/products/300gb-seagate-st9300653ss-savvio-15k3-25-hdd-sas-6gb-s-15000rpm-64mb-cache-27ms) which equates to £1.09 per GB compared to a 480GB OCZ Agility 3 costing £422.10 ex VAT (http://www.scan.co.uk/products/480gb-ocz-agility-3-ssd-25-sata-6gb-s-sandforce-2281-read-525mb-s-write-410mb-s-30k-iops) which equates to £0.88 per GB. Ok, I compared an “enterprise” hard drive with a “commodity” SSD, ok, so things get a little more complicated here, most “enterprise” SSD’s are SLC and most commodity are MLC, SLC gives more performance and wear, I’ll talk about that another day. For now though, don’t get sucked in by vendor marketing, SATA 2 (3Gbit) just doesn’t cut it, SSD need 6Gbit to breath and even that SSD’s are pushing. Alas, SSD’s are connected using SATA so all the controllers I’ve seen thus far from HP and DELL only do SATA 2 – deliberate? Well, I’ll let you decide on that one.

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• Comparing Isis, Google, and Paypal

  - by David Dorf

  Back in 2010 I was sure NFC would make great strides, but here we are two years later and NFC doesn't seem to be sticking. The obvious reason being the chicken-and-egg problem.  Retailers don't want to install the terminals until the phones support NFC, and vice-versa. So consumers continue to sit on the sidelines waiting for either side to blink and make the necessary investment.  In the meantime, EMV is looking for a way to sneak into the US with the help of the card brands. There are currently three major solutions that are battling in the marketplace.  All three know that replacing mag-stripe alone is not sufficient to move consumers.  Long-term it's the offers and loyalty programs combined with tendering that make NFC attractive. NFC solutions cross lots of barriers, so a strong partner system is required.  The solutions need to include the carriers, card brands, banks, handset manufacturers, POS terminals, and most of all lots of merchants.  Lots of coordination is necessary to make the solution seamless to the consumer. Google Wallet Google's problem has always been that only the Nexus phone has an NFC chip that supports their wallet.  There are a couple of additional phones out there now, but adoption is still slow.  They acquired Zavers a while back to incorporate digital coupons, but the the bulk of their users continue to be non-NFC.  They have taken an open approach by not specifying particular payment brands.  Google is piloting in San Francisco and New York, supporting both MasterCard PayPass and stored value. I suppose the other card brands may eventually follow.  There's no cost for consumers or merchants -- Google will make money via targeted ads. Isis Not long after Google announced its wallet, AT&T, Verizon, and T-Mobile announced a joint venture called Isis.  They are in the unique position of owning the SIM in the phones they issue.  At first it seemed Isis was a vehicle for the carriers to compete with the existing card brands, but Isis later switched to a generic wallet that supports the major card brands.  Isis reportedly charges issuers a $5 fee per customer per year.  Isis will pilot this summer in Salt Lake City and Austin. PayPal PayPal, the clear winner in the online payment space beyond traditional credit cards, is trying to move into physical stores.  After negotiations with Google to provide a wallet broke off, PayPal decided to avoid NFC altogether, at least for now, and focus on payments without any physical card or phone.  By avoiding NFC, consumers don't need an NFC-enabled phone and merchants don't need a new reader.  Consumers must enter their phone number and PIN in the merchant's existing device, or they can enter their PIN in the PayPal inStore app running on their phone, then show the merchant a unique barcode which authorizes payment. Paypal is free for consumers and charges a fee for merchants.  Its not clear, at least to me, how PayPal handles fraudulent transactions and whether the consumer is protected. The wildcard is, of course, Apple.  Their mobile technologies set the standard, so incorporating NFC chips would certainly accelerate adoption of many payment solutions.  Their announcement today of the iOS Passbook is a step in the right direction, but stops short of handling payments. For those retailers that have invested in modern terminals, it seems the best strategy is to support all the emerging solutions and let the consumers choose the winner.

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• UPOS RFIDScanner data format

  - by Robert Snyder

  A lot of work that I do currently is based in the OPOS/UPOS world. My company has a device that can read 13.56Mhz tags (RFID), Smart Cards, and Mag Stripe cards. Up until somewhat recently I have only been working with RFID for a very specific scenario. That was to read UltraLight C and Desfire cards. These cards were all setup very specifically so that I could take the data read from those cards and force it into a MSR track2 format. The past couple of weeks, however, I have been working on reading RFID credit cards (since I have a Visa card I've been using mine), and Smart Card credit cards. (The visa card I have has both) In learning how to communicate with SmartCard and reading ISO7816 and EMVCO documents I became a little more familiar with how info is stored. But now I have a question regarding UPOS. The RFID data on my Visa is stored (and read) very similar to how the data is stored and read from the Smart Card on my Visa. Cool. Well in the UPOS spec for SmartCardRW the ReadData method returns a byte array. That's cool, I can just return all that data and then parse it as my heart desires. The RFID though has a LinkedList of Tags. Well this makes sense in terms of my Visa card (reminds me of a question I have in regards to SmartCard, but that is for another question) but what about ULC and Desfire, or for that matter any Mifare card. Pages, Files, Purses don't exactly fit the Tag profile. For instance lets just say I read pages 4-12 on my ULC card. Each page I read is 4 bytes long. Does this mean I have 9 tags in my LinkedList? Is my Tag id the page number? Or then how does that translate to Desfire? I open application 123456 and read file 1 and file 2, Do I have 2 tags? and if so what is my tag id? At least with my Visa I think that I have to use the Tag id (ex 5F24 for my expiration date) and value of {0x15, 0x10, 0x31} Part of me says yes..that makes sense. Another part of me says, "well if that is the case then why doesn't SmartCardRW have Tags?" So that is my question. How do I format my data from those different types of media? or is that the job of my Control Object (the application)? Is so how does it know? The only protocols I have are: // Summary: // Enumerates the available predefined RFID tag protocols the device supports. [Flags] public enum RFIDProtocols { EpcClass0 = 1, RFIDSdt0Plus = 2, EpcClass1 = 4, EpcClass1Gen2 = 8, EpcClass2 = 16, Iso14443A = 4096, Iso14443B = 8192, Iso15693 = 12288, Iso180006B = 16384, Other = 16777216, All = 1073741824, } If I use that well all of my cards that I have are all Iso14443A. I use the ATQA and the SAK to know what type of card I really have. There is no RFID property that lets me specify that. So I'm lost.

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• jerky animation using Core Animation

  - by Paul from Boston

  In my iPhone app, I am trying to get some red and white stripes that are scrolling across the screen to animate smoothly when the speed of the stripes gets high. In my app the user starts the animation and changes the scrolling speed by a finger swipe and changes the width of the stripes by a two finger pinch. Animation is stopped in response to a double tap. If the speed gets high or the stripes get narrow the animation is no longer smooth to the eye. The edges of the stripes seem to jump around. The animation is simple. I draw the stripes in a layer that's a bit larger than the screen. I then set up an animation that moves the layer position by exactly the distance from one red stripe to the next. The duration is set by the speed of the finger swipe and the repeat count is 1. When the animation stops the delegate checks a flag to see if the user wants to stop the scrolling. If not, the animation is restarted again for one cycle. Are there better ways of doing this so that the animation is smooth at high speeds or with narrow stripes? Thanks--

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• Selecting a Java framework for large application w/ only ONE user

  - by Bijan

  I am building a large application that will be hosted on an AWS server. I'm trying to select a web framework for assisting me with code organization, template design, and generally presentation aspects. Here are some points of consideration: Require security/login/user authentication. I may add the ability in the future to allow more than just an administrator to access the web app, but it is not a public facing website. AJAX support would be helpful. There are a couple widgets that I don't want to recreate. One is a tree object, where the user can expand/contract items in the list, can create new branches, add/edit objects. This would be better off in some dynamic view rather than all done in ugly html. Generally, this is just to provide the application with a face for control, management, and monitoring. Having an easier time adding buttons, CSS, AJAX widgets are great additions though, but not the primary purpose. I'm considering: Wicket Spring Seam GWT Stripe and the list goes on, as I'm sure you all know. I originally planned on using GWT, but then started to feel that GWT didn't cover my primary needs. I could be wrong about this, but there seems to be a lot of support for GWT AND Wicket/Spring. All of this 'getting lost in java frameworks' got me thinking outside the java realm for a framework that would suit my needs that was a clear option, like: JRuby/Rails Jython/Django Groovy/Grails Guice (just throwing this in there... I don't clearly understand the main purposes of all these frameworks. It doesn't seem like DInjection is something I need for a single purpose application) Thanks as always. This community makes Googling for esoteric programming information an order of magnitude better.

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• Keyboard hook return different symbols from card reader depends whther my app in focus or not

  - by user363868

  I code WinForm application where one of the input is magnetic stripe card reader (CR). I am using code George Mamaladze's article Processing Global Mouse and Keyboard Hooks in C# on codeproject.com to listen keyboard (USB card reader acts same way as keyboard) and I have weird situation. One card reader CR1 (Unitech MS240-2UG) produces keystroke which I intercept on KeyPress event analyze that I intercept certain patter like %ABCD-6EFJHI? and trigger some logic. Analysis required because user can type something else into application or in another application meanwhile my app is open When I use another card reader CR2 (IdTech IDBM-334133) keystroke intercepted by hook started from number 5 instead of % (It is actually same key on keyboard). Since it is starting sentinel it is very important for me to have ability recognize input from card reader. Moreover if my app running in background and I have focus on Notepad when I swipe card string %ABCD-6EFJHI? appears in Notepad and same way, with proper starting character) intercepted by keyboard hook. If swiped when focus on Form it is 5ABCD-6EFJHI? User who tried app with another card reader has same result as me with CR2. Only CR1 works for me as expected I was looking into Device manager of Windows and both devices use same HID driver supplied by MS. I checked devices though respective software from CR makers and starting and ending sentinels set to % and ? respective on both. I would appreciate and ideas and thoughts as I hit the wall myself Thank you

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• Is it possible to achieve MAX(As,Ad) openGL blending?

  - by Jeff B

  I am working on a game where I want to create shadows under a series of sprites on a grid. The shadows are larger than the sprites themselves and the sprites are animated (i.e. move and rotate). I cannot simply render them into the sprite png, or the shadows will overlap adjacent sprites. I also cannot simply put shadows on a lower layer by themselves, because when they overlap, they will create dark bands at their intersection. These sprites are animated, so it is not feasible to render these en masse. Basically, I want the sprites' shadows to blend together such that they max out at a set opacity. Example: I believe this is equivalent to an openGL blending of (Rs,Gs,Bs,Max(As,Ds)), where I don't really care about R,G, and B, as it will always be the same color in src and dst. However, this is not a valid openGL blending mode. Is there an easy way to accomplish this, especially in cocos2d-iphone? I would be able to approximate this by making the shadow sprites opaque, then applying them both to a parent sprite, and making the parent sprite 40% opacity. However, the way cocos2d works, this only sets the opacity of each child to 40%, rather than the combined sprite image, which results in the same stripe.

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• How to have screen revert to BLACK between pages?

  - by user340667

  0 Hi - I tried out the Background Image Scaling script and with Cybr's update it works like magic. It SCALES the image perfectly. No distortion. BUT, my image isn't "computer friendly". I.e.: Not 1024 X 768 or even close to that. (Heck, my monitor has a wide screen, so it isn't 1024 X 768 either! Is anybody's anymore?) Anyhow, this creates a problem inasmuch as, unless I size the window from the bottom up it ends up with a white "stripe" beneath it. What I would REALLY like for it to do is have that white to be BLACK. My "usual" BG color/text etc. code is like: ""body bgcolor="#000000" text="#fcba1e" link="#0000ff" vlink="#800080" alink="#ff0000"" (Site won't let me add the arrows here.) I've tried inserting this in various places with no success. Any ideas for a workaround would surely be appreciated ! Thanks ! Bill

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• Alternating table row color, but with 2 rows of data

  - by PixelMuse

  I've got my table setup for Zebra striping, but how do I accomplish making the row color alternate for 2 rows instead of a single row? My data markup looks like this: <tr> <td>@task.TaskNum</td> <td>@task.RepiarTime</td> <td>Priority Club</td> <td>SD</td> <td>Commercial</td> <td>Reg Commercial</td> <td>After Hours</td> </tr> <tr><td colspan="7"> @task.Description.ToString() </td></tr> I am using this to stripe it: $(document).ready(function () { $(".stripeMe tr").mouseover(function () { $(this).addClass("over"); }).mouseout(function () { $(this).removeClass("over"); }); $(".stripeMe tr:even").addClass("alt"); });

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• 3Ware 9650SE RAID-6, two degraded drives, one ECC, rebuild stuck

  - by cswingle

  This morning I came in the office to discover that two of the drives on a RAID-6, 3ware 9650SE controller were marked as degraded and it was rebuilding the array. After getting to about 4%, it got ECC errors on a third drive (this may have happened when I attempted to access the filesystem on this RAID and got I/O errors from the controller). Now I'm in this state: > /c2/u1 show Unit UnitType Status %RCmpl %V/I/M Port Stripe Size(GB) ------------------------------------------------------------------------ u1 RAID-6 REBUILDING 4%(A) - - 64K 7450.5 u1-0 DISK OK - - p5 - 931.312 u1-1 DISK OK - - p2 - 931.312 u1-2 DISK OK - - p1 - 931.312 u1-3 DISK OK - - p4 - 931.312 u1-4 DISK OK - - p11 - 931.312 u1-5 DISK DEGRADED - - p6 - 931.312 u1-6 DISK OK - - p7 - 931.312 u1-7 DISK DEGRADED - - p3 - 931.312 u1-8 DISK WARNING - - p9 - 931.312 u1-9 DISK OK - - p10 - 931.312 u1/v0 Volume - - - - - 7450.5 Examining the SMART data on the three drives in question, the two that are DEGRADED are in good shape (PASSED without any Current_Pending_Sector or Offline_Uncorrectable errors), but the drive listed as WARNING has 24 uncorrectable sectors. And, the "rebuild" has been stuck at 4% for ten hours now. So: How do I get it to start actually rebuilding? This particular controller doesn't appear to support /c2/u1 resume rebuild, and the only rebuild command that appears to be an option is one that wants to know what disk to add (/c2/u1 start rebuild disk=<p:-p...> [ignoreECC] according to the help). I have two hot spares in the server, and I'm happy to engage them, but I don't understand what it would do with that information in the current state it's in. Can I pull out the drive that is demonstrably failing (the WARNING drive), when I have two DEGRADED drives in a RAID-6? It seems to me that the best scenario would be for me to pull the WARNING drive and tell it to use one of my hot spares in the rebuild. But won't I kill the thing by pulling a "good" drive in a RAID-6 with two DEGRADED drives? Finally, I've seen reference in other posts to a bad bug in this controller that causes good drives to be marked as bad and that upgrading the firmware may help. Is flashing the firmware a risky operation given the situation? Is it likely to help or hurt wrt the rebuilding-but-stuck-at-4% RAID? Am I experiencing this bug in action? Advice outside the spiritual would be much appreciated. Thanks.

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• LUKS with LVM, mount is not persistent after reboot

  - by linxsaga

  I have created a Logical vol and used luks to encrypt it. But while rebooting the server. I get a error message (below), therefore I would have to enter the root pass and disable the /etc/fstab entry. So mount of the LUKS partition is not persistent during reboot using LUKS. I have this setup on RHEL6 and wondering what i could be missing. I want to the LV to get be mount on reboot. Later I would want to replace it with UUID instead of the device name. Error message on reboot: "Give root password for maintenance (or type Control-D to continue):" Here are the steps from the beginning: [root@rhel6 ~]# pvcreate /dev/sdb Physical volume "/dev/sdb" successfully created [root@rhel6 ~]# vgcreate vg01 /dev/sdb Volume group "vg01" successfully created [root@rhel6 ~]# lvcreate --size 500M -n lvol1 vg01 Logical volume "lvol1" created [root@rhel6 ~]# lvdisplay --- Logical volume --- LV Name /dev/vg01/lvol1 VG Name vg01 LV UUID nX9DDe-ctqG-XCgO-2wcx-ddy4-i91Y-rZ5u91 LV Write Access read/write LV Status available # open 0 LV Size 500.00 MiB Current LE 125 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:0 [root@rhel6 ~]# cryptsetup luksFormat /dev/vg01/lvol1 WARNING! ======== This will overwrite data on /dev/vg01/lvol1 irrevocably. Are you sure? (Type uppercase yes): YES Enter LUKS passphrase: Verify passphrase: [root@rhel6 ~]# mkdir /house [root@rhel6 ~]# cryptsetup luksOpen /dev/vg01/lvol1 house Enter passphrase for /dev/vg01/lvol1: [root@rhel6 ~]# mkfs.ext4 /dev/mapper/house mke2fs 1.41.12 (17-May-2010) Filesystem label= OS type: Linux Block size=1024 (log=0) Fragment size=1024 (log=0) Stride=0 blocks, Stripe width=0 blocks 127512 inodes, 509952 blocks 25497 blocks (5.00%) reserved for the super user First data block=1 Maximum filesystem blocks=67633152 63 block groups 8192 blocks per group, 8192 fragments per group 2024 inodes per group Superblock backups stored on blocks: 8193, 24577, 40961, 57345, 73729, 204801, 221185, 401409 Writing inode tables: done Creating journal (8192 blocks): done Writing superblocks and filesystem accounting information: done This filesystem will be automatically checked every 21 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override. [root@rhel6 ~]# mount -t ext4 /dev/mapper/house /house PS: HERE I have successfully mounted: [root@rhel6 ~]# ls /house/ lost+found [root@rhel6 ~]# vim /etc/fstab -> as follow /dev/mapper/house /house ext4 defaults 1 2 [root@rhel6 ~]# vim /etc/crypttab -> entry as follows house /dev/vg01/lvol1 password [root@rhel6 ~]# mount -o remount /house [root@rhel6 ~]# ls /house/ lost+found [root@rhel6 ~]# umount /house/ [root@rhel6 ~]# mount -a -> SUCCESSFUL AGAIN [root@rhel6 ~]# ls /house/ lost+found Please let me know if I am missing anything here. Thanks in advance.

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• mounting ext4 fs with block size of 65536

  - by seaquest

  I am doing some benchmarking on EXT4 performance on Compact Flash media. I have created an ext4 fs with block size of 65536. however I can not mount it on ubuntu-10.10-netbook-i386. (it is already mounting ext4 fs with 4096 bytes of block sizes) According to my readings on ext4 it should allow such big block sized fs. I want to hear your comments. root@ubuntu:~# mkfs.ext4 -b 65536 /dev/sda3 Warning: blocksize 65536 not usable on most systems. mke2fs 1.41.12 (17-May-2010) mkfs.ext4: 65536-byte blocks too big for system (max 4096) Proceed anyway? (y,n) y Warning: 65536-byte blocks too big for system (max 4096), forced to continue Filesystem label= OS type: Linux Block size=65536 (log=6) Fragment size=65536 (log=6) Stride=0 blocks, Stripe width=0 blocks 19968 inodes, 19830 blocks 991 blocks (5.00%) reserved for the super user First data block=0 1 block group 65528 blocks per group, 65528 fragments per group 19968 inodes per group Writing inode tables: done Creating journal (1024 blocks): done Writing superblocks and filesystem accounting information: done This filesystem will be automatically checked every 37 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override. root@ubuntu:~# tune2fs -l /dev/sda3 tune2fs 1.41.12 (17-May-2010) Filesystem volume name: <none> Last mounted on: <not available> Filesystem UUID: 4cf3f507-e7b4-463c-be11-5b408097099b Filesystem magic number: 0xEF53 Filesystem revision #: 1 (dynamic) Filesystem features: has_journal ext_attr resize_inode dir_index filetype extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize Filesystem flags: signed_directory_hash Default mount options: (none) Filesystem state: clean Errors behavior: Continue Filesystem OS type: Linux Inode count: 19968 Block count: 19830 Reserved block count: 991 Free blocks: 18720 Free inodes: 19957 First block: 0 Block size: 65536 Fragment size: 65536 Blocks per group: 65528 Fragments per group: 65528 Inodes per group: 19968 Inode blocks per group: 78 Flex block group size: 16 Filesystem created: Sat Feb 5 14:39:55 2011 Last mount time: n/a Last write time: Sat Feb 5 14:40:02 2011 Mount count: 0 Maximum mount count: 37 Last checked: Sat Feb 5 14:39:55 2011 Check interval: 15552000 (6 months) Next check after: Thu Aug 4 14:39:55 2011 Lifetime writes: 70 MB Reserved blocks uid: 0 (user root) Reserved blocks gid: 0 (group root) First inode: 11 Inode size: 256 Required extra isize: 28 Desired extra isize: 28 Journal inode: 8 Default directory hash: half_md4 Directory Hash Seed: afb5b570-9d47-4786-bad2-4aacb3b73516 Journal backup: inode blocks root@ubuntu:~# mount -t ext4 /dev/sda3 /mnt/ mount: wrong fs type, bad option, bad superblock on /dev/sda3, missing codepage or helper program, or other error In some cases useful info is found in syslog - try dmesg | tail or so

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• Need advice on which PCI SATA Controller Card to Purchase

  - by Matt1776

  I have a major issue with the build of a machine I am trying to get up and running. My goal is to create a file server that will service the needs of my software development, personal media storage and streaming/media server needs, as well as provide a strong platform for backing up all this data in a routine, cron-job oriented German efficiency sort of way. The issue is a simple one - all my drives are SATA drives and my motherboard controller only contains 4 ports. Solving the issue has proven to be an unmitigated nightmare. I would like advice on the purchase of the following: 4 Port internal SATA / 2 Port external eSATA PCI SATA Controller Card that has the following features and/or advantages: It must function. If I plug it in and attach drives, I expect my system to still make it to the Operating System login screen. It must function on CentOS, and I mean it must function WELL and with MINIMAL hassle. If hassle is unavoidable, there shall be CLEAR CUT and EASY TO FOLLOW instructions on how to install drivers and other supporting software. I do not need nor want fakeRAID - I will be setting up any RAID configurations from within the operating system. Now, if I am able to find such a mythical device, I would be eternally grateful to whomever would be able to point me in the right direction, a direction which I assume will be paved with yellow bricks. I am prepared to pay a considerable sum of money (as SATA controller cards go) and so paying anywhere between 60 to 120 dollars will not be an issue whatsoever. Does such a magical device exist? The following link shows an "example" of the type of thing I am looking for, however, I have no way of verifying that once I plug this baby in that my system will still continue to function once I've attached the drives, or that once I've made it to the OS, I will be able to install whatever drivers or software programs I need to make it work with relative ease. It doesn't have to be dog-shit simple, but it cannot involve kernels or brain surgery. http://www.amazon.com/gp/product/B00552PLN4/ref=pd_lpo_k2_dp_sr_1?pf_rd_p=486539851&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B003GSGMPU&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=1HJG60XTZFJ48Z173HKY So does anyone have a suggestion regarding the subject I am asking about? PCI SATA Controller Cards? It would help if you've had experience with the component before - that is after all why I am asking here - for those who have had experience that I do not have. Bear in mind that this is for a home setup and that I do not have a company credit card. I have a budget with a 'relative' upper limit of about $150.00.

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