Search Results

Search found 11115 results on 445 pages for 'disk monitoring'.

Page 25/445 | < Previous Page | 21 22 23 24 25 26 27 28 29 30 31 32  | Next Page >

  • Automated monitoring of a remote system that sends email alerts.

    - by user23105
    I need to monitor a remote system where the only access I have is that I can subscribe to email alerts of completed/failed jobs. I would like a system that can monitor these emails and provide an SMS or other alert when: An email indicates failure. A process that was expected to complete by a given time has not. A process that was expected to complete N minutes after completion of another process has not completed. Are there any existing tools that allow this? I'd consider any option - SaaS, open-source, COTS, as long as I don't have to write it myself! Cheers, Blake

    Read the article

  • Are there any open-source simple network monitoring applications? [duplicate]

    - by scottm
    This question already has an answer here: What tool do you use to monitor your servers? 73 answers I am debugging a problem with one of our systems. Every Sunday, it stops communicating with another server. If we reboot both servers, communication works again. I was wondering if there are any small footprint apps that monitor TCP port availability and network connectivity, possibly logging any downtime. I'd also like it to be open source if possible, but if there is another solution that is proprietary, I'd like to hear about it also.

    Read the article

  • FairWarning Privacy Monitoring Solutions Rely on MySQL to Secure Patient Data

    - by Rebecca Hansen
    FairWarning® solutions have audited well over 120 billion events, each of which was processed and stored in a MySQL database. FairWarning is the world's leading supplier of privacy monitoring solutions for electronic health records, relied on by over 1,200 Hospitals and 5,000 Clinics to keep their patients' data safe. In January 2014, FairWarning was awarded the highest commendation in healthcare IT as the first ever Category Leader for Patient Privacy Monitoring in the "2013 Best in KLAS: Software & Services" report[1]. FairWarning has used MySQL as their solutions’ database from their start in 2005 to worldwide expansion and market leadership. FairWarning recently migrated their solutions from MyISAM to InnoDB and updated from MySQL 5.5 to 5.6. Following are some of benefits they’ve had as a result of those changes and reasons for their continued reliance on MySQL (from FairWarning MySQL Case Study). Scalability to Handle Terabytes of Data FairWarning's customers have a lot of data: On average, FairWarning customers receive over 700,000 events to be processed daily. Over 25% of their customers receive over 30 million events per day, which equates to over 1 billion events and nearly one terabyte (TB) of new data each month. Databases range in size from a few hundred GBs to 10+ TBs for enterprise deployments (data are rolled off after 13 months). Low or Zero Admin = Few DBAs "MySQL has not required a lot of administration. After it's been tuned, configured, and optimized for size on initial setup, we have very low administrative costs. I can scale and add more customers without adding DBAs. This has had a big, positive impact on our business.” - Chris Arnold, FairWarning Vice President of Product Management and Engineering. Performance Schema  As the size of FairWarning's customers has increased, so have their tables and data volumes. MySQL 5.6’ new maintenance and management features have helped FairWarning keep up. In particular, MySQL 5.6 performance schema’s low-level metrics have provided critical insight into how the system is performing and why. Support for Mutli-CPU Threads MySQL 5.6' support for multiple concurrent CPU threads, and FairWarning's custom data loader allow multiple files to load into a single table simultaneously vs. one at a time. As a result, their data load time has been reduced by 500%. MySQL Enterprise Hot Backup Because hospitals and clinics never stop, FairWarning solutions can’t either. FairWarning changed from using mysqldump to MySQL Enterprise Hot Backup, which has reduced downtime, restore time, and storage requirements. For many of their larger customers, restore time has decreased by 80%. MySQL Enterprise Edition and Product Roadmap Provide Complete Solution "MySQL's product roadmap fully addresses our needs. We like the fact that MySQL Enterprise Edition has everything included; there's no need to purchase separate modules."  - Chris Arnold Learn More>> FairWarning MySQL Case Study Why MySQL 5.6 is an Even Better Embedded Database for Your Products presentation Updating Your Products to MySQL 5.6, Best Practices for OEMs on-demand webinar (audio and / or slides + Q&A transcript) MyISAM to InnoDB – Why and How on-demand webinar (same stuff) Top 10 Reasons to Use MySQL as an Embedded Database white paper [1] 2013 Best in KLAS: Software & Services report, January, 2014. © 2014 KLAS Enterprises, LLC. All rights reserved.

    Read the article

  • How to diagnose disk errors when disk appears to be ok?

    - by Kylotan
    I have a six-month-old 1TB Seagate drive formatted into 2 NTFS partitions, and the disk appeared to be failing with Windows dropping down from UDMA to PIO mode, reporting Delayed Write Errors, and hanging Explorer when browsing directories. My initial suspicion was that the disk was dying. However, on further examination it appears that Ubuntu, which doesn't write to the volume frequently like Windows does, was able to read the disk properly and retrieve all the data intact, saving me from having to use an older backup. Finally, running the Seatools DOS diagnostic reported that the disk has no problems, ie. SMART errors and no bad sectors, apparently. This, in combination with the relative youth of the disk, suggests that something else is broken. The cable? The PSU? The integrated disk controller? But what would be a good way to diagnose the problem without risking damaging the data? I intend to extract the disk and try it in an external eSATA enclosure and see if the write errors cease, but in the event of the disk appearing to be fine, I would like to be able to confirm what part of the hardware is actually broken here in order to know just what needs replacing. Are there any good ways to go about this?

    Read the article

  • How to diagnose disk errors when disk appears to be ok?

    - by Kylotan
    I have a six-month-old 1TB Seagate drive formatted into 2 NTFS partitions, and the disk appeared to be failing with Windows dropping down from UDMA to PIO mode, reporting Delayed Write Errors, and hanging Explorer when browsing directories. My initial suspicion was that the disk was dying. However, on further examination it appears that Ubuntu, which doesn't write to the volume frequently like Windows does, was able to read the disk properly and retrieve all the data intact, saving me from having to use an older backup. Finally, running the Seatools DOS diagnostic reported that the disk has no problems, ie. SMART errors and no bad sectors, apparently. This, in combination with the relative youth of the disk, suggests that something else is broken. The cable? The PSU? The integrated disk controller? But what would be a good way to diagnose the problem without risking damaging the data? I intend to extract the disk and try it in an external eSATA enclosure and see if the write errors cease, but in the event of the disk appearing to be fine, I would like to be able to confirm what part of the hardware is actually broken here in order to know just what needs replacing. Are there any good ways to go about this?

    Read the article

  • Is there a way to know what the Windows Disk Cleanup utility will delete?

    - by Cam Jackson
    When I run the Disk Cleanup utility that's built into Windows 8, it tells me that it can free up 53GB by deleting 'Temporary Files'. However, a CCleaner analysis on default settings only finds about 300MB worth of space to free up, so I'm wondering what Disk Cleanup has found that CCleaner does not. Note that this question appears to be similar to what I'm asking, but the accepted answer says that 'Temporary Files' refers to %TEMP%. I've already cleared out most of C:\Users\Cam\AppData\Local\Temp, and it now has only 230MB of stuff in it, even with system files showing. So where is this 53GB located? Is there a way to find out what it is? Edit: I should note that this is on a 110GB SSD, so it's almost half the drive. And in fact I'm only using 86GB, so if it's really going to clear out 53GB, that would be more than 60% of the stuff on my C drive. I'm starting to think that Disk Cleanup caches its analysis, and hasn't updated since I started cleaning up the drive earlier today. Although when I run it it says that it's 'Calculating' how much space can be saved, and it takes about 5-10 seconds to do so. Hmmm... Edit2: Here is what my hard drive looks like, according to SpaceMonger (Right click-Open image in new tab, so you can see it properly): You can see why I was starting to think that the 53GB figure is actually wrong. Even if 'Temporary Files' includes my hiberfil and everything in WinSxS (about 13GB total), that would be 26GB, which is only halfway there. Hard to see where there's 53GB of stuff to delete.

    Read the article

  • Migrate Windows Server 2008 to a new hard disk 2

    - by MainMa
    Hi, A few weeks ago, I already asked how to move a Windows Server 2008 to a new hard disk. Despite the previous answers and two weeks lost trying to do it, I am always unable to move the OS to the new drive. What I tried: A backup/restore using Windows Backup. This never helped. First, I tried to backup, then copy the backup to a new drive, then restore. This results in "The parameter is incorrect. (0x80070057)" error caused by a bug in Windows Backup. Recently, I attempted to backup to a network share, but I can't restore from it, because of a "*The network path was not found. (0x80070035)" error. Trying the netsh interface ipv4 set address [...] does not work neither (saw at least three different errors, mostly "The interface is unknown.") A previously suggested solution using imagex from Windows AIK results in a non-bootable disk after writing an image to it. When booting from Windows 2008 installation disk (from USB), it finds that the HDD is not bootable and proposes to fix this, but then crashes, resulting in an unbootable USB flash disk (and HDD stays unbootable). As I said in my previous question, doing a clone of a hard disk drive gives an (of course) bootable disk, but Windows complain about hardware changes and cannot start. Now can somebody suggest me another way to move Windows Server 2008 to a new hard disk? Is it at least possible to do, or any hard disk failure/change implements necessarily to reinstall the whole OS?

    Read the article

  • Snapshotting single disk of running Hyper-V VM

    - by modelnine
    I'm currently somewhat at a loss of how to create a snapshot of a single virtual hard-disk of a running Hyper-V VM. Generally, creating a differential disk while a server is shut down is no problem (i.e., call the new-vhd cmdlet and pass a ParentPath, then update the VHD-binding of the respective VM-device), but while the host is running, all I can find is checkpointing the VM as a whole (which creates snapshots of all attached disks), and leaves the VM-state in a form which isn't easily processable by external tools (i.e., it requires reading additional meta-data from the VM). Generally, what'd I'd like to happen for a single-disk snapshot (in my understanding) is: Pause the VM Rename current disk to some other name which specifies it as a base-snapshot Create a new VHD which has the renamed VHD as parent path and is marked as "current" Swap the VHD for the VM for the snapshotted hard-disk to the newly created differential VHD Resume the VM Is there any means to do this programatically? Update: I've seen that this is actually possible with SCSI-disks, i.e. pause the VM, remove the SCSI disk, make the snapshot, reattach the SCSI disk at the same position, resume the VM. And, the VM resumes properly. But: is something similar also possible with G1 machines for the boot disk which is always IDE?

    Read the article

  • disk write cache buffer and separate power supply

    - by HugoRune
    Windows has a setting to turn off the write-cache buffer (see image) Turn off Windows write-cache buffer flushing on the device To prevent data loss, do not select this check box unless the device has a separate power supply that allows the device to flush its buffer in case of power failure. Is it feasible and economical to get such a "separate power supply" for the internal sata drives of a non-server PC? Under what name is such a power supply sold? I know that there are UPS devices that can be connected to external drives,but what is required to be able to switch this setting safely on for an internal disk? The setting has different descriptions in different version of windows Windows XP: Enable write caching on the disk This setting enables write caching in Windows to improve disk performance, but a power outage or equipment failure might result in data loss or corruption. Windows Server 2003: Enable write caching on the disk Recommended only for disks with a backup power supply. This setting further improves disk performance, but it also increases the risk of data loss if the disk loses power. Windows Vista: Enable advanced performance Recommended only for disks with a backup power supply. This setting further improves disk performance, but it also increases the risk of data loss if the disk loses power. Windows 7 and 8: Turn off Windows write-cache buffer flushing on the device To prevent data loss, do not select this check box unless the device has a separate power supply that allows the device to flush its buffer in case of power failure. This article by Raymond Chen has some more detailed information about what the setting does.

    Read the article

  • How to copy a floppy boot disk?

    - by Sammy
    I have a floppy boot disk and I would like to copy it to preserve it, as a backup. If I have two floppy drives, A and B, how can I copy the disk? Assuming one has two floppy drives Can I simply insert the floppy disk in one of the drives and then an empty floppy disk in the other and issue a simple command like this one. A:\>copy . b: Will this only copy the contents of the current directory and none of the files in subdirectories? Do I have to explicitly specify the option to copy everything? Also, what about the boot information? That won't get copied, right? If one has only one floppy drive... How do you copy a floppy disk if you only have one floppy drive? Do you in fact have to copy its contents to the local hard drive C and then copy that to an empty floppy disk using the same floppy drive? A:\>copy . c:\floppydisk A:\> A:\>c: C:\> C:\>copy floppydisk a: C:\> I'm guessing I will need some type of disk image tool to really copy everything on a bootable floppy disk. Something like the dd command on Linux perhaps? Am I right?

    Read the article

  • How many guesses per second are possible against an encrypted disk? [closed]

    - by HappyDeveloper
    I understand that guesses per second depends on the hardware and the encryption algorithm, so I don't expect an absolute number as answer. For example, with an average machine you can make a lot (thousands?) of guesses per second for a hash created with a single md5 round, because md5 is fast, making brute force and dictionary attacks a real danger for most passwords. But if instead you use bcrypt with enough rounds, you can slow the attack down to 1 guess per second, for example. 1) So how does disk encryption usually work? This is how I imagine it, tell me if it is close to reality: When I enter the passphrase, it is hashed with a slow algorithm to generate a key (always the same?). Because this is slow, brute force is not a good approach to break it. Then, with the generated key, the disk is unencrypted on the fly very fast, so there is not a significant performance lose. 2) How can I test this with my own machine? I want to calculate the guesses per second my machine can make. 3) How many guesses per second are possible against an encrypted disk with the fastest PC ever so far?

    Read the article

  • How to Find Out Who Made an ISO Disk?

    - by Qwertyfshag
    If a file is saved using Microsoft word or some other type of program, you can right click on the file to find the properties, which will indicate the computer that created the file. Is there anyway to find out who created an ISO disk image on a CD or DVD? I assume that there should be no meta data on the disk because an ISO disk image should be an exact duplicate of the original. Is my assumption correct? To illustrate with an example, let's say you found a CD at a cafe or something. You decide to look at the CD with your computer. You find out that it is an "Ubuntu live CD" that was obviously created from an ISO file. Is there any way to find out who burned the CD? Or, on the flip side, let's say you were the one that burned the "Ubuntu live CD" and you lost it. Would somebody be able to know that it was you who made the CD? Can they get any info about the maker?

    Read the article

  • Practical Performance Monitoring and Tuning Event

    - by Andrew Kelly
      For any of you who may be interested or know of someone in the market for a performance Monitoring and Tuning class I have just the ticket for you. It’s a 3 day event that will be held in Atlanta Ga. on January 25th to the 27th 2011. For those of you that know me or have been to my sessions you realize I like to provide more than just classroom theory and like to teach real world and above all practical methodology when it comes to performance in SQL Server. This class covers all the essentials...(read more)

    Read the article

  • Monitoring Database disk space

    - by Michael Freidgeim
    An article Data files: To Autogrow Or Not To Autogrow? recommends NOT to rely on auto-grow, because it causing delays in unplanned times.We should mtonitor database files(both data and log), and if they close to max capacity, manually increase the size. However it doesn't give references, how to monitor the free space inside databases. I've tried to look how to do it. It can be done manually using   execute sp_spaceused for the database in question or  sp_SOS (can be downloaded from http://searchsqlserver.techtarget.com/tip/Find-size-of-SQL-Server-tables-and-other-objects-with-stored-procedure)Alternatively you can run SQL commands as suggested in Http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=82359 by Michael Valentine Jonesselect [FREE_SPACE_MB] = convert(decimal(12,2),round((a.size-fileproperty(a.name,'SpaceUsed'))/128.000,2)) from dbo.sysfiles aMore useful article Monitor database file sizes with SQL Server Jobs describes how to setup monitoring Finally I found the excellent articleManaging Database Data Usage With Custom Space Alerts, that can be followed even support personnel without much DBA experience.

    Read the article

  • Gparted Partition Mount Points Alternate Between 2 Physical Disk Drives

    - by California Ken
    I'm running Ubuntu Server 14.04 on a system with 2 physical disk drives. I am frequently seeing mount errors on startup. When I check the drive partitions using GPARTED, I see that my two "non-system created" data partitions have the wrong disk assignments (i.e. sda1 vs sdb1) or visa-versa. If I hand edit /etc/fstab to match GPARTED, the system will boot error free one time. On the second restart I will get the "serious mount problem" error for the 2 data partitions and when I check GPARTED, the disk assignments have changed again (again, GPARTED and fstab don't match). A listing of my /etc/fstab is: /etc/fstab: static file system information. # Use 'blkid' to print the universally unique identifier for a device; this may be used with UUID= as a more robust way to name devices that works even if disks are added and removed. See fstab(5). # / was on /dev/sdb2 during installation UUID=766a06a4-e5af-484a-adf0-fa1e88da7212 / ext4 errors=remount-ro,user_xattr,acl,barrier=1 0 1 swap was on /dev/sda6 during installation UUID=8c42f835-ead3-43fb-88d8-196f5dfc3aa7 none swap sw 0 0 swap was on /dev/sdb3 during installation UUID=2214deec-ba98-47da-aea7-4e46998f3e57 none swap sw 0 0 /dev/fd0 /media/floppy0 auto rw,user,noauto,exec,utf8 0 0 /dev/sda1 /media/ken/Linux-Data ext3 defaults 0 2 /dev/sda5 /media/ken/Data2 ext4 defaults 0 2 The device designations in the last 2 lines are the ones in question. The fstab entries to NOT change between system restarts but the mount points in the GPARTED display do. Does anyone have a fix for this? Thanks Mr. Young and Mr Gedak, Following is my fstab file and two blkid outputs. The fstab output is correct. The first blkid output was after a reboot and is WRONG! The sda and sdb device partition data is reversed. The 2nd blkid output was after a second reboot (fstab not changed). It shows the sda and adb partition data CORRECTLY. I didn't see any duplicate UUIDs. Does anyone have any idea why the GPARTED and blkid outputs alternate on consecutive reboots? The alternating partition data is real since when the partition assignments are reversed, the boot sequence halts with disk mounting errers (I have to press "s" to skip the mounts). Thanks again. Ken I copied the contents of a text file showing my fstab and 2 blkid outputs. The text file contents show up in the text entry box but does not appear in the main body of the question. Is there a way I can attach the text file or edit this question so that the text is displayed for question viewers?

    Read the article

  • Mounting a usb floppy disk drive in Ubuntu 11.04

    - by Jocky B
    I have tried to mount my usb floppy disk drive in 11.04 Natty. So far I have managed to use the udisks --mount/dev/sdf command in terminal, but get a message that I have not stated a filetype "john@john-desktop:~$ udisks --mount /dev/sdf Mount failed: Error mounting: mount: you must specify the filesystem type" This is the result I get when trying to mount the usb floppy disk drive. Anyone know how to proceed Cheers

    Read the article

  • What You Said: How You Monitor Your Computer

    - by Jason Fitzpatrick
    Earlier this week we asked you to share your computer monitoring tips and tricks, now we’re back to share the wealth. Read on to see how your fellow reader monitor their gear. One of the more popular monitoring tools, thanks in part to the amount of things beyond just hardware it can monitor, in the comments was Rainmeter. Lee writes: I don’t really monitor my computer constantly, only when something is hanging up and I need to see what’s causing it. That being said, I do have Rainmeter so I can quickly see how much RAM or CPU is being used. For anything more detailed, I just go into the task manager and sort by RAM or CPU. Shinigamibob uses a wider range of tools to get a more in-depth look at difference aspects of his computer: 7 Ways To Free Up Hard Disk Space On Windows HTG Explains: How System Restore Works in Windows HTG Explains: How Antivirus Software Works

    Read the article

  • Inconsistencies in Health Monitoring Between WebForms and MVC

    As I have written and spoken on numerous occasions, Health Monitoring happens to be one of my favorite features in ASP.NET. In WebForms, it's a path well trodden. However, while building Morts & Elvises with MVC2, I ran into a strange inconsistency, which I'd like to describe here. WebForms Whenever a WebForm throws an unhandled exception, at the very least the error is written to the system's even log. Suppose we have this silly simple page method: protected override void OnLoad...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

    Read the article

  • The Birth and Life of a Disk Galaxy [Video]

    - by Jason Fitzpatrick
    In this video, rendered over a million CPU hours by the Pleiades supercomputer at NASA’s Ames Research Center, we see the birth and life of a massive disk galaxy. Computer Model Shows a Disk Galaxy’s Life History [via Geeks Are Sexy] HTG Explains: Why It’s Good That Your Computer’s RAM Is Full 10 Awesome Improvements For Desktop Users in Windows 8 How To Play DVDs on Windows 8

    Read the article

  • Google page events monitoring and analysis

    - by Homunculus Reticulli
    I have read the Google page event documentation, but I am not sure I understand it correctly. I am new to Google analytics, and I have two questions: Once I have google analytics enabled for my site (i.e. I have inserted the tracking code in my pages etc), do I need to set anything else up (at the Google end - i.e. in my Google analytics account) It is not clear to me how the event data particularly, relating to how the data can be aggregated and analyzed. For instance, if I want to track an event under category category for click action action, I will use the following code snippet: <a href="some-uri.htm" onclick="_gaq.push(['_trackEvent', 'category', 'action', 'label']);">Do Something</a> For the sake of simplicity, lets say I am interested in monitoring click events in my header and footer, and I want to find which pages the header and or footer is clicked most often. How would I set things up so that I can analyze the header/footer clicks aggregated at the page level?

    Read the article

  • 7 Ways To Free Up Hard Disk Space On Windows

    - by Chris Hoffman
    Hard drives are getting larger and larger, but somehow they always seem to fill up. This is even more true if you’re using a solid-state drive (SSD), which offers much less hard drive space than traditional mechanical hard drives. If you’re hurting for hard drive space, these tricks should help you free up space for important files and programs by removing the unimportant junk cluttering up your hard disk. Image Credit: Jason Bache on Flickr 7 Ways To Free Up Hard Disk Space On Windows HTG Explains: How System Restore Works in Windows HTG Explains: How Antivirus Software Works

    Read the article

  • SQLServerCentral Webinar Series #21 - Forgotten Rings & Other Monitoring Stories

    Most common monitoring metrics are important and useful, especially over time, but they can fall short. How do you gather information to determine, for example, if you have buffer cache pressure? Register now for the free webinar. Wednesday, October 17 2012 4:00pm - 5:00pm BST Are you sure you can restore your backups? Run full restore + DBCC CHECKDB quickly and easily with SQL Backup Pro's new automated verification. Check for corruption and prepare for when disaster strikes. Try it now.

    Read the article

  • Avoid random disk names

    - by BarsMonster
    Hi! I have Ubuntu Server 10.04 1 system disk, and 5 disks in RAID-5 configuration. The problem is that names of these disks are changed from time to time, they are being randomly mixed from time to time (sda,b,c,d,e,f - so system disks might be sda, or sdc at different time for example).... is there any way to fix drive names, so that even if it's disconnected for example, no other drive can occupy this letter based on disk UUID or something?

    Read the article

  • A proper file monitoring tool for Windows with notifications

    - by nevvermind
    Developing in PHP, I'm usually confronted with various log files: apache, web apps, error logs etc. I'm currently using Notepad++ with the option to notify me when a file has changed. But when I need to monitor many files, I end up with too many tabs opened. I've used some of these, but they were lacking some basic stuff (like double clicking on the file to open it; oh, c'mon). What do you guys use for monitoring file changes? I needn't be "modern" or fancy. Just a simple "Hey, this file was changed. Here, click on it to open". (Maybe I'll end up making one myself, but I need to learn some more Java).

    Read the article

  • What free space thresholds/limits are advisable for 640 GB and 2 TB hard disk drives with ZEVO ZFS on OS X?

    - by Graham Perrin
    Assuming that free space advice for ZEVO will not differ from advice for other modern implementations of ZFS … Question Please, what percentages or amounts of free space are advisable for hard disk drives of the following sizes? 640 GB 2 TB Thoughts A standard answer for modern implementations of ZFS might be "no more than 96 percent full". However if apply that to (say) a single-disk 640 GB dataset where some of the files most commonly used (by VirtualBox) are larger than 15 GB each, then I guess that blocks for those files will become sub optimally spread across the platters with around 26 GB free. I read that in most cases, fragmentation and defragmentation should not be a concern with ZFS. Sill, I like the mental picture of most fragments of a large .vdi in reasonably close proximity to each other. (Do features of ZFS make that wish for proximity too old-fashioned?) Side note: there might arise the question of how to optimise performance after a threshold is 'broken'. If it arises, I'll keep it separate. Background On a 640 GB StoreJet Transcend (product ID 0x2329) in the past I probably went beyond an advisable threshold. Currently the largest file is around 17 GB –  – and I doubt that any .vdi or other file on this disk will grow beyond 40 GB. (Ignore the purple masses, those are bundles of 8 MB band files.) Without HFS Plus: the thresholds of twenty, ten and five percent that I associate with Mobile Time Machine file system need not apply. I currently use ZEVO Community Edition 1.1.1 with Mountain Lion, OS X 10.8.2, but I'd like answers to be not too version-specific. References, chronological order ZFS Block Allocation (Jeff Bonwick's Blog) (2006-11-04) Space Maps (Jeff Bonwick's Blog) (2007-09-13) Doubling Exchange Performance (Bizarre ! Vous avez dit Bizarre ?) (2010-03-11) … So to solve this problem, what went in 2010/Q1 software release is multifold. The most important thing is: we increased the threshold at which we switched from 'first fit' (go fast) to 'best fit' (pack tight) from 70% full to 96% full. With TB drives, each slab is at least 5GB and 4% is still 200MB plenty of space and no need to do anything radical before that. This gave us the biggest bang. Second, instead of trying to reuse the same primary slabs until it failed an allocation we decided to stop giving the primary slab this preferential threatment as soon as the biggest allocation that could be satisfied by a slab was down to 128K (metaslab_df_alloc_threshold). At that point we were ready to switch to another slab that had more free space. We also decided to reduce the SMO bonus. Before, a slab that was 50% empty was preferred over slabs that had never been used. In order to foster more write aggregation, we reduced the threshold to 33% empty. This means that a random write workload now spread to more slabs where each one will have larger amount of free space leading to more write aggregation. Finally we also saw that slab loading was contributing to lower performance and implemented a slab prefetch mechanism to reduce down time associated with that operation. The conjunction of all these changes lead to 50% improved OLTP and 70% reduced variability from run to run … OLTP Improvements in Sun Storage 7000 2010.Q1 (Performance Profiles) (2010-03-11) Alasdair on Everything » ZFS runs really slowly when free disk usage goes above 80% (2010-07-18) where commentary includes: … OpenSolaris has changed this in onnv revision 11146 … [CFT] Improved ZFS metaslab code (faster write speed) (2010-08-22)

    Read the article

< Previous Page | 21 22 23 24 25 26 27 28 29 30 31 32  | Next Page >