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  • Why Constant Keyword is not introduced In Java?

    - by harigm
    I am curious learner of Java, I was thinking on one topic "CONSTANTS" I have learnt that Java allows us to declare constants by using "Final" keyword. My question is Java didnot introduce Constant(Const) Keyword. Since many people say it has come from C++, in C++ we have Const keyword Is there any strong reason behind, Please share your thoughts on this.

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  • Why is there no Constant keyword in Java?

    - by harigm
    I am curious learner of Java, and I was thinking about the topic of "CONSTANTS". I have learnt that Java allows us to declare constants by using final keyword. My question is why didn't Java introduce Constant (const) keyword. Since many people say it has come from C++, in C++ we have const keyword. Please share your thoughts.

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  • Oracle TimesTen In-Memory Database Performance on SPARC T4-2

    - by Brian
    The Oracle TimesTen In-Memory Database is optimized to run on Oracle's SPARC T4 processor platforms running Oracle Solaris 11 providing unsurpassed scalability, performance, upgradability, protection of investment and return on investment. The following demonstrate the value of combining Oracle TimesTen In-Memory Database with SPARC T4 servers and Oracle Solaris 11: On a Mobile Call Processing test, the 2-socket SPARC T4-2 server outperforms: Oracle's SPARC Enterprise M4000 server (4 x 2.66 GHz SPARC64 VII+) by 34%. Oracle's SPARC T3-4 (4 x 1.65 GHz SPARC T3) by 2.7x, or 5.4x per processor. Utilizing the TimesTen Performance Throughput Benchmark (TPTBM), the SPARC T4-2 server protects investments with: 2.1x the overall performance of a 4-socket SPARC Enterprise M4000 server in read-only mode and 1.5x the performance in update-only testing. This is 4.2x more performance per processor than the SPARC64 VII+ 2.66 GHz based system. 10x more performance per processor than the SPARC T2+ 1.4 GHz server. 1.6x better performance per processor than the SPARC T3 1.65 GHz based server. In replication testing, the two socket SPARC T4-2 server is over 3x faster than the performance of a four socket SPARC Enterprise T5440 server in both asynchronous replication environment and the highly available 2-Safe replication. This testing emphasizes parallel replication between systems. Performance Landscape Mobile Call Processing Test Performance System Processor Sockets/Cores/Threads Tps SPARC T4-2 SPARC T4, 2.85 GHz 2 16 128 218,400 M4000 SPARC64 VII+, 2.66 GHz 4 16 32 162,900 SPARC T3-4 SPARC T3, 1.65 GHz 4 64 512 80,400 TimesTen Performance Throughput Benchmark (TPTBM) Read-Only System Processor Sockets/Cores/Threads Tps SPARC T3-4 SPARC T3, 1.65 GHz 4 64 512 7.9M SPARC T4-2 SPARC T4, 2.85 GHz 2 16 128 6.5M M4000 SPARC64 VII+, 2.66 GHz 4 16 32 3.1M T5440 SPARC T2+, 1.4 GHz 4 32 256 3.1M TimesTen Performance Throughput Benchmark (TPTBM) Update-Only System Processor Sockets/Cores/Threads Tps SPARC T4-2 SPARC T4, 2.85 GHz 2 16 128 547,800 M4000 SPARC64 VII+, 2.66 GHz 4 16 32 363,800 SPARC T3-4 SPARC T3, 1.65 GHz 4 64 512 240,500 TimesTen Replication Tests System Processor Sockets/Cores/Threads Asynchronous 2-Safe SPARC T4-2 SPARC T4, 2.85 GHz 2 16 128 38,024 13,701 SPARC T5440 SPARC T2+, 1.4 GHz 4 32 256 11,621 4,615 Configuration Summary Hardware Configurations: SPARC T4-2 server 2 x SPARC T4 processors, 2.85 GHz 256 GB memory 1 x 8 Gbs FC Qlogic HBA 1 x 6 Gbs SAS HBA 4 x 300 GB internal disks Sun Storage F5100 Flash Array (40 x 24 GB flash modules) 1 x Sun Fire X4275 server configured as COMSTAR head SPARC T3-4 server 4 x SPARC T3 processors, 1.6 GHz 512 GB memory 1 x 8 Gbs FC Qlogic HBA 8 x 146 GB internal disks 1 x Sun Fire X4275 server configured as COMSTAR head SPARC Enterprise M4000 server 4 x SPARC64 VII+ processors, 2.66 GHz 128 GB memory 1 x 8 Gbs FC Qlogic HBA 1 x 6 Gbs SAS HBA 2 x 146 GB internal disks Sun Storage F5100 Flash Array (40 x 24 GB flash modules) 1 x Sun Fire X4275 server configured as COMSTAR head Software Configuration: Oracle Solaris 11 11/11 Oracle TimesTen 11.2.2.4 Benchmark Descriptions TimesTen Performance Throughput BenchMark (TPTBM) is shipped with TimesTen and measures the total throughput of the system. The workload can test read-only, update-only, delete and insert operations as required. Mobile Call Processing is a customer-based workload for processing calls made by mobile phone subscribers. The workload has a mixture of read-only, update, and insert-only transactions. The peak throughput performance is measured from multiple concurrent processes executing the transactions until a peak performance is reached via saturation of the available resources. Parallel Replication tests using both asynchronous and 2-Safe replication methods. For asynchronous replication, transactions are processed in batches to maximize the throughput capabilities of the replication server and network. In 2-Safe replication, also known as no data-loss or high availability, transactions are replicated between servers immediately emphasizing low latency. For both environments, performance is measured in the number of parallel replication servers and the maximum transactions-per-second for all concurrent processes. See Also SPARC T4-2 Server oracle.com OTN Oracle TimesTen In-Memory Database oracle.com OTN Oracle Solaris oracle.com OTN Oracle Database 11g Release 2 Enterprise Edition oracle.com OTN Disclosure Statement Copyright 2012, Oracle and/or its affiliates. All rights reserved. Oracle and Java are registered trademarks of Oracle and/or its affiliates. Other names may be trademarks of their respective owners. Results as of 1 October 2012.

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  • Why your Netapp is so slow...

    - by Darius Zanganeh
    Have you ever wondered why your Netapp FAS box is slow and doesn't perform well at large block workloads?  In this blog entry I will give you a little bit of information that will probably help you understand why it’s so slow, why you shouldn't use it for applications that read and write in large blocks like 64k, 128k, 256k ++ etc..  Of course since I work for Oracle at this time, I will show you why the ZS3 storage boxes are excellent choices for these types of workloads. Netapp’s Fundamental Problem The fundamental problem you have running these workloads on Netapp is the backend block size of their WAFL file system.  Every application block on a Netapp FAS ends up in a 4k chunk on a disk. Reference:  Netapp TR-3001 Whitepaper Netapp has proven this lacking large block performance fact in at least two different ways. They have NEVER posted an SPC-2 Benchmark yet they have posted SPC-1 and SPECSFS, both recently. In 2011 they purchased Engenio to try and fill this GAP in their portfolio. Block Size Matters So why does block size matter anyways?  Many applications use large block chunks of data especially in the Big Data movement.  Some examples are SAS Business Analytics, Microsoft SQL, Hadoop HDFS is even 64MB! Now let me boil this down for you.  If an application such MS SQL is writing data in a 64k chunk then before Netapp actually writes it on disk it will have to split it into 16 different 4k writes and 16 different disk IOPS.  When the application later goes to read that 64k chunk the Netapp will have to again do 16 different disk IOPS.  In comparison the ZS3 Storage Appliance can write in variable block sizes ranging from 512b to 1MB.  So if you put the same MSSQL database on a ZS3 you can set the specific LUNs for this database to 64k and then when you do an application read/write it requires only a single disk IO.  That is 16x faster!  But, back to the problem with your Netapp, you will VERY quickly run out of disk IO and hit a wall.  Now all arrays will have some fancy pre fetch algorithm and some nice cache and maybe even flash based cache such as a PAM card in your Netapp but with large block workloads you will usually blow through the cache and still need significant disk IO.  Also because these datasets are usually very large and usually not dedupable they are usually not good candidates for an all flash system.  You can do some simple math in excel and very quickly you will see why it matters.  Here are a couple of READ examples using SAS and MSSQL.  Assume these are the READ IOPS the application needs even after all the fancy cache and algorithms.   Here is an example with 128k blocks.  Notice the numbers of drives on the Netapp! Here is an example with 64k blocks You can easily see that the Oracle ZS3 can do dramatically more work with dramatically less drives.  This doesn't even take into account that the ONTAP system will likely run out of CPU way before you get to these drive numbers so you be buying many more controllers.  So with all that said, lets look at the ZS3 and why you should consider it for any workload your running on Netapp today.  ZS3 World Record Price/Performance in the SPC-2 benchmark ZS3-2 is #1 in Price Performance $12.08ZS3-2 is #3 in Overall Performance 16,212 MBPS Note: The number one overall spot in the world is held by an AFA 33,477 MBPS but at a Price Performance of $29.79.  A customer could purchase 2 x ZS3-2 systems in the benchmark with relatively the same performance and walk away with $600,000 in their pocket.

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  • VirtualBox 3.2 is released! A Red Letter Day?

    - by Fat Bloke
    Big news today! A new release of VirtualBox packed full of innovation and improvements. Over the next few weeks we'll take a closer look at some of these new features in a lot more depth, but today we'll whet your appetite with the headline descriptions. To start with, we should point out that this is the first Oracle-branded version which makes today a real Red-letter day ;-)  Oracle VM VirtualBox 3.2 Version 3.2 moves VirtualBox forward in 3 main areas ( handily, all beginning with "P" ) : performance, power and supported guest operating system platforms.  Let's take a look: Performance New Latest Intel hardware support - Harnessing the latest in chip-level support for virtualization, VirtualBox 3.2 supports new Intel Core i5 and i7 processor and Intel Xeon processor 5600 Series support for Unrestricted Guest Execution bringing faster boot times for everything from Windows to Solaris guests; New Large Page support - Reducing the size and overhead of key system resources, Large Page support delivers increased performance by enabling faster lookups and shorter table creation times. New In-hypervisor Networking - Significant optimization of the networking subsystem has reduced context switching between guests and host, increasing network throughput by up to 25%. New New Storage I/O subsystem - VirtualBox 3.2 offers a completely re-worked virtual disk subsystem which utilizes asynchronous I/O to achieve high-performance whilst maintaining high data integrity; New Remote Video Acceleration - The unique built-in VirtualBox Remote Display Protocol (VRDP), which is primarily used in virtual desktop infrastructure deployments, has been enhanced to deliver video acceleration. This delivers a rich user experience coupled with reduced computational expense, which is vital when servers are running hundreds of virtual machines; Power New Page Fusion - Traditional Page Sharing techniques have suffered from long and expensive cache construction as pages are scrutinized as candidates for de-duplication. Taking a smarter approach, VirtualBox Page Fusion uses intelligence in the guest virtual machine to determine much more rapidly and accurately those pages which can be eliminated thereby increasing the capacity or vm density of the system; New Memory Ballooning- Ballooning provides another method to increase vm density by allowing the memory of one guest to be recouped and made available to others; New Multiple Virtual Monitors - VirtualBox 3.2 now supports multi-headed virtual machines with up to 8 virtual monitors attached to a guest. Each virtual monitor can be a host window, or be mapped to the hosts physical monitors; New Hot-plug CPU's - Modern operating systems such Windows Server 2008 x64 Data Center Edition or the latest Linux server platforms allow CPUs to be dynamically inserted into a system to provide incremental computing power while the system is running. Version 3.2 introduces support for Hot-plug vCPUs, allowing VirtualBox virtual machines to be given more power, with zero-downtime of the guest; New Virtual SAS Controller - VirtualBox 3.2 now offers a virtual SAS controller, enabling it to run the most demanding of high-end guests; New Online Snapshot Merging - Snapshots are powerful but can eat up disk space and need to be pruned from time to time. Historically, machines have needed to be turned off to delete or merge snapshots but with VirtualBox 3.2 this operation can be done whilst the machines are running. This allows sophisticated system management with minimal interruption of operations; New OVF Enhancements - VirtualBox has supported the OVF standard for virtual machine portability for some time. Now with 3.2, VirtualBox specific configuration data is also stored in the standard allowing richer virtual machine definitions without compromising portability; New Guest Automation - The Guest Automation APIs allow host-based logic to drive operations in the guest; Platforms New USB Keyboard and Mouse - Support more guests that require USB input devices; New Oracle Enterprise Linux 5.5 - Support for the latest version of Oracle's flagship Linux platform; New Ubuntu 10.04 ("Lucid Lynx") - Support for both the desktop and server version of the popular Ubuntu Linux distribution; And as a man once said, "just one more thing" ... New Mac OS X (experimental) - On Apple hardware only, support for creating virtual machines run Mac OS X. All in all this is a pretty powerful release packed full of innovation and speedups. So what are you waiting for?  -FB 

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  • Wrong Ruby Float and BigDecimal subtraction result

    - by SamChandra
    I am running: [~/ruby/rails/sas]$ ruby --version ruby 1.8.7 (2009-06-08 patchlevel 173) [universal-darwin10.0] on Mac Snow Leopard 10.6.3 Can anyone help to explain why the Float and BigDecimal subtraction can be this wrong. [~/ruby/rails/sas]$ console Loading development environment (Rails 2.1.1) >> num = 30.0 => 30.0 >> num.class => Float >> ex = 28.04.to_d => #<BigDecimal:105367e40,'0.284E2',8(8)> >> ex.class => BigDecimal >> num - ex => 1.6 >> _.class => Float >> I was hoping that the result should be 1.96, I know that perhaps doing an arithmetic operation using 2 different data types are not recommended, but this behavior is so strange. It seems to be wise that from now on, I have to check the variables data type before doing any arithmetic operation. Hopefully somebody can give me an insight on what was happening.

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  • How do I set the LRECL in C#.NET?

    - by donde
    I have been trying to ftp a dtl file from .net to, what I beleive, is an AS400. The error being reported back to me is: "One or more lines have been truncated" and the admin is saying the file is coming over with 256 lines that have variable length columns. I found this explanation online: we have to establish defaults because no specifics about the file exist. The default RECFM is V and LRECL is 256. This means that SAS will scan the input record looking for the CR & LF to tell us that we are at the EOR. If the marker isn't found within the limit of the LRECL, SAS discards the data from the LRECL value to the end of the record and adds a message to the Log that "One or more lines have been truncated". So I need to set the LRECL. How do I do this in C# .NET? FtpWebRequest ftp = (FtpWebRequest)FtpWebRequest.Create(ftpfullpath); ftp.Credentials = new NetworkCredential(user, pwd); ftp.KeepAlive = false; ftp.UseBinary = false; ftp.Method = WebRequestMethods.Ftp.UploadFile; FileStream fs = File.OpenRead(inputfilepath + ftpfileName); byte[] buffer = new byte[fs.Length]; fs.Read(buffer, 0, buffer.Length); fs.Close(); Stream ftpstream = ftp.GetRequestStream(); int i = 0; int intBlock = 1786; int intBuffLeft = buffer.Length; while (i < buffer.Length) { if (intBuffLeft >= 1786) { ftpstream.Write(buffer, i, intBlock); } else { ftpstream.Write(buffer, i, intBuffLeft); } i += intBlock; intBuffLeft -= 1786; } ftpstream.Close();

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  • megacli forceWB

    - by Pascal den Bekker
    We are using a raid controller: LSI Logic / Symbios Logic MegaRAID SAS 2008 But there is no BBU on Board, is there a way to force the WB Cache ?? I tried following: - /opt/MegaRAID/MegaCli/MegaCli64 -LDSetProp CachedBadBBU -L0 -a0 Failed to set Write Cache OK if bad BBU on Adapter 0, VD 0. FW error description: The requested command has invalid arguments. Can anyone help? Cheers, Pascal

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  • All paths down on vSphere esxi 5.1, LSI 9211-8i

    - by user1434058
    Works 100% ESXi 5.1 HBA (LSI 1064e) 1x SAS2 100GB SSD Doesn't work ESXi 5.1 HBA (LSI 9211-8i IT /IBM M1015) 1x SAS2 100GB SSD After a few hours of heavy HD load i get: - Device or filesystem with identifier ['all drives'] has entered the All Paths Down state. - ESXi retries but loses connectivity to the SAS drive, marks it as "dead or error" - reboot fixes the issue How can i fix this issue?

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  • XenServer 6.0.2 path to installation media contains non-ascii characters

    - by cmaduro
    XenServer 6.0.2 install fails no matter what I do. I have confirmed that the md5 checksum on my ISO file is good. I tried installing from a mounted ISO file (remotely via iKVM). I tried installing from physical media. I tried installing from a bootable USB stick (using syslinux + contents of the ISO) All attempts have yielded the same result: When verifying the installation media, at 0% initializing, the following is reported: "Some packages appeared to be damaged." followed by a list of pretty much all the gz2 and rpm packages. If I skip the media verification the installer proceeds and then gives me an error when it reaches "Installing from base pack" at 0% which states "An unrecoverable error has occurred. The error was: 'ascii' codec can't decode byte 0xff in position 20710: ordinal not in range(128) Please refer to your user guide, or contact a Technical Support Representative, for further details" there is one option left which is to reboot. Apparently at some point during the processing of the repositories on the installation media non-ascii characters are found, which causes the installer to quit. How do I fix this? Here are my specs TYAN S8236 motherboard 2 AMD Opteron 6234 processors LSI2008 card connected to 2 1TB Seagate Constellation drives SATA, 1 500GB Corsair m4 SSD SATA and 1 Corsair Forse 3 - 64GB SSD SATA Onboard SATA connected to a slim DVD-+RW. Onboard SAS connected to 2 IBM ESX 70GB 10K SAS drives (for XenServer) 256GB memory ================================================================================= Comments: According to pylonsbook.com "chances are you have run into a problem with character sets, encodings, and Unicode" – cmaduro 10 hours ago A clue is provided by "vmware.com/support/vsphere5/doc/…; Data migration fails if the path to the vCenter Server installation media contains non-ASCII characters When this problem occurs, an error message similar to: 'ascii' codec can't decode byte 0xd0 in position 30: ordinal not in range(128) appears, and the installer quits unexpectedly during the data migration process. – cmaduro 10 hours ago This is an error that python throws. And guess what, the .py extention of the file you have to edit in this link community.spiceworks.com/how_to/show/1168 means the installer is written in python. Python is interpreted, so now to find the install file responsible for this error. – cmaduro 6 hours ago The file that generates the error upon verification is /opt/xensource/installer/tui/repo.py. The error message appears around line 359. – cmaduro 2 hours ago I am fairly sure that the install error is generated somewhere in repository.py as the backend.py file throws errors while methods in that file are being called. Perhaps all errors can be traced back to this file. – cmaduro 1 hour ago

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  • HP SmartArray P212 with non HP disks, Insight Diagnostics error

    - by yonatan
    I have an ML110 G6 with a SmartArray P212 and two Seagate (non-HP) SAS disks in Raid 1. When I ran HP Insight Diagnostics I got some errors related to S.M.A.R.T. error testing and I would like to confirm that this is due to the controller not being able to query the drives as they are non-HP. I believe that the drives are not failing, but I want to be sure. Please have a look at these screenshots I took from the Insight Diagnostics report:

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  • MD3200 - 3 to 4x less throughput than MD1220. Am I missing something here?

    - by Igor Polishchuk
    I have two R710 servers with similar configuration. One in my office has MD1220 attached. Another one in the datacenter of my hosting services vendor has MD3200. I'm getting significantly worse throughput from MD3200 at my vendors setup. I'm mostly interested in sequential writes, and I'm getting these results in bonnie++ and dd tests: Seq. writes on MD1220 in my office: 1.1 GB/s - bonnie++, 1.3GB/s - dd Seq. writes on MD3200 at my vendor's: 240MB/s - bonnie++, 310MB/s - dd Unfortunately, I could not test the exactly the same configurations, but the two I have should be comparable. If anything, my good performing environment is cheaper than the bad performing. I expect at least similar throughput from these two setups. My vendor cannot really help me. Hopefully, somebody more familiar with the DAS performance can look at it and tell if I'm missing something here and my expectations are too high. To summarize, the question here is it reasonable to expect about 100MB/s of sequential write throughput per each couple of drives in RAID10 on MD3200? Is there any trick to enable such performance in MD3200 with dual controller as opposed to simple MD1220 with a single H800 adapter? More details about the configurations: A good one in my office: Dell R710 2CPU X5650 @ 2.67GHz 12 cores 96GB DDR3, OS: RHEL 5.5, kernel 2.6.18-194.26.1.el5 x86_64 20x300GB 2.5" SAS 10K in a single RAID10 1MB chunk size on MD1220 + Dell H800 I/O controller with 1GB cache in the host Not so good one at my vendor's: Dell R710 2CPU L5520 @ 2.27GHz 8 cores 144GB DDR3, OS: RHEL 5.5, kernel 2.6.18-194.11.4.el5 x86_64 20x146GB 2.5" SAS 15K in a single RAID10 512KB chunk size, Dell MD3200, 2 I/O controllers in array with 1GB cache each Additional information. I've also ran the same tests on the same vendor's host, but the storage was: two raids of 14x146GB 15K RPM drives RAID 10, striped together on the OS level on MD3000+MD1000. The performance was about 25% worse than on MD3200 despite having more drives. When I ran similar tests on the internal storage of my vendor's host (2x146GB 15K RPM drives RAID1, Perc 6i) I've got about 128MB/s seq. writes. Just two internal drives gave me about a half of 20 drives' throughput on MD3200. The random I/O performance of the MD3200 setup is ok, it gives me at least 1300 IOPS. I'm mostly have problems with sequentioal I/O throughput. Thank you for looking into it. Regards Igor

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  • VMWare Esxi Looking for Bottlenecks

    - by nextgenneo
    I have a VMWare ESxi box, 22GB ram, Dual Quad Core Xeon, 2 Sas drives + Write caching raid controller etc. Anyways, have about 30 small XP VM's running on it and starting to get some very slow boot times and other performance issues. I THINK its I/O but looking at the graphs not too sure what to look for. Any ideas on what to look for would be appreciated. Here is the data I've got so far: (I feel like my IO is high but not sure what to bench it against)

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  • RAID options for a LAMP web server

    - by jetboy
    I'm due to set up a LAMP web server with four drives and a RAID controller to act as a web server. The drives are 146Gb SAS, and the machine has two quad core processors and 16Gb RAM. There will be very few write operations to the MySQL database, and I'll be using as much caching as possible to reduce disk I/O. Question is: Would I be better off splitting the drives into two RAID 1 arrays, splitting up sequential and random disk I/O, or would I get better overall performance putting them all in a single RAID 1+0 array?

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  • howto plan RAID for ESX

    - by maruti
    eight 300GB SAS drives are available. Can ESX be put on one disk as RAID-0 and others as RAID-5 ? so that in the event of disk failure data (VMs) are safe. if os disk RAID-0 fails could that be installed on replacement disk and still be able to keep VMs running? if not RAID-1 for OS is only option for OS disk? please suggest any other RAID options.

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  • HP DL380 G7 Disk swap to a HP DL380 G6

    - by rnuno
    The HP DL380 G7 has 3 SAS disks in RAID 5 configuration. I need to change that server to another task and instead of make a clean install on the HP DL380 G6 can i just swap the 3 disks from HP DL380 G7 to the HP DL380 G6? I expect some driver issues maybe on the OS itself because the processor is different. They both use Smart Array P410i, if i power down the machines swap the disk by the same order will the RAID 5 configuration remain and the OS will boot?

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  • How many disks is too many in this RAID 5 configuration??

    - by Tom
    HP 2012i SAN, 7 disks in RAID 5 with 1 hot spare, took several days to expand the volume from 5 to 7 300GB SAS drives. Looking for suggestions about when and how I would determine that having 2 volumes in the SAN, each one with RAID 5, would be better?? I can add 3 more drives to the controller someday, the SAN is used for ESX/vSphere VMs. Thank you...

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  • Why does unpartitioned Hitachi HDS5C3020 drive start consuming 50% more power 15 minutes after boot?

    - by Pro Backup
    In a Debian 6.0.6 system there are 74 pieces of 2TB Toshiba DT01ABA200 drives. These drives are identified as Hitachi HDS5C3020BLE630 drives running firmware revision MZ4OAAB0. 64 Drives attached via HP SAS expander cards to an LSI 2008 SAS controller, another 5 drives are connected directly to the mainboard, 4 drives are connected to a Sil based PCI controller and last 1 drive is only powered and has no data cable connected. The controller LSI and Sil card's their onboard BIOS are both disabled and the mpt2sas and sata_sil modules are removed from the Linux debian 2.6.32-5-amd64 #1 SMP Sun Sep 23 10:07:46 UTC 2012 x86_64 GNU/Linux kernel. The mpt2sas module is loaded after boot using a modprobe command in /etc/rc.local. These 74 drives are not partitioned, neither formatted and also not mounted. The system consumes: with 0 drives: 70.6 - 70.9 Watt (also 15 minutes after boot); with 74 drives: 330 - 360 Watt, just after boot (is equivalent to 3.5 - 3.9W per drive in idle state); with 74 drives: 420 - 466 Watt, each time in the 15th minute of uptime (is equivalent to 4.7 - 5.3W per drive in idle state). The drive specification lists 4.7W as read/write, and 3.3W as idle power consumption. The increased power consumption is most likely on the 5V line, because after roughly 1 minute an "over current protection" (OCP) of the power supply (PSU) shuts down the power. The used PSU is a single rail model with an OCP of 122A on the 12V line and 55A on the 5V line. Regression: It doesn't matter whether the drive its APM value is set to disabled or 1 (maximum power saving). The operating system records no read/write activity in /proc/diskstats. The values there are identical (28 read, 0 write operations) as immediately after the modprobe operation. Can't test what happens when booting into the mainboard it's BIOS - to exclude any OS intervention - because the Super Micro X8SI6-F mainboard running firmware 06/27/12 has a bug that incorrectly reads a +74.0 C CPU sensor temperature as "High" in BIOS mode, and shuts down the power after 1 minute. What might be causing the drive read/write activity on all drives in the 15th minute after boot and how to prevent it from happening?

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  • HP E200i Controlller RAID Configuration fon Win2008 Ent, Sql Server, IIS Apps etc need opinion

    - by mn
    Hello, Actually I run RAID 5 (4 x SAS drives) with Win 2008 Ent(1x host) Win 2008 End(3x guest) Sql Server 2005 Std (on guest) 3 x asp.net applications (on guest) I bought 3 x drives to create additional array (on same controller E200i, I am waiting now for confirmation is it possible to have 3 raids in same controller) I am planning to have 2 x RAID5 (if it is possible) first RAID 5 with all vhd files, systems etc second RAID 5 all data files and transaction logs I am looking for opinion how to optimize data layer (seven drives, one controller).

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