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13

Thanks to Eric C. Singer for pointing me in the right direction - I've resolved this now, with much Googling. Here's what I had to do: Download MegaRAID SAS VMware SMIS Provider VIB from the Support & Downloads tab on this page. Enable SSH on my ESXi host. This involved the following steps: Go to the Configuration tab for the host in vSphere Client ...


10

The key to the answer to your question is read-ahead. Once upon a time, I also happened to have that issue. IOW, for optimal sequential read performance all disks should be permanently involved into Input. When you use dd w/o directio (see man dd), write operation is not being performed immediately, but goes through OS cache, so it has more chances to ...


8

Usually battery relearning refers to draining a battery in order to determine how long it holds a useful charge. In the case of a battery-backed write cache, this may be just to determine whether the battery is still good enough to trust your data to. Any useful write-caching solution must do this. It's unfortunate to have a hardware RAID solution that ...


8

poige is exactly right about the write cache, but here are more details. dd with zeros and using write cache is not the right way to benchmark (unless you want to test the write cache of course, which is probably only useful for a file system, to see how much it syncs metadata, creates new files, etc.) (and likely dd is always the wrong type of benchmark, ...


7

You should be able to compare the disk serial number from -pdlist with the output from lshw. # MegaCLI -pdlist -a0 | grep "Inquiry Data:" Inquiry Data: XXXXXXXXXXXXHitachi YYYYYYYY ZZZZZZ ... Then search the output of lshw for the serial number. The device name will be in the logical name field. I can't verify this because all of my ...


7

Are you trying to use the card for a software RAID solution like ZFS? Which controller are you using? If this is the case, using multiple RAID-0 logical drives will create an ugly situation if you need to swap a failed disk. The replacement drive will not be recognized until you reboot/reinitialize a new RAID-0 array containing the failed disk. It's not ...


5

You say you have an LSI 8-port internal SAS card. Unless you also have a SAS expander or enclosure (with an expander), you cannot connect 12 drives to an 8-port card... If you are connecting these 12 drives to both the LSI card and onboard SATA connectors, you cannot use any kind of hardware RAID setup - use Linux softraid (mdraid) instead.


5

When you open the Dashboard does it say the RAID is doing some Background Operations (Virtual drive operations in progress or Drive operations in progress) or Does the log say operations like Consistency Check started some time before the warning about the Patrol Read and some time after that it (Consistency Check) finished? Only my guess but: Check your ...


5

First off all, see this post: What are the different widely used RAID levels and when should I consider them Notice the difference between RAID 10 and RAID 01. Match this to your setups (both of them labeled as RAID 10 in your text). Look carefully. Read the part in the link I posted where it states: RAID 01 Good when: never Bad when: always ...


4

By partitions, do you mean that you want to create a single RAID array and then create more than one logical drive on that array? # Clear the RAID config megacli cfgclr -a0 # Create a RAID10 array from 4 drives with two logical drives, # one 100GB and one comprised of the rest of the space megacli cfgldadd -r1 "[?:0,?:1,?:2,?:3]" WB ADRA NoCachedBadBBU -...


4

The second configuration is what you want. Multiple RAID1 mirrors striped together. I don't understand why some controllers give people non-viable options.


4

You may want to test... But in general, hardware RAID controllers that can manage multiple volumes (logical drives, VD's, etc.) are handy in that they will allow the best use of the spindle count available to you. There's also a benefit to reliability. In short, I'd create an array of all disks and create appropriately-sized volumes within that.


3

Is someone shouting to your hard drives? :-) More seriously: is there lots of write activity during I/O latency spikes? Have you tried to use iotop and/or btrace to see what's going on under the hood? Perhaps the RAID controller flushes its cache during the spikes and blocks everything until it completes?


3

No, there's no such thing as "pressure" on hardware that causes damage. Likely what happened is that the MegaRAID software wasn't designed to handle a drive being switched off line by command while it was a functional part of a RAID array. I doubt the disk is actually damaged. More likely the controller just thought it was. If the drive actually is damaged, ...


3

Instead of using lshw, I think you can just use /dev/disk/by-path to get the relationship between the scsi target id and the logical device name(sdX). targetId=0;dev=`ls -l /dev/disk/by-path/ | grep -E "scsi-[0-9]:[0-9]:${targetId}:[0-9] " | awk '{print($11)}'`; echo ${dev##*\/} deviceId=$1 ldPdInfo=`$MegaCommand -LdPdInfo -aALL | grep -E 'Virtual ...


3

We managed to finally fix this issue. The ultimate cause and fix? It seems a manufacturing process error caused some JBODs shipped from Supermicro to come with a default burned in logical ID (the 0000007F). This address is actually supposed to match the SAS address by default. To fix this issue, we had to run a tool called ExpanderXtools Lite (ftp://...


3

It's the number of SMART errors on the physical disk.


3

No, this is not possible... HP Smart Array controllers and LSI have completely different on-disk RAID metadata formats. This will not work. The cable connecting the Smart Array P600 to the Storageworks MSA60 enclosure is not eSATA either. It's going to be a SFF-8470->SFF-8088 4-lane SAS cable. So, what problem are you trying to solve? You have a new ...


3

No. You cannot build a RAID 1 array with fewer than two drives.


3

http://www.lsi.com/downloads/Public/Host%20Bus%20Adapters/9206-16e_HBA_TemperatureAirflow_Application_Note.pdf This seems to give some idea about temperature ranges, although for a different chip. ~100°C is high and dangerously close to the limit but still within spec. I have a similar issue with a 9201-16i card. These chips have a 2000000 hours MTBF but at ...


3

By using a writeback cache, you are saving disk IOPS. The controller can batch up smaller writes into one big write. Thus, there are more IOPS available for reads. This assumes that the tests are concurrent. If a given test is only reads or only writes this won't matter.


3

LSI claim that their approach to RAID 10 differs from the standard definition because they follow the SNIA specification. With MegaRAID RAID 1 can consist of from two drives (the more traditional definition) to up to sixteen drives. MegaRAID RAID 1 must be an even number of drives. With MegaRAID 1, if more than two drives are in the Virtual Drive ...


3

There is a new version of the MegaCli: storCli. You can get it from here: http://www.lsi.com/support/pages/download-results.aspx?keyword=storcli In that archive is a Linux folder and you can install the package with rpm -ivh storcli-1.14.12-1.noarch.rpm. After that, you have a storcli64 in /opt/MegaRAID/storcli/ Works fine with XenServer 6.5.


3

Finally I got the solution. According to Fujitsu "LSI Logic MegaRAID SCSI WebBIOS Configuration Utility" User's guide, virtual disk initialization can be a good start to remove data from the disk: 1.4.5.1 Initialization The Initialize option initializes the selected logical drive by writing zeroes to the entire volume (if fast initialization is ...


2

On a newer version of MegaCLI (get it from http://www-947.ibm.com/support/entry/portal/docdisplay?lndocid=migr-5082327) you will get drive temp, with -PDList, tested on my servers. The additional problem would be the fact that for controller temp (also important) you need to have a temp sensor in place (it seems it does not come with one, at least AdpAllInfo ...


2

I run this exact setup. MegaCli has a useful option called something like CfgEachDskRaid0 which will configure every disk on the array as raid0, ensuring a consistent configuration. It's not true that it's impossible to hot swap disks with this setup, although it is clunky to do so (especially because MegaCli itself is hardly a paragon of usability), ...


2

Don't do this with 24 drives. Get a different controller. Anything based on the LSI 1068e (which is a bottom-of-the-line option for many Dell and IBM servers) will support JBOD. Dell calls it a SAS 6/iR and IBM calls it a ServeRAID BR10i.


2

Harry's command was very helpful, but I needed to go a step further and determine the pci device because I have multiple SAS adapters in my configuration. Figured I should share: vdisk=1 MegaCommand=/opt/MegaRAID/CmdTool2/CmdTool2 vendor_id=$($MegaCommand -AdpAllInfo -aALL \ | grep -E "^Vendor Id" \ | sed 's/.*: //g' ) device_id=$($...


2

I just added some support to my fork of megaclisas-status for matching the logical drive to an OS Native device. Here's an example output: $ sudo ./megaclisas-status -- Controller information -- -- ID | H/W Model | RAM | Temp | Firmware c0 | LSI MegaRAID SAS 9271-8i | 1024MB | 88C | FW: 23.32.0-0009 c1 | LSI MegaRAID SAS ...


2

I have been dealing with this across a number of new servers recently and I've come up with a solution! We are not using RAID on the "RAID" card, just using the SAS drives as JBOD. The /dev/disk/by-id mappings are off by one (or a few) from the SAS Address. This seems bizarre, but it works across dozens of servers I've tested it on. I have also received ...



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