[NCSA-discuss] RAID recommendations?

[John W. Sopko Jr.]

My technique for managing the Dell raid has been:

- Use raid6 unless you are after more speed
- Boot the machine and go into raid bios
- configure 2 logical drives, one for the os and system partitions
   and the balance for the data partitions. These show up in Red Hat
   as drives sda and sdb
- Fdisk only allows 2TB max partitions so make your os/system drive less
   then 2TB
- Use lvm and create one large volume group and place on sdb
- Use lvm to create logical volumes in your one large volume group
- Use lvm to resize volumes, never mess with raid level utilities

If a drive fails it will flash yellow, I use Open Manage to monitor
changes in drive status. "Usually" you just remove the bad drive
and replace and the rebuild happens automatically. Of course it
is best to use the Open Manage tools to monitor things.

John Franklin wrote, On 12/17/2010 2:23 PM:
> I've had some professional experience with the Dell PERC RAID controllers, which are really rebadged MegaRAID controllers.  Overall, they've been solid and perform well.
>
> That said, there are a few issues I have with them, mostly in the administration side.  The RAID BIOS is useless for all but the most basic configuration tasks.  Resizing a RAID or doing any inspection of the RAID components requires using the MegaCLI, which is so finicky about is parameters and parameter order, and so poorly documented that you'll spend an hour on Google looking up what command options it expects and what the parameters mean.  A resize operation can take on the order of days to complete.
>
> The rest of the time, the card is a solid performer, supporting multiple RAID containers and VMs with ease.  I haven't tried RAID 6 with it, but it is supported.  If I were to build out a RAID container with 2TB drives (which have a disturbingly high failure rate), I'd want the extra protection of RAID 6.
>
> jf
>
> On Dec 17, 2010, at 1:31 PM, Dan Singer wrote:
>
>> Hello.  Wondering if anyone has any opinions on a RAID to buy -- or
>> avoid.  We're thinking about getting a RAID in the 8-16 TB range for
>> backup staging: backup to disk, copy to tape, leave the disk copy
>> around for a while.  No need for snapshots or other fancy features,
>> just capacity, speed, reliability, and ease of management are primary
>> considerations; direct attached to a *nix server.
>>
>> Just satisfied with your RAID?  Love it?  Hate it?
>>
>> Thanks.
>>
>> Dan
>>
>> --
>> Daniel E. Singer, System Administrator
>> Dept. of Computer Science, Duke University
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>
>
>
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-- 
John W. Sopko Jr.               University of North Carolina
email: sopko AT cs.unc.edu      Computer Science Dept., CB 3175
Phone: 919-962-1844             Fred Brooks Building; Room 140
Fax:   919-962-1799             Chapel Hill, NC 27599-3175