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Hazy Arc

join:2006-04-10
Greenwood, SC
Reviews:
·CenturyLink
·Embarq Now Centu..

RAID 5 Question

Hi All:

We recently received a new server that contained 9 900GB drives (one being a hot spare). We need to create virtual disks with a size of less than 2000GB due to the OS we're installing. Is it safer to create a single RAID container across all of the disks and create 4 VDs to split the capacity, or to create multiple RAIDs containing just 3 disks a piece?



DarkLogix
Texan and Proud
Premium
join:2008-10-23
Baytown, TX
kudos:3

I'd make a 9 drive raid 5 then make volumes at 2048GB.


snowsam

join:2001-04-11
Signal Mountain, TN
reply to Hazy Arc

What kind of drives?

Do you need to consider raid 6 or raid 10 instead of raid 5, due to the potential for seeing a URE during a rebuild if you do have a failure on a drive?

See »community.spiceworks.com/topic/1···y-978663


mikefxu

join:2004-10-05
Titusville, FL
reply to Hazy Arc

RAID 10.....not really enough information to make a recommendation.


AsherN
Premium
join:2010-08-23
Thornhill, ON
reply to Hazy Arc

RAID10.

RAID5 is no longer recommended. Dell has even removed the option from the latest firmaware for ll their arrays.

a RAID5 set that size may never rebuild.



The WeaseL
Premium
join:2001-12-03
Minnesota
reply to Hazy Arc

I have a 12 disk raid 5 running across 2 TB SATA drives that needed to rebuild a disk and it went fine in our MSA, you can get away with it. We are using it for ip camera data so in the event of a data loss failure we aren't out much.

Without knowing anything beyond 9 900 GB drives, I'd probably say 8 disk RAID 10 with hot spare if I had to pick anything based on the info provided. Then create volumes within the raid set.
--
How lucky am I to have known someone who is so hard to say good-bye to.



DarkLogix
Texan and Proud
Premium
join:2008-10-23
Baytown, TX
kudos:3

I've had many 8 drive raid 5 arrays rebuild without issue

last one was a live upgrade from 8x 146gb sas 10k drives to 8x 300gb sas 10k drives.
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»Death Star Petition


AsherN
Premium
join:2010-08-23
Thornhill, ON
reply to The WeaseL

And I have a few of those too. Used as the target for my backups. RAID5 is OK if you need some protection for data that can be lost.

I'd never trust large arrays to RAID5



urbanriot
Premium
join:2004-10-18
Canada
kudos:3
Reviews:
·Cogeco Cable
reply to AsherN

said by AsherN:

a RAID5 set that size may never rebuild.

... what? I've seen arrays of 20 TB rebuild just fine. I find it odd that I even have to respond to such an odd statement.

I've seen more recoverable resiliency, without a loss of operations, with large RAID 6 volumes than I have with RAID 10. I've seen more non-booting failed RAID 10 cluster nodes than I have RAID 5 or RAID 6, although I've seen more RAID 5 arrays fall victim to outright drive failure + anomalous issue drives, so for me it's a toss-up. RAID 6 + hot spares + fast controller CPU for fast rebuilds is usually the quickest method of recovery that I've encountered.

mkaishar

join:2000-12-20
united state
reply to Hazy Arc

So I guess my pair of HA 24 x 1TB HDDs running RAID-50 (single 18TB usable per unit) not gonna rebuild?

I did have a failed drive and it rebuilt fine in production, albeit slow, but it worked.


AsherN
Premium
join:2010-08-23
Thornhill, ON
reply to urbanriot

said by urbanriot:

said by AsherN:

a RAID5 set that size may never rebuild.

... what? I've seen arrays of 20 TB rebuild just fine. I find it odd that I even have to respond to such an odd statement.

I've seen more recoverable resiliency, without a loss of operations, with large RAID 6 volumes than I have with RAID 10. I've seen more non-booting failed RAID 10 cluster nodes than I have RAID 5 or RAID 6, although I've seen more RAID 5 arrays fall victim to outright drive failure + anomalous issue drives, so for me it's a toss-up. RAID 6 + hot spares + fast controller CPU for fast rebuilds is usually the quickest method of recovery that I've encountered.

It's not that a large RAID5 array will never rebuild. it's that the odds are against you. RAID6 helps. So does RAID 50. Overall, RAID10 provides better protection, faster rebuilds, less write penalty and faster reads.


exocet_cm
Free at last, free at last
Premium
join:2003-03-23
New Orleans, LA
kudos:3
reply to Hazy Arc

With our arrays I went the RAID 6 route but in a few months will reconfigure them for RAID 10.
In your case RAID 10 of 8 drives with a single HS.

Edit: OP, what OS are you using? Some VM solution?



Hazy Arc

join:2006-04-10
Greenwood, SC

We are running VMware ESXi with 10K SAS drives.


dougis

join:2000-05-02
Everett, WA
reply to Hazy Arc

I would echo what others have said.
Raid 10 with a HS.
A single data store and let ESXi manage your VHDs and their size.

You do realize you are at a spf with your storage correct?