[CentOS] RAID 5 setup?

Christopher Chan christopher.chan at bradbury.edu.hk
Fri Mar 26 01:58:20 UTC 2010

On Friday, March 26, 2010 05:52 AM, Slack-Moehrle wrote:
>> As the disks get bigger, rebuild time also increases and the
>> performance of the disks don't increase linearly with their storage.
>> This means that when you are rebuilding a disk, the chances of one of
>> your other disks failing becomes significantly large. Most suggest
>> RAID6 these days as a minimum, mirroring and striping appears to be
>> the most popular.
> I looked up RAID6 and see the addition or a parity bit.
> http://en.wikipedia.org/wiki/Standard_RAID_levels#RAID_6

RAID6 allows you to survive failure of any two disks in the array at the 
cost of two disks of space.

> RAID 10 is also something I looked at. Striped, then Mirrored

They recommend that you mirror and then stripe the mirrors. But that is 
probably old school now with Neil Brown's raid10 personality. Does 
anyone do nested raid1+0 setups anymore?

> but with RAID 10, data is safe after many types of failures.

Except for the case when a mirror dies after which the whole thing is 
toast but in theory you can survive up to four disks going down.

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