[CentOS] 4 X 500 gb drives - best software raid config for a backup server?

Sun Feb 22 00:09:56 UTC 2009
Les Mikesell <lesmikesell at gmail.com>

Ian Forde wrote:
> On Sat, 2009-02-21 at 17:24 -0600, Les Mikesell wrote:
>> Ian Forde wrote:
>>> Might not be a bad idea to see how they're able to use
>>> mdadm to detect and autosync drives.  I don't *ever* want to go through
>>> something like:
>>>
>>> http://kev.coolcavemen.com/2008/07/heroic-journey-to-raid-5-data-recovery/
>>>
>>> Not when a little planning can help me skip it... ;)
>> If you are really concerned about data recovery and can chunk up your 
>> filesystem mount points so things fit on a single disk (usually not too 
>> hard with 1 or 1.5 TB drives available now) just use software raid1 
>> since you can simply mount any single disk from it and access the files. 
>>   It becomes much more difficult with other raid levels or multi-disk lvm.
> 
> My point is that at home, I'd rather do network mounts to a fileserver
> utilizing HW RAID.  At work, I'd rather use HW RAID with hot-swap disks.
> This way, there's are no hoops to go through.  Time is a more important
> resource to me... SW RAID is a path that I went down well over a decade
> ago in Solaris (DiskSuite and Veritas VM), followed by Linux mdadm.  If
> you've ever had to do a Veritas encapsulated boot disk recovery, you'll
> know why I'd rather never go down that road *ever again*... ;)

Yes, but raid1 in software has none of those problems, since as far as 
the boot loader is concerned, you are booting from a single drive.  And 
there is a trade-off in complexity, since sw raid works the same on 
Linux across different hardware and you need to round up different 
vendors instructions and utilities for hardware raid - and have a backup 
controller around for recovery.

-- 
   Les Mikesell
    lesmikesell at gmail.com