multi TB storage

[Daniel Robitaille]

On Wed, Mar 24, 2010 at 8:31 PM, Christopher Chan
<christopher.chan at bradbury.edu.hk> wrote:
>
>>> That is kind of what I am looking for. I will be building something that
>>> will eventually take 36 disks and just wondered if anyone at all uses
>>> Ubuntu to any serious storage.
>>>
>>> I will be running a Windows 2008 guest to boot too while also doing the
>>> job of a file server, I am currently mulling over backup possibilities
>>> and whether to run hardware raid or software raid. Backup wise, I kind
>>> of need half hourly snapshot capabilities (can't have kids/teachers lose
>>> their last hour of work...) but it does not seem that that will be
>>> possible with Ubuntu or at least I have not heard anything in this
>>> regard. That requirement does not apply to the Windows 2008 guest.
>>>
>>
>> I use hardware Raid on that Dell server with a Dell PERC6/e card.  For
>
> Ho hum, that does not really say much. Are you going to use raid5 with
> 30 disks with spares? raid6? I am also planning to cut costs by using a
> 200USD or so hba or two and software raid to manage the lot versus
> getting something five times more expensive with just 512MB of bbu
> cache. I mean, if I am going to use raid10, why bother with a raid
> controller when the performance differences will be rather slight? If it
> were raid5/6 that will be used, then yeah, give me a raid controller
> with lots of cache.

The 15 drives in that external enclosure are RAID-6; I don't think I
have a spare disk in that one.  The 8 internal drives are a mixed bag
(due to historical reason and operational requirements): 4 of them in
one RAID-5 partition, 4 in individual RAID-0 partitions.


>
>> an simple way to setup a snapshot system in Ubuntu, you can use
>> rsnapshot from the Ubuntu repositories.
>>
>>
>
>
> Interesting. hard links and rsync eh? Do you think it can manage
> rotations of 2000 for data over 500GB in size?

I have used rsnapshot to deal with daily backups of filesystems in the
5TB range, in both Debian and Ubuntu.   It probably cannot deal with
30minutes snapshots like you wanted,  but for daily (once every night)
and weekly it works fine for me.


-- 
Daniel Robitaille