Re: Backups using RAID1

[Bill Davidsen <davidsen@tmr.com>]

Drew wrote:
>> If you don't care about location-based risks (eg fire), then I don't
>> see why you would bother removing the drives. Leaving disks in the
>> machine basically only protects you against 'oops' moments (rm -rf and
>> such like)., but not much else.
>>     
>
> In this instance location based risks (fire, earthquake) are a
> concern. My original idea when I started exploring backup ideas was
> something I could leave unattended to start when I went to bed and if
> for some reason I was forced to evacuate in the wee hours of the
> morning all I had to do was yank the drives from the server and leave.
>
> As far as oops moments, only the applications have direct access to
> files on disk. All user access to disks is via Samba and I've enabled
> the recycle bin vfs module.
>
>   
>> The advantage in RAID1 is that it makes a copy constantly, so it takes
>> no time to create the backup - using other methods (rsync, tape,
>> rdiff-backup) with a huge amount of data, this time can be
>> prohibitive.
>>     
>
> That was part of why I was looking at RAID for the backup. I've also
> had a few suggestions about getting an external eSATA drive and
> leaving it plugged in overnight. Just have a cron job do a nightly
> rsync or such and *if* I have to evacuate, hopefully rsync will be
> complete.
>
>   
If you are that paranoid about the backup, get two and use a different 
one each night. You can run a cron job to back stuff up (I've done it) 
every half hour or so, given three checks: (a) is the last one finished, 
(b) is the last modified time > 30 minutes (ie. is it done), and (c) has 
it been modified more recently than the last backup (touch a file at the 
end of backup).

Having dealt with both fire and earthquake, I doubt your wife will worry 
about the recordings, just getting the people and pets out, and whatever 
paperwork you have in your fireproof safe (in case time is tight).
>> Also, I'd say that plugging/unplugging disks would historically be a
>> problem, but SATA shouldn't be, IMO. Also, there are solutions
>> specifically designed for plugging/unplugging - which makes the point
>> moot - so you might consider one of those.
>>     
>
> My SATA controller supports hot plugging so I'm not worried there.
>
>
>   


-- 
Bill Davidsen <davidsen@tmr.com>
  "Woe unto the statesman who makes war without a reason that will still
  be valid when the war is over..." Otto von Bismark