[NTLUG:Discuss] Backup solutions

[David Stanaway]

If you are using disk storage, you need to think about what situations
you are backing up for? Hardware failure? Operator error?

How about a malicious attack or a fire?

Maybe I am biased, since I put 10TB of data to tape a week, but LTO3 is
fast and dense.  With compression of average data, you can get ~ 800GB
onto one tape, and it doesn't take that long to make a copy from your
backup disk cache to a second tape.


In smaller scenarios you could probably get by with just one tape drive
on your backup server (And one at your offsite location), LTO3 drives
are probably about 6g a pop, and the tapes depend on the quantity you
are getting, say $80 each.

If your data fits on DVD, that is an OK option too. In that case you may
want to look at system filesystems that support differential online
dumps.  XFS is a good example there, but there are others. The problem
with that solution though, is you need to handle the possibility that
one of your backups spans multiple dvds.  These days, I don't see DVD as
a realistic option for backups, as it is not practical to back up
everything on the system, as otherwise, you are just backing up a
subset, and chances are, one day, you will need to recover something
outside of the subset you cherry picked back when you set up your backup
infrastructure.

Fred James wrote:
> David Stanaway wrote:
> 
>> Leroy Tennison wrote:
>>  
>>
>>> I've been asked this twice recently.  My thinking is tape or CD/DVD with 
>>> the latter being preferable for small situations.  Are there other good 
>>> alternatives?
>>>    
>>>
>> LTO3 baby.
>>  
>>
> Tapes ares still hard to beat for long term, low cost, off line 
> storage.  But in our experience, moving between 3.5 and 5 GB of 
> compressed data each day (database is running around 25-30 GB 
> uncompressed at the moment), we have found hard drive space to be pretty 
> cheap and vary reliable for local, and near local, relatively short term 
> off line storage.  By short term storage, I mean that we keep a rotation 
> of backup data on disk, aging it out and replacing it in turn with the 
> latest set.  For added security, protection against disk failure can be 
> accomplished by redundant copies on different disk.  Hope this helps.
> Regards
> Fred James
> 
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