[Sussex] AMD Sempron Chips and BIG backups

[Jon Fautley]

Alan Pope wrote:
> On 12/12/05, Ronan Chilvers <ronan at thelittledot.com> wrote:
> 
>>I'd be using Debian Sarge and the machine would be working as a file
>>server with a few big drives in a software raid array.  The design
> 
> 
> Heheh@ big drives. One mans "big" is another mans "tiny".

Agreed - 100GB? Pah... ;)

A quick tally of storage that I really should backup stands at ~1TB. 
That's just at home - I'm not even going to mention work ;)

> 
>>department here is managing to generate increasingly frightening file
>>sizes which is using up disk space at an alarming rate.  I was thinking
>>of shelling out on some big SATA (or even IDE) drives and chaining them
>>into a raid5 or maybe raid10 (don't know if software raid supports
>>raid10 but I think it does).
>>
> 
> 
> Yeah, I've just bought 8 off 200GB SATA disks for home backups myself.
> Will raid them as mirrored rather than RAID 5 though.

Remember - you can't just stick lots of disks in an enclosure if they're 
not designed for it.

This is especially true with newer SATA disks, as the access times, and 
drive speed, tends to cause a lot more 'bad' vibrations when they're in use.

OK, I'll try and be quick:

Hard Disk drives can handle high frequency vibrations without a care in 
the world, they're designed for it. However, they're not so accustomed 
to low frequency vibrations - the exact kind that a large number of 
disks creates :|

This is one of the reason SCSI disks are so expensive - they're designed 
to cope with LF vibrations generated when you put 3+ disks in one 
enclosure. That's also why you can get "SATA RAID" disks - they're 
designed for bulk use.

Just remember - sticking a large number of cheap disks in a single 
enclosure can cause problems - if this is a mission critical system, I 
would consider SCSI disks, or if price is an issue, SATA RAID disks.

> This can be done under linux with LVM I believe. I have not tried it
> myself but this link might be interesting to you.
> 
> http://www.tldp.org/HOWTO/LVM-HOWTO/snapshotintro.html

Ack. If you're going down this road, test, test, test and test some more 
before you deploy it :)

Jon
-- 
Jon Fautley <jfautley at redhat.com>     direct: +44 1483 739615
  Technical Account Manager            office: +44 1483 300169
  Red Hat UK                           mobile: +44 7841 558683
  10 Alan Turing Road, Surrey Research Park, Guildford GU2 7YF