RE: RAID

["Paul Sims" <nospam [at] lombard.co.uk>]

How do you equate RAID with backup solutions ? OK, full RAID 5 (or RAID 10 
for the nervous) reduces the impact of a single disk outage, but a coherent 
& comprehensive backup strategy must be maintained unless you want to send 
your valuable data to the great bit-bucket in the sky.

A customer of ours backed up his RAID 5 systems to DLT nightly, tapes 
stored in a safe. Then had a near-simultaneous 2-disk failure. Result, 
total loss of everything, requiring the array to be rebuilt & the system 
brought back to life before the data could be restored.

View RAID as a high throughput (RAID 0,1) or high availability (RAID 5 or 
RAID 10 - mirrored RAID 5) hard disk, not a data security solution or it 
will come back & bite you badly. And go for a hardware RAID solution with 
hot-swap, software RAID is IMHO a bad thing. Learn what RAID is and does, 
and the benefits & drawbacks (for instance 4 seperate r/w operations to 
write a single sector of data in RAID 5). Compaq do a very good system with 
SmartArray, the Mylex cards are also excellent, go for a solution that 
stores the RAID map on the disks rather than a dumb system which leaves the 
map on a config sheet which inevitably gets lost.

On Thursday, March 02, 2000 4:34 PM, Steve Tickle 
[SMTP:s.tickle [at] quarndon.co.uk] wrote:
> In the course of me exploring linux as an alternative to our M$ based
> systems here I need to address backing up of data. We currently use a
> system that backs up in real time (sort of) to an Iomega Zip (or Jazz)
> drive. We'd like to continue in this vein as periodic back ups are a pain 
> in the a*rse.
> It occurred to me that as the amount of data we want to back up could
> increase dramatically we could consider RAID.
> My question is, what software RAID systems exist for linux, what's 
involved
> and how much of a pain are they to set up?
>
> Thanks in advance
>
> Steve
>
>
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"WorldSecure Server <lombard.co.uk>" made the following
 annotations on 03/03/00 09:25:39
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