[Box Backup] userland RAID 5 vs RAID 1 consideration

Garry Glendown boxbackup@fluffy.co.uk
Tue, 21 Sep 2004 23:27:29 +0200


Tomasz Nowak wrote:
> 1. Storage performance is rather not the case on backup
>    machine; RAID 1 would perfectly do the job.
> 2. Reliability of RAID 1 is just the same as RAID 5.
> 3. Each RAID 1 array is 33% cheaper then RAID 5 array.

It is? 250G of RAID1 storage cost you 500G of raw storage, whereas 250G 
of RAID5 is only 375G of raw storage ... or other way around, two 250G 
HDs give you a total of 250G RAID1, three 250G HDs give you 500G of 
RAID5 ... for performance, I/O might be slightly better for RAID5, 
though CPU load is probably slightly higher ...

-gg