Re: Raid level 5

[Jean-Eric Cuendet <jec rptec ch>]

At 05:14 3/31/2004, you wrote:

>>I'm thinking about setting up a software raid level 5.
>>Is it possible to start with 3 HDs and then later add more?
>>I mean, without loosing the data on the first 3 HDs.


> Yes, on most *good* hardware RAID cards and also (I think) on Linux
> software RAID.

Arg....
On *very good* hardware cards, perhaps....
But on software RAID, no, you can't.
With RAID 5, data is interleaved on each disks, so adding a new one and 
rebuilding everything, is not easy.
With soft RAID 5, the best to do is backing up filesystem, rebuilding 
the RAID5 from scratch and reinstalling the backup.

That said, the soft RAID (1 or 5) is *very* good in Linux 2.4.
Thanks to kernel developers!
-jec