At 08:47 19-7-2002 +0200, Simon Matter wrote:
> I'm planning to use RAID 0+1 with XFS on kernel 2.4.18 (or 2.4.19 if
> by the time our disks come in). If there's any other good patches that
> recommend for a server, let me know - I'm currently in the habit of running
> mostly vanilla kernels on my servers (except for XFS of course ;).
I believe there are some NFS patches floating around which some people
recommend. It might be worth checking those out.
Now, another idea comes in because you want to be able to expand
existing arrays. I don't recommend LVM (LVM,EVMS,...) at the moment
because it makes things more complicated and it isn't worth it if you
only want to expand filesystems later by adding more disks. I recommend
using a linear 'RAID' on top of the RAID1 volumes. To expand later, you
may just create another RAID1 volume, append it to the linear array
while it is stopped and then grow the XFS filesystem on it. WARNING: I
have not tested linear arrays, if it works like the other RAID types, it
should be okay.
I like the theory but someone needs to prove it and let us know.
Normally you would need a abstraction layer like lvm for other raid levels
to make this work.
The linear option does kill performance to that of single disk and you
don't get the added write speed of the extra spindles. The read speed could
be up to twice the speed of single disk.
It might just be your lucky day, if you only knew.