Ben Gollmer schrieb:
> Thanks for all your input.
> I'm going to stick with the Promise ATA-133 controllers, as they are only $30
> at www.newegg.com. Also I am using software RAID, the 3ware controllers that
> I looked at were hardware RAID only and too expensive - I'd rather have more
> storage space.
> I'm planning to use RAID 0+1 with XFS on kernel 2.4.18 (or 2.4.19 if it's out
> by the time our disks come in). If there's any other good patches that you'd
> 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 ;).
There are some IDE and software RAID related patches you may want to
use. I suggest looking at a recent RedHat kernel source RPM to get an
idea of what might be appropriate.
> Quick question for anyone with Linux software RAID experience: our RAID 0 will
> be composed of two RAID 1s, md0 and md1. if we decide we need more storage,
> is it easy to create another RAID 1 (md2) and add it to the stripe set? Or
> would that require something like LVM (or even a re-format)?
RAID 0+1 can be created in two different ways, but only one of them
performs well, the other way around the RAID performs _very_ bad. Create
a RAID0 on top of two RAID1 like this:
raid-level 0 <-- you may want to use 'linear' instead
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.
> Thanks again,