RE: storage server & scalability
> Issue 1:
> It seems obvious that SCSI is the way to go. However, because of the
> simple fact that (S)ATA provides much more capacity (and is far less
> expensive) we would like to know what you think of using SATA drives
> in a storage server. And what RAID level would be a good choice? It
> may be good to know that we will setup 2 identical storage servers,
> one as a hot-spare, which syncs it's disks with DRBD from the main
> storage server. Off-course we will be using heartbeat to take over the
> ip on the hot-spare once the main storage becomes unavailable.
It would be worth knowing, filesystem corruption will be copied over from
your "master" with DRBD to the hot-spare (if it ever occurs). It has
happened to us previously and took quite sometime to recover.
Our current setup (very similar to what you are talking about, and almost
identical) is SATA disks using RAID6.
> Issue 2:
> Another question which remains unanswered for us is how one would
> scale storage. For example, if we setup a storage server with RAID 5
> or RAID 6, how can we extend the RAID array with more capacity,
> without losing data? Would it be as simple as plugging in another disk
> at the array?
You should be able to extend the storage space by adding drives without
losing data (Software you would just 'hot add' the new partition to the
array; and with Hardware just add the new disk to the array). It will be
slightly different depending on whether you are using hardware or software
I hope this helps a little bit.