[Dirvish] slow file transfers

[Dave Howorth]

Paul Slootman wrote:
> 3ware, there's your problem...

> After struggling for a couple of months, I wiped it all, reconfigured
> the 3ware controllers to just present 24 JBOD disks, and configured the
> raid under linux with md.  That performed a hell of a lot better.

Hmm, I went with the 3ware because a previous generation machine worked
reliably with them and I had zero experience of md so was reluctant to
trust it with my backups. Maybe I should reconsider that now.

> Also we've given up on reiserfs in the last couple of years, it's never
> really been stable with 2.6 kernels (on 2.4 kernels we never had
> problems). We're now happy with ext4, although I'm experimenting with
> btrfs and besides a number of crashes when I was experimenting with
> snapshots (and not really understanding what I was doing ;-) that works
> quite well as well.

I've used reiserfs extensively and never had any trouble. I went with
xfs on the new server for the data RAID but I'm not impressed so far. We
have many millions of fairly small files and reiser seems to deal with
them much better. xfs seems to be much less efficient in use of space,
for example.

btrfs looks nice but I think it's still too experimental for me.

Cheers, Dave