[Ukfreebsd] knock knock

Pete French pete at twisted.org.uk
Wed Mar 24 19:03:04 GMT 2010


> Well now it's back I'd like to ask if anyone is using 7.x/8 with an
> iSCSI SAN in a production environment and if so how it runs.

I haven't used it in production 9too flaky at the moment) but I
did spend a while testing the iSCSI initiator and discussing it
with Danny, and applying various patches. When it works it
works very well, but the problem for me was the behaviour when
the target goes down. Instead of timing out and eventually
reportying an error it seems to just lock up (preseumably when
the queue of write requests gets too full).

I have ended up using ggated for remote drives, which does nicely
drop the drive when things stop woring. It seems somewhat sensetive to
this in combination with gmirror though. Gmirror is far too eager to
drop part of a mirror when writes fail - and they can fail just because
the far end is slow! Try resilering from a local fast drive to a very slow
drive (ggated over a network will do).

Having said that, we run a pair of machines as a simple hand-made
cluster using ggated and gmirror very successfully. I would prefer to
be using iSCSI and ZFS though. ZFS doesnt co-operate well with ggated
either! Or it didnt last time I tested anyway...

-pete.



More information about the Ukfreebsd mailing list