Bug #1928
open
zfs send/receive kills COMSTAR
0%
Description
We're running COMSTAR on oi_151a with the iSCSI LUNs backed by ZFS volumes. Whenever we try to back up the server, doing a zfs send/receive to the backup server, the iSCSI clients get timeout errors from the COMSTAR server. We set the tunables iscsi_sess_logging, iscsi_login_logging, idm_conn_logging, and idm_sm_logging to 1 while performing the latest zfs send/receive.
I'm including a copy of /tmp/messages with the result of the above tunables set to 1.
Files
Updated by Dan McDonald over 9 years ago
Have you tried running "lockstat sleep 10" (or some longer snapshot of time) during the time it's hanging? I don't understand the interactions between COMSTAR and zvols as well as I'd like, but I seem to recall that COMSTAR does a lot of direct-zvol access (perhaps more than it should), and you may be seeing lock contention there.
Updated by The Written Word Inc over 9 years ago
Haven't tried that. Will initiate a backup tonight and try. Thanks.
Updated by The Written Word Inc about 9 years ago
Attaching the result of "lockstat sleep 5" when we were performing a zfs send/receive. The iSCSI initiator started failing all clients.