Am 26.03.2015 um 16:02 schrieb Kevin Wolf: > Am 26.03.2015 um 15:54 hat Peter Lieven geschrieben: >> Hi Block people, >> >> we recently observed some strange I/O stalls on some vServers. I suspect a >> bug in the target and >> already added some debugging output to libiscsi that could have helped to >> track the issue. >> >> However, to enable this debugging I would need to call >> >> iscsi_set_log_level >> >> during runtime from the hmp or qmp. >> >> I wonder what would be the best way to do this and/or if it would be >> interesting to have a generic >> way to tell a block backend to enter debugging whereas I would leave it up >> to the backend driver >> what exactly that means? >> >> Other option would be to set an enviroment variable during runtime. But as >> far as I know thats >> not possible. > I think debugging should be controlled with driver-specific options to > bdrv_open(). For changing the debugging options at runtime, we'd need to > provide a way to directly call bdrv_reopen() from the monitor. > > Before this can work, we need some more infrastructure work that even > introduces the concept of QDict *options to bdrv_reopen(). I have > patches to do this, but even though that branch mostly works, it is > still rather messy and not in a mergable state. If you're interested > anyway, it's the blockdev branch in my tree. > > For your immediate case, you'll probably want a downstream ad-hoc hack > rather than waiting for the real thing.
That sounds like the best approach. Would it make sense to already introduce a debug option in the options and honour it at least in bdrv_open? Thank you, Peter
