On Sat, 8 Jan 2005, Guy Coates wrote: > On Sat, 8 Jan 2005, christophe varoqui wrote: > > > On Sat, 2005-01-08 at 14:53 +0000, Guy Coates wrote: > > > > > The filesystem is XFS. > > > > > > To trigger the problem I simply mount the filesystem and wait. There is no > > > IO apart from the filesystem journaling activity. > > > > > Not even the checkers ? > > Ok, it seems to be the TUR path checker. When I run the multipath command to create the initial device map I get the UNDERRUN error reported for each target. Jan 9 10:36:40 web-4-09 kernel: scsi(3:0:5) UNDERRUN status detected 0x15-0x800. Jan 9 10:36:40 web-4-09 kernel: scsi(3:0:5) UNDERRUN status detected 0x15-0x800. However, I can mount the multipath device and do sustained, error free IO to it, so long as multipathd is not running. If I start multipathd I start seeing errors within 35 minutes of starting the deamon. Jan 9 10:25:08 web-4-09 kernel: scsi(3): Found in Pending queue pid821520, State = 6., fcport state=4 jiffies=37d2967 Jan 9 10:25:08 web-4-09 kernel: scsi(3:0:6) qla2x00_done: did_error = 2, comp-scsi= 0x0-0x0. etc... <snip> If I use the readsector 0 path_checker, I still get the UNDERRUN errors on initial device map creation, but I don't get any further errors[1] after starting multipathd and it all works correctly. Guy [1] (The ghost paths report Device sdX not ready. as expected) -- Dr. Guy Coates, Informatics System Group The Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, UK Tel: +44 (0)1223 834244 ex 7199