On Sun, 29 Jul 2012, David Boyes wrote: > Since we have ample data from multiple sources that this DOES NOT operate > reliably, the original question still stands.
Would you mind sharing some of this ample data? Are this all cases where dasdfmt complains about other users after "udevadm settle" returned? When this fails do you find messages from udev in /var/log/messages? Regards, Sebastian > How can we reliably block until a I/O subsystem operation is fully and > reliably known to be complete? > > Tracing the udevadm process seems to show some /by-uuid processing that is > failing due uuids being the same -- is there something in the udev device > activation that somehow relies on a unique UUID? If so, that would explain > why it sometimes works and sometimes doesn't (if the device you're trying to > activate is on a different physical disk, you'd win here; if it's on the same > physical disk, you'd lose, or at least have udev try alternative code paths > to get a unique device node created and assigned. Using TDISK or VDISK for > the test case would mislead, as at least tdisk could be on different physical > volumes. I can send you a log from the trace if that would help you. > > In any case, I think Mike's question is a good one: if chccwdev needs a > 'udevadm settle' to operate correctly, why isn't it doing it itself? It seems > like we should be able to rely on chccwdev operations being atomic. > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO LINUX-390 or visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > ---------------------------------------------------------------------- > For more information on Linux on System z, visit > http://wiki.linuxvm.org/ > > ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
