Hi, The configuration is: Perc H200 controller configured with no RAID (mpt2sas driver), 2 SATA disks (sda and sdb), Linux MD Sofware RAID1 (md0), stock Linux 2.6.35.7 kernel. I hotunplug the second (sdb) disk, and the result is: . as expected, I can read sda device, . as expected, any read to sdb device fails, . unexpectedly, any read to md0 never returns. No oops or thing like that in the kernel log. I did not try the same with other kernel releases. 2.6.32.24 kernel worked fine. Neil Brown asked for /proc/sysrq-trigger ouput, and concluded that the problem is related to 'fw_event0'. See his answer bellow. Regards, Hubert Tonneau Neil Brown wrote: > > The fw_event0 process is interesting. > It seems to be hung trying to 'sync' the drive that has just been pulled. > If that is somehow causing some IO request from the md/raid1 to be delayed > then that would certainly hang the array. > > There is a section in the middle of the trace which is missing - presumably > the sysrq-trigger output overflowed a buffer - that isn't uncommon. > > So I cannot see all the timing clearly. > How long after pulling the drive was this trace taken? > > I suspect that you need to post this to linux-scsi@xxxxxxxxxxxxxxx > and ask about that fw_event0 thread - whether that should happen, whether it > has been fixed, and whether it could delay pending IO requests. > > NeilBrown -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
