Hello, I did test IO, and upon issuing IO, then md correctly detected the failure and began a rebuild. However, my opinion is that this is inadequate and actually, I do not believe this is correct behavior. As I recall from prior experiences with md, md would initiate a rebuild based on drive removal only as well, even without any pending IO. I would appreciate some further feedback as to this behavior. Thanks! -Tommy On Mon, Jun 6, 2011 at 2:25 PM, CoolCold <coolthecold@xxxxxxxxx> wrote: > On Mon, Jun 6, 2011 at 10:20 PM, fibreraid@xxxxxxxxx > <fibreraid@xxxxxxxxx> wrote: >> Hello, >> >> I am running Linux kernel 2.6.38 64-bit version with mdadm 3.2.1. The >> server hardware has dual socket Westmere CPUs (4 cores each), 24 GB of >> RAM, and 24 hard drives connected via SAS. >> >> I create an md0 array with 23 active drives, 1 hot-spare, RAID 5, and >> 64K chunk. After synchronization is complete, I have: >> >> root::~# cat /proc/mdstat >> Personalities : [raid6] [raid5] [raid4] >> md0 : active raid5 sdf1[23](S) sdi1[22] sdh1[21] sdg1[20] sde1[19] >> sdd1[18] sdc1[17] sdo1[16] sdn1[15] sdq1[14] sdp1[13] sdr1[12] >> sdm1[11] sdl1[10] sdk1[9] sdj1[8] sdv1[7] sdu1[6] sdt1[5] sds1[4] >> sdy1[3] sdx1[2] sdb1[1] sdw1[0] >> 2149005056 blocks super 1.2 level 5, 64k chunk, algorithm 2 >> [23/23] [UUUUUUUUUUUUUUUUUUUUUUU] >> >> Then I remove an active drive from the system by unplugging it. udev >> catches the event, and fdisk -l reports one less drive. In this case, >> I remove /dev/sdv. >> >> However, /proc/mdstat remains unchanged. It's as if md has no idea >> that the drive disappeared. I would expect md at this point to have >> detected the removal, and to have automatically kicked-off a resync >> using the included hot-spare. But this does not occur. >> >> If I then run mdadm -R /dev/md0, in an attempt to "wake up" md, then >> md does realize the change, and does start the resyncing. > I guess md realizes there is no drive when write/read error occurs, > which gonna happen pretty soon if array is in usage, can you set some > dd reading and then remove drive? > >> >> I do not believe this is normal behavior. Can you advise? >> >> Thank you! >> -Tommy >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-raid" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > > > > -- > Best regards, > [COOLCOLD-RIPN] > -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
