On mercredi 19 mai 2010, MRK wrote: > On 05/18/2010 04:06 AM, Neil Brown wrote: > > However if --monitor gets to check the array between the above to events, > > it will first see that the working drive is now faulty, so it reports a > > failure, and then see that the faulty device isn't faulty any more and in > > fact isn't even there. The "isn't event there" bit doesn't register and > > it treats it as 'SpareActive'. > > > > I should fix that. > > However in one case the two events are not detected in the same round: > > Apr 12 20:10:02 phobos mdadm[3157]: Fail event detected on md device > /dev/md2, component device /dev/sdf1 > Apr 12 20:11:02 phobos mdadm[3157]: SpareActive event detected on md device > /dev/md2, component device /dev/sdf1 > > > 1 minute passes between the two entries. I suppose that's the mdadm > daemon polling time. > > In the other case all the entries are at the same time > > Apr 13 08:00:02 phobos mdadm[3157]: Fail event detected on md device > /dev/md2, component device /dev/sdd1 > Apr 13 08:00:02 phobos mdadm[3157]: SpareActive event detected on md device > /dev/md2, component device /dev/sdd1 > Apr 13 08:00:02 phobos last message repeated 7 times > [...many times that messages..] > > > ...plus, in this second case the SpareActive triggers a lot of times > within that same second (Pierre you cut it short, but are all the "many > times that messages" all at the exact same time or they span a few > seconds?) Well I was probably tired when I tried to filter the log for the bug report. It seems that this 'last message repeated 7 times' is for the: Apr 13 08:00:02 phobos kernel: [5814019.208017] nfsd: non-standard errno: 5 not for the: Apr 13 08:00:02 phobos mdadm[3157]: SpareActive event detected on md device /dev/md2, component device /dev/sdd1 I looked into my log and can't find something else. Sorry, sorry, sorry if this led you to false conclusions. > It looks to me like some kind of usb failure where the USB connection or > USB bridge momentarily fails then immediately gets re-detected and > re-added to the system. But since there are no usb entries in dmesg, > that would also be an issue of the usb driver. Could the problem also be > a mixture with some unwise udev triggers of Debian, maybe somehow > causing the auto-re-add of the drive to the RAID? > > Pierre: > - can you post your mdadm.conf? Sure, but I am not sure it will be useful: $ cat /etc/mdadm/mdadm.conf # mdadm.conf # # Please refer to mdadm.conf(5) for information about this file. # # by default, scan all partitions (/proc/partitions) for MD superblocks. # alternatively, specify devices to scan, using wildcards if desired. DEVICE partitions # auto-create devices with Debian standard permissions CREATE owner=root group=disk mode=0660 auto=yes # automatically tag new arrays as belonging to the local system HOMEHOST <system> # instruct the monitoring daemon where to send mail alerts MAILADDR root # definitions of existing MD arrays ARRAY /dev/md0 level=raid1 num-devices=2 UUID=13f4fdef:db0bd815:77e02d4f:1bda00b4 ARRAY /dev/md1 level=raid1 num-devices=2 UUID=4a120782:2ed3053c:e99784b3:b8e5f7bf ARRAY /dev/md4 level=raid1 num-devices=2 UUID=b3c7212a:e95c5081:24bf28c1:396de87f ARRAY /dev/md2 level=raid10 num-devices=4 UUID=b34f4192:f823df58:24bf28c1:396de87f ARRAY /dev/md3 level=raid5 num-devices=3 UUID=e1f30f82:0999431b:24bf28c1:396de87f > - USB is not good for RAID imho. Many times in my life I saw problems > with USB/SATA bridges where the drive would get disconnected on high I/O > activity and then reconnected after a few seconds. Anyway, readding it > to the RAID shouldn't have happened. Also in my case there were "usb" > entries in dmesg. Well, that is what I discover: USB and RAID is not currently fine (hum, on Debian stable, not sure, we can say 'currently', kernel is: $ uname -a Linux phobos 2.6.26-2-686 #1 SMP Tue Mar 9 17:35:51 UTC 2010 i686 GNU/Linux $ ). Anyway, it would be a great feature if USB can be used for a RAID setup, at least for end users (actually, I am using in my setup, a "special" layout for the using of RAID on several heterogeneous drives that I described here: http://www.linuxconfig.org/prouhd-raid-for-the-end-user ) Thanks for your help and regards. -- Pierre Vignéras -- 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
