Hi There! I have two scsi disk with idendical partitiontables (see below) installed on a SCA HotSwap enable Fujitsu-Siemens server. As a test I've removed one of the disks and the /dev/md0 went in degraded mode as expected. (se snip from /var/log/messages below) ... but what about /dev/md1 which also have a partition on /dev/sdb which I've removed????? Nothing. And when I check "/proc/mdstat" the /dev/md1 seames to be running without error.... strange. Note: --------- Later investigation have show, that /dev/md1 would go into degraded mode if I've coppyed some data to it. (See fstab below). Problem is that I have intended /dev/md1 as a partition for swap. This is nesseray to really have a High Avalible (HA) system. --------- The real problems start when I re-insert the /dev/sda. The systems stops all activity on HD after some errore in the /var/log/messages and a hard reset is only option. The system can however boot up. A look at /proc/mdstat shows that the /dev/md0 (still) and /dev/md1 is now correctly set as working in degraded mode. If I now run "raidhotadd /dev/md0 /dev/sdb1" and "raidhotadd /dev/md0 /dev/sdb1" evething rebuilts nicesly. Later experiments have shown that I have to power off the system, insert the disk and boot. This is however not the intended use of a HotSwap system. BTW SCSI card: 53c1010 Ultra3 SCSI Adapter from Symbios uname -a => "Linux ABI1 2.4.18-4GB #1 Wed Sep 18 16:33:24 CEST 2002 i686 SuSE 8.0 Raid" with RAID1, jbd and ext3 compiled into the kernel. RAID: raidtools-0.90-349 --------------- snip /var/log/messages ------- Sep 19 14:25:57 ABI1 kernel: SCSI disk error : host 0 channel 0 id 1 lun 0 return code = 100ff Sep 19 14:25:57 ABI1 kernel: I/O error: dev 08:11, sector 37992 Sep 19 14:25:57 ABI1 kernel: raid1: Disk failure on sdb1, disabling device. Sep 19 14:25:57 ABI1 kernel: Operation continuing on 1 devices Sep 19 14:25:57 ABI1 kernel: md: recovery thread got woken up ... Sep 19 14:25:57 ABI1 kernel: md: updating md0 RAID superblock on device Sep 19 14:25:57 ABI1 kernel: md: (skipping faulty sdb1 ) Sep 19 14:25:57 ABI1 kernel: md: sda1 [events: 00000036]<6>(write) sda1's sb offset: 6816640 Sep 19 14:25:57 ABI1 kernel: SCSI disk error : host 0 channel 0 id 1 lun 0 return code = 100ff Sep 19 14:25:57 ABI1 kernel: I/O error: dev 08:11, sector 38000 Sep 19 14:25:58 ABI1 kernel: md0: no spare disk to reconstruct array! -- continuing in degraded mode Sep 19 14:25:58 ABI1 kernel: md: recovery thread finished ... --------------- /var/log/messages snip ------- ----------------- output of "cat /proc/mdstat" before failer start -------------------- Personalities : [raid0] [raid1] [raid5] read_ahead 1024 sectors md0 : active raid1 sdb1[1] sda1[0] 6816640 blocks [2/2] [UU] md1 : active raid1 sdb2[1] sda2[0] 2107328 blocks [2/2] [UU] ----------------- output of "cat /proc/mdstat" before failer end -------------------- ----------------- output of "cat /proc/mdstat" AFTER failer start-------------------- Personalities : [raid0] [raid1] [raid5] read_ahead 1024 sectors md0 : active raid1 sdb1[1](F) sda1[0] 6816640 blocks [2/1] [U_] md1 : active raid1 sdb2[1] sda2[0] 2107328 blocks [2/2] [UU] unused devices: <none> ----------------- output of "cat /proc/mdstat" before AFTER end -------------------- ----------------- output of "sfdisk -cl" start -------------------- Disk /dev/sda: 8715 cylinders, 64 heads, 32 sectors/track Units = cylinders of 1048576 bytes, blocks of 1024 bytes, counting from 0 Device Boot Start End #cyls #blocks Id System /dev/sda1 0+ 6656 6657- 6816752 fd Linux raid autodetect /dev/sda2 6657 8714 2058 2107392 fd Linux raid autodetect /dev/sda3 0 - 0 0 0 Empty /dev/sda4 0 - 0 0 0 Empty Disk /dev/sdb: 8715 cylinders, 64 heads, 32 sectors/track Units = cylinders of 1048576 bytes, blocks of 1024 bytes, counting from 0 Device Boot Start End #cyls #blocks Id System /dev/sdb1 0+ 6656 6657- 6816752 fd Linux raid autodetect /dev/sdb2 6657 8714 2058 2107392 fd Linux raid autodetect /dev/sdb3 0 - 0 0 0 Empty /dev/sdb4 0 - 0 0 0 Empty ----------------- output of "sfdisk -cl" end-------------------- ------ raidtab start ------------ raiddev /dev/md0 raid-level 1 nr-raid-disks 2 nr-spare-disks 0 persistent-superblock 1 chunk-size 4 device /dev/sda1 raid-disk 0 device /dev/sdb1 raid-disk 1 raiddev /dev/md1 raid-level 1 nr-raid-disks 2 nr-spare-disks 0 persistent-superblock 1 chunk-size 4 device /dev/sda2 raid-disk 0 device /dev/sdb2 raid-disk 1 ------ raidtab end ------------ ----------- /etc/fstab start ----------- /dev/md0 / ext3 defaults 1 2 /dev/md1 /data ext3 defaults 1 2 devpts /dev/pts devpts defaults 0 0 /dev/cdrom /media/cdrom auto ro,noauto,user,exec 0 0 /dev/dvd /media/dvd auto ro,noauto,user,exec 0 0 /dev/fd0 /media/floppy auto noauto,user,sync 0 0 usbdevfs /proc/bus/usb usbdevfs noauto 0 0 proc /proc proc defaults 0 0 ----------- /etc/fstab end ----------- PS.. 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