(apologies if this is a repost - sent 3 attempts into the vger void already) In doing some tests with an 8-port Supermicro/Marvell-based SATA controller (works fine so far) and some Hitachi 3TB disks, I've run into an odd problem. One of the disks failed in burn-in, so the RAID5 went into degraded mode. In replacing the failed disk, I managed to bugger it up; not so awful since it's a test rig and I needed to create 2 smaller arrays for some testing. In trying to do that, I was able to create the first 4-disk RAID5 fine and it's now initializing, but the second fails with the following error: $ mdadm --create --verbose /dev/md1 --level=5 --raid-devices=4 /dev/sd[fghi]1 mdadm: layout defaults to left-symmetric mdadm: layout defaults to left-symmetric mdadm: chunk size defaults to 512K mdadm: /dev/sdf1 appears to be part of a raid array: level=raid5 devices=7 ctime=Fri Sep 30 17:47:19 2011 mdadm: layout defaults to left-symmetric mdadm: super1.x cannot open /dev/sdg1: Device or resource busy mdadm: /dev/sdg1 is not suitable for this array. mdadm: layout defaults to left-symmetric mdadm: /dev/sdh1 appears to be part of a raid array: level=raid5 devices=7 ctime=Fri Sep 30 17:47:19 2011 mdadm: layout defaults to left-symmetric mdadm: create aborted mdstat implies that one of the disks still belongs to the previous RAID5: $ cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md0 : active raid5 sde1[4] sdd1[2] sdc1[1] sdb1[0] 6442438656 blocks super 1.2 level 5, 512k chunk, algorithm 2 [4/3] [UUU_] [========>............] recovery = 40.1% (861382528/2147479552) finish=292.9min speed=73167K/sec md_d0 : inactive sdg1[5](S) 2147480704 blocks unused devices: <none> but I can't seem to convince md_d0 to surrender this device. This behavior survives a reboot. One wrinkle is that the original RAID was made with the default mdadm from Ubuntu 10.04.3 (2.6.7.1) and the smaller RAID5 above was created with the latest mdadm (v3.2.2). What do I have to do to free this device? TIA, -- Harry Mangalam - Research Computing, OIT, Rm 225 MSTB, UC Irvine [ZOT 2225] / 92697 Google Voice Multiplexer: (949) 478-4487 MSTB Lat/Long: (33.642025,-117.844414) (paste into Google Maps) -- This signature has been OCCUPIED! -- 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