It's my understanding, that an array running with [UU_] is degraded and there is a disk problem. I have been trying to create a RAID array using this command: mdadm --create --verbose /dev/md0 --level=5 --raid-devices=3 /dev/sdb1 /dev/sdc1 /dev/sdd1 However, once it create it, it get this in /proc/mdstat: Personalities : [raid6] [raid5] [raid4] md0 : active raid5 sdd1[3] sdc1[1] sdb1[0] 3906764800 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/2] [UU_] [>....................] recovery = 0.1% (2611780/1953382400) finish=1737.7min speed=18709K/sec bitmap: 0/15 pages [0KB], 65536KB chunk I have done the following to "fix" the drive: 1. Smartmontools smartctl long and short tests. All passed. 2. Zeroed the first 1GB of the drive (overkill, I know I could just do the first 512) with dd if=/dev/zero of=/dev/sdb count=250000 bs=4k 3. Re-partitioned the drive. 4. Re-create. No joy. Then, I swapped this hard drive out for another drive. I am still getting [UU_]. Thoughts? -- Michael Munger, dCAP, MCPS, MCNPS, MBSS High Powered Help, Inc. Microsoft Certified Professional Microsoft Certified Small Business Specialist Digium Certified Asterisk Professional michael@xxxxxxxxxxxxxxxxxxx -- Michael Munger, dCAP, MCPS, MCNPS, MBSS High Powered Help, Inc. Microsoft Certified Professional Microsoft Certified Small Business Specialist Digium Certified Asterisk Professional michael@xxxxxxxxxxxxxxxxxxx -- 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