What failure are you getting? I assume a read error. md will fail a drive when it gets a read error from the drive. It is "normal" to have a read error once in a while, but more than 1 a year may indicate a drive going bad. I test my drives with this command: dd if=/dev/hdi of=/dev/null bs=64k You may look into using "smartd". It monitors and tests disks for problems. However, my dd test finds them first. smartd has never told me anything useful, but my drives are old, and are not smart enough for smartd. Guy -----Original Message----- From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid-owner@xxxxxxxxxxxxxxx] On Behalf Of Michael Stumpf Sent: Wednesday, December 08, 2004 4:03 PM To: linux-raid@xxxxxxxxxxxxxxx Subject: 2 drive dropout (and raid 5), simultaneous, after 3 years I've got a an LVM cobbled together of 2 RAID-5 md's. For the longest time I was running with 3 promise cards and surviving everything including the occasional drive failure, then suddenly I had double drive dropouts and the array would go into a degraded state. 10 drives in the system, Linux 2.4.22, Slackware 9, mdadm v1.2.0 (13 mar 2003) I started to diagnose; fdisk -l /dev/hdi returned nothing for the two failed drives, but "dmesg" reports that the drives are happy, and that the md would have been automounted if not for a mismatch on the event counters (of the 2 failed drives). I assumed that this had something to do with my semi-nonstandard application of a zillion (3) promise cards in 1 system, but I never had this problem before. I ripped out the promise cards and stuck in 3ware 5700s, cleaning it up a bit and also putting a single drive per ATA channel. Two weeks later, the same problem crops up again. The "problematic" drives are even mixed; 1 is WD, 1 is Maxtor (both 120gig). Is this a known bug in 2.4.22 or mdadm 1.2.0? Suggestions? -------------------------------------------- My mailbox is spam-free with ChoiceMail, the leader in personal and corporate anti-spam solutions. Download your free copy of ChoiceMail from www.choicemailfree.com - 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 - 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