Hi all, I've got an HP Microserver running FreeNAS with 5 * 2 TB consumer grade drives in RAIDZ2 mode. One of these drives became flaky. I was getting lots of checksum errors and ATA timeouts, leading to poor performance and long pauses. I cold swapped the flaky drive for another unit, and this is where I am now: Immediately after the replacement, another disk is now exhibiting exactly the same flakiness. Code: [root@freenas ~]# zpool status pool: bucket state: DEGRADED status: One or more devices could not be opened. Sufficient replicas exist for the pool to continue functioning in a degraded state. action: Attach the missing device and online it using 'zpool online'. see: http://illumos.org/msg/ZFS-8000-2Q scan: scrub in progress since Sun May 3 00:00:05 2015 4.83T scanned out of 5.92T at 24.5M/s, 12h56m to go 436M repaired, 81.61% done config: NAME STATE READ WRITE CKSUM bucket DEGRADED 0 0 0 raidz2-0 DEGRADED 0 0 0 gptid/4d86db8d-447f-11e3-9669-3cd92b0cfbd1 ONLINE 0 0 0 gptid/4ed362e1-447f-11e3-9669-3cd92b0cfbd1 ONLINE 0 0 70 (repairing) 8093132496243193286 UNAVAIL 0 0 0 was /dev/gptid/503868c4-447f-11e3-9669-3cd92b0cf bd1 gptid/512fb8d7-447f-11e3-9669-3cd92b0cfbd1 ONLINE 0 0 0 gptid/52ae9659-447f-11e3-9669-3cd92b0cfbd1 ONLINE 0 0 0 errors: No known data errors The first problem is that I can't utilise the new drive. Code: [root@freenas ~]# zpool replace bucket 8093132496243193286 ada2 cannot replace 8093132496243193286 with ada2: no such pool or dataset This worked OK on my other, almost identical unit, so I presume it's barfing because the other disk is being repaired. I've got about 3.5TB of data on this machine, and I'm trying to rsync it off ASAP, but with the ATA timeouts, it's running like a one legged dog, about 4Mbytes/sec, so it'll take about 2 weeks to finish. My current thinking is one of two alternatives: 1. Don't touch it. Leave it to limp along for 2 weeks and hope no other drives fail. 2. zpool remove the sick drive, and hope that this will bring the volume up to speed so I can whip everything off quickly. Can I get thoughts on this?