FreeNAS 8.2 extermely slow, one HDD could be broken

[grig]

Hello everybody,

I'm running FreeNAS-8.2.0-RELEASE-p1-x64 (r11950), on a Zotac mini-ITX mainboard, RAIDZ created out of 6 SATA HDDs.

The system boots up just fine and everything is reported as working except that any disk operation is very, very slow. A simple 'ls' of a directory containing 3 items takes almost 5 minutes to complete and 'cat'-ing a 1kb file takes twice as much.

I suspect that one of the disks has failed because I can periodically hear a spin-up sound. 'zpool status' reports everything ONLINE, no known data errors. How can I identify the failed disk without corrupting the data?

Thank you.

 

[jgreco]

More likely to be a failing drive. It may not be returning hard errors, and eventually succeeding in reading sectors.

Identify the list of disks (from "camcontrol devlist" or "dmesg" or whatever).

Reboot your system into singleuser mode.

For each disk device, do "dd if=/dev/mydiskdev of=/dev/null bs=1048576"

You can use control-T to see statistics while it runs. Most likely one drive will be going real slow. Possibly not right away! Sometimes a section of the platter becomes damaged or something like that. Anyways, if you let that run to completion for each of your disks, one of the disks should have what appears to be an anomaly as to its runtime, and/or may not complete running at all, and/or you use your ears and identify-it-by-sound.