[mythtv-users] Seagate confirms problems with 1.5TB Barracuda drives

[Martin Bene]

> I have one SD17 1.5TB, and I added it to a raid5 array, and
> it built in in the array just fine, and then kicked it out
> 3-4 hours later on a very odd looking error, and checking
> the disk for errors showed no errors.

> Turning off write-cache, and again rebuilding it into the
> array it has so far lasted 3-4 days without issues, so there
> appears to be something to the write cache issue.
> The error I got looked like the drive just did
> not finish its write and the driver timed it out.

The typical Seagate 1.5TB error looks like this:

ata2.00: cmd ea/00:00:00:00:00/00:00:00:00:00/a0 tag 0 cdb 0x0 data 0
         res 40/00:00:00:4f:c2/00:00:00:00:00/40 Emask 0x4 (timeout)

The failing command code is EA (Flush Cache Extended). So the drive doesn't actually return an error to a write command, it fails to flush the write cache to disk. This also explains why turning off the writecache avoids the issue.

Bye, Martin