On 17/10/15 17:47, Miles Fidelman wrote:
Dominique Dumont wrote:
On Saturday 17 October 2015 14:15:52 Tony van der Hoff wrote:Yes.. and be sure to go beyond the basic tests.
Can anyone please explain what it means, and whether I should beYou should check the drive with smartctl.
worried?
See http://www.smartmontools.org/
HTH
First off, make sure it's running:
smartctl -s on -A /dev/disk0 ;for each drive, and using the
appropriate /dev/..
Then after, it's accumulated some stats:
smartctl -A /dev/disk0
For a lot of drives, the first line - raw read errors, can be very
telling - anything other than 0, and your disk is failing.
Start-up-time can be telling, if it's increasing.
The thing is, that most drives, except those designed for use in RAID
arrays, mask impending disk failures, by re-reading blocks multiple
times - they often get the data eventually, but your machine keeps
getting slower and slower.
Thanks Miles, and tomás, for your helpful replies.
I apologise for the delay in replying, but I've been away from my desk a few days.
I have however been doing some extensive googling, and it would appear that the raw read error count is something of a red herring, especially when applied to Seagate drives, as these are. Both my drives have quite high (in the millions) of RREC; numbers which are precisely matched by the Hardware ECC Recovered counts, suggesting that the RREC is merely an artifact od HHDs being essentially a mechanical device, being pushed to its limits using clever technology. The SMART extended tests reveal no problems.
The Wikipedia entry https://en.wikipedia.org/wiki/S.M.A.R.T. is particularly informative in the relative importance of these error counts; the RREC can be safely ignored, as somebody else here recently suggested.
So, back to the original problem; I think tomás hit the nail on the head. I've re-plugged the SATA cables, to no great effect; I have now ordered a couple of new cables, and will see whether that helps.
Thanks again to all.