Re: Snapshots slowing system

[Duncan <1i5t5.duncan@cox.net>]

Austin S. Hemmelgarn posted on Fri, 18 Mar 2016 07:38:29 -0400 as
excerpted:

>>> 188 Command_Timeout         0x0032   100   099   000    Old_age  
>>> Always
>>>        -       8590065669
>>
>> Again, a non-zero raw value indicating command timeouts, probably due
>> to those bad seeks.  It'll have to retry those commands, and that'll
>> definitely mean slowdowns.
>>
>> Tho there's no threshold, but 99 worst-value cooked isn't horrible.
>>
>> FWIW, on my spinning rust device this value actually shows a worst of
>> 001, here (100 current cooked value, tho), with a threshold of zero,
>> however.  But as I've experienced no problems with it I'd guess that's
>> an aberration.  I haven't the foggiest why/how/when it got that 001
>> worst.

> Such an occurrence is actually not unusual when you have particularly
> bad sectors on a 'desktop' rated HDD, as they will keep retrying for an
> insanely long time to read the bad sector before giving up.

Which is why it's mystifying to me how it could be reporting a worst-
value 1, when the device seems to be working just fine, and I don't 
recall even one event of waiting "an insanely long time", or even 
anything out of the ordinary, for anything on that device, ever.

Tho I suppose it's within reason that whatever it was froze up the system 
bad enough that I rebooted, and I attributed the one-off to something 
else.  But with no other attributes indicating issues, I remain clueless 
as to what might have happened and why that 1-worst, particularly so 
given the 0 threshold for that attribute and that it's an old-age 
indicator rather than a fail indicator, but the device is neither that 
old, nor as I said, in any other way indicating anything close to what 
that 1-worst value for just that single attribute implies.

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman