Re: libata pm

[Mark Lord <liml@rtr.ca>]

dusty@gmx.li wrote:
>>> Sorry for my late answer, but i had to sort this out first.
>>> After replacing the first PSU with a new Corsair 650W the power no
>>> longer fluctuated more than 0,01 V (and this only when booting up the
>>> drives...) I did a full resync on both raid arrays and got no more
>>> errors or resets, but there were some inconsitencies during sync and the
>>> xfs filesystem on both arrays had to be repaired. Are these problems
>>> caused by the pm resets ?
>>>
>> libata EH won't lose any data as long as the hardware doesn't.  If power
>> fluctuates causing your drive to briefly power down - this does happen and
>> you can hear the drive doing emergency unload when it happens, the data in
>> write buffer can be lost.  On coming back, all that libata can know is
>> that the PHY suffered brief connection loss, so it resets the device and
>> goes on, so the data in the cache is lost now.  It's basically pulling the
>> power plug from the harddrive while write is going on and connecting it
>> back quickly.  You're bound to lose data.
>>
> After I got the new PSU and the raid was in full sync without any error
> for 48h, I thought all problems were gone. Today the sata errors
> reappeared and whenever the load is high enough I get the following:
..

What exact brand/model drives are those again (hdparm --Istdout, please) ?

If I have a similar unit here, I may try to reproduce this.

Cheers