Re: Disk performance deteriated to unbearable levels
Miles Fidelman writes:
> Stan Hoeppner wrote:
>> On 11/9/2011 1:34 AM, Bob Proulx wrote:
>>> Miles Fidelman wrote:
>>>> try smartctl -A /dev/sda
>>>> that will give you a much longer list of statistics collected by
>>>> the drive
>>>> the one I always look at first is the absolute value of "raw read
>>>> errors" - if that's higher than 0, the drive is starting to fail,
>>>> and its internal code is spending more and more time trying to read
>>>> and re-read data off the media
>>> Excellent information!
>> Not really. The numbers are not absolutes. And they differ among
>> manufacturers. S.M.A.R.T. is a data format standard for "drive
>> health", but it does not dictate "value" standards for the field
>> For the end user, attempting to interpret some S.M.A.R.T. data for
>> some makes of drives is hit or miss. I would say as a general rule
>> that one should contact the drive manufacturer if s/he sees
>> S.M.A.R.T. error counts rise. The drive may or may not be failing.
> Specifically for "raw read error" - in the format
> ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED
> 1 Raw_Read_Error_Rate 0x000b 088 088 062 Pre-fail Always - 3342368
> I've found, across many different dries, that the "VALUE" field (which
> is a relative field calculated over time) is generally useless, while
> the RAW_VALUE field is almost always indicative of pending failure if
> it's value is anything other than 0.
All my drives have a RAW_VALUE for that parameter not equal to 0:
machine1$ sudo smartctl -A /dev/sdb | grep "Read\|Power_On"
1 Raw_Read_Error_Rate 0x000f 108 099 006 Pre-fail Always - 18696503
9 Power_On_Hours 0x0032 087 087 000 Old_age Always - 11987
machine1$ sudo smartctl -A /dev/sda | grep "Read\|Power_On"
1 Raw_Read_Error_Rate 0x000f 111 086 006 Pre-fail Always - 35575453
9 Power_On_Hours 0x0032 069 069 000 Old_age Always - 27906
Even with new drives:
machine2$ sudo smartctl -A /dev/sdb | grep -e "Read\|Power_On"
1 Raw_Read_Error_Rate 0x000f 117 100 006 Pre-fail Always - 131149163
9 Power_On_Hours 0x0032 100 100 000 Old_age Always - 475
machine2$ sudo smartctl -A /dev/sdc | grep -e "Read\|Power_On"
1 Raw_Read_Error_Rate 0x000f 111 100 006 Pre-fail Always - 31090694
9 Power_On_Hours 0x0032 100 100 000 Old_age Always - 285
Those are all Seagate drives. Maybe their raw value means something