Had a parity drive aging and reporting sector re-allocation, therefore, I purchased a new drive to replace it.

 

Went with a black friday 8TB, I ran a preclear on it and everything checked out OK, so yesterday I installed it into the system and began the data re-build process.

 

Re-built is going fine, but when I look at the SMART data of the drive, it is reporting pre-fail and old age.  Is this normal or should I replace the drive with another?  Since the power on hours are accurate it does not seem to be reporting old data, so before getting too far into it, I can cancel the re-build, replace the drive with a second one I purchased and see if it reports any better.

 

Below is the SMART data I am looking at.  Thanks

 

#	Attribute Name	Flag	Value	Worst	Threshold	Type	Updated	Failed	Raw Value
1	Raw read error rate	0x000b	100	100	016	Pre-fail	Always	Never	0
2	Throughput performance	0x0005	134	134	054	Pre-fail	Offline	Never	104
3	Spin up time	0x0007	100	100	024	Pre-fail	Always	Never	0
4	Start stop count	0x0012	100	100	000	Old age	Always	Never	5
5	Reallocated sector count	0x0033	100	100	005	Pre-fail	Always	Never	0
7	Seek error rate	0x000b	100	100	067	Pre-fail	Always	Never	0
8	Seek time performance	0x0005	128	128	020	Pre-fail	Offline	Never	18
9	Power on hours	0x0012	100	100	000	Old age	Always	Never	67 (2d, 19h)
10	Spin retry count	0x0013	100	100	060	Pre-fail	Always	Never	0
12	Power cycle count	0x0032	100	100	000	Old age	Always	Never	5
22	Unknown attribute	0x0023	100	100	025	Pre-fail	Always	Never	100
192	Power-off retract count	0x0032	100	100	000	Old age	Always	Never	33
193	Load cycle count	0x0012	100	100	000	Old age	Always	Never	33
194	Temperature celsius	0x0002	222	222	000	Old age	Always	Never	27 (min/max 22/42)
196	Reallocated event count	0x0032	100	100	000	Old age	Always	Never	0
197	Current pending sector	0x0022	100	100	000	Old age	Always	Never	0
198	Offline uncorrectable	0x0008	100	100	000	Old age	Offline	Never	0
199	UDMA CRC error count	0x000a	200	200	000	Old age	Always	Never	0

The text "Pre-fail" and "Old age" are just descriptions of what the different attributes are measuring.

 

Edit - notice that you also have a column "Failed". All your attributes have the value "Never".

If you had seen a "Now" there, then you would have known that the disk considers that specific attribute to be currently failing.

 

There are a few of the Raw values that you want to stay at zero permanently. You don't want Attribute 5 (Reallocated sector count), 196 (Reallocated event count), 197 (Current pending sector) or 198 (Offline uncorrectable) to tick up because then you have problems with the drive.

 

And ifh 199 (UDMA CRC error count) is ticking up, then you have issues with the SATA cable or possibly with the electronics in the controller card or the disk.

 

The disk itself gives an indication what it likes the different values based on the colum "Value". Compare this value with the other column "Threshold" - it's a failure for any attribute to have the "Value" drop down all the way to the "Threshold" value.

Edited December 30, 20178 yr by pwm

oh goodness, I totally misunderstood what they were telling me.  At least I know the parity drive I replaced did have some 1400 reallocated sectors, so it was definitely going bad.  This one, as you note looks good and healthy.  I guess it is time to carry on, thank you for debunking my fears.

Actually, I have been thinking the exact same for a while.  I couldn't figure out why all my drives were in "pre-fail" state or old, even brand new ones.

 

This is a dead topic, but I am resurrecting it to suggest maybe a slight change in wording.  Maybe the header could say "Metric of:"

 

My biggest complaint of Unraid is that in the GUI the available options are often cryptic and un-intuitive.  "Cache: Prefer" has a totally different behavior than expected.

 

Shares are "Private" or "Secure" which has little to do with 'Private' and I think its more 'Secure' than "Secure"