20,000 reallocations and drive is still serviceable?

[fzabkar]

It used to be that WD's drives would hit a SMART threshold when the number of reallocated sectors reached 500.

Here is a WD40NDZW that has racked up 50,392 reallocations (= 6299 physical sectors):

The normalised value has dropped from 200 to 182, so this suggests that the drive is spec'ed for 20,000 reallocated physical sectors.

50392 / 8 / (200 - 182) x (200 -140) = 20997
50392 / 8 / (200 - 181) x (200 -140) = 19892

Seagate has been doing this for many years, but I hadn't noticed that WD's drives had also gone down this path.

[Arch Stanton]

has racked up 50,392 reallocations (= 6299 physical sectors)

Is that how this works with 4k sectors? I didn't know this.

[fzabkar]

has racked up 50,392 reallocations (= 6299 physical sectors)

Is that how this works with 4k sectors? I didn't know this.

I assumed so, but now I see that the pending sector count is 10 which is not a multiple of 8. :-?

The drive in the following thread does seem to fit my assumption, though:

https://forum.hddguru.com/viewtopic.php?f=1&t=41771

This WD40NDZW SMART report suggests that attributes #5 and #196 count logical sectors whereas #197 counts physical sectors:

https://bbs.archlinux.org/viewtopic.php?id=260538

Code:

Device Model:     WDC WD40NDZW-11MR8S1

  5 Reallocated_Sector_Ct   0x0033   198   198   140    Pre-fail  Always       -       304
196 Reallocated_Event_Count 0x0032   001   001   000    Old_age   Always       -       304
197 Current_Pending_Sector  0x0032   199   199   000    Old_age   Always       -       883

[Arch Stanton]

has racked up 50,392 reallocations (= 6299 physical sectors)

Is that how this works with 4k sectors? I didn't know this.

I assumed so, but now I see that the pending sector count is 10 which is not a multiple of 8.

The drive in the following thread does seem to fit my assumption, though:

https://forum.hddguru.com/viewtopic.php?f=1&t=41771

This WD40NDZW SMART report suggests that attributes #5 and #196 count logical sectors whereas #197 counts physical sectors:

https://bbs.archlinux.org/viewtopic.php?id=260538

Code:

Device Model:     WDC WD40NDZW-11MR8S1

  5 Reallocated_Sector_Ct   0x0033   198   198   140    Pre-fail  Always       -       304
196 Reallocated_Event_Count 0x0032   001   001   000    Old_age   Always       -       304
197 Current_Pending_Sector  0x0032   199   199   000    Old_age   Always       -       883

I have always wondered about 'event count' too. What does it actually count. Can it do multiple sectors in one 'event' and would it count it as one event? reason I wondered was seeing different numbers for reallocated and reallocation events.

TBH I have never actually seen the format in which sector reallocation are kept. I'm sure you know Frank, can it reallocate a range and then log it as one event?

[fzabkar]

TBH I have never actually seen the format in which sector reallocation are kept. I'm sure you know Frank, can it reallocate a range and then log it as one event?

I don't know, either.