[smartmontools-support] Inconsistent long test times

[Kent Watsen]

The saga continues  ;)

> Vedant  wrote:
> 
> Sorry, both seem to be SMR drives. My bad.

Indeed...a somewhat unpleasant surprise.

I have one more day to return them but, in an attempt to salvage them, I’m thinking to relegate them for “cold” storage use.  That said, I’ve learned that it may be advantageous to “ATA secure erase" them (wipe out all SMR info) whenever repurposing them (or else the resilvering process slows to a crawl).

According this forum page [1]:

    "For SMR to be useful to the world it NEEDS it's own version of
     TRIM support. It's god awful once you start re-writing or using
     empty space that previously contained data.”

And:

    "Many of the WD SMR disks do actually support TRIM. I’ve 
      always wished my Seagates would.”

Here’s " the "TRIM Command” line from the "--all” output for each device type:

    Seagate Barracuda:	TRIM Command:     Available
    WD WD20SPZX:	 	TRIM Command:     Available, deterministic
    Intel DC 3700 SSD*:	TRIM Command:     Available, deterministic, zeroed

    * adding this SSD to the list only because its output differs.

I’m new to all this, but does “Available" mean that all of these drives do in fact support that which the posters are wishing for?  I assume that “deterministic” refers to DRAT and "deterministic, zeroed” refers to DZAT.  Given the differences, could it be that, in order for a SMR-based disk to the wiped, it must be "Available, deterministic” (not just “Available”)?

Does this make any sense to anyone?

[1]  https://www.reddit.com/r/zfs/comments/g1v609/zfs_with_shingled_magnetic_drives_smr_detailed


Thanks,
Kent