Re:WD Passport 4TB drives don't support WRITE SAME command
by jjoonathan on Thursday March 26, 2020 @05:54PM
(#22698378)
Oh, so WRITE SAME doesn't come with "no wear leveling" semantics? That makes emulation much more reasonable.
Re:WD Passport 4TB drives don't support WRITE SAME command
by kllrnohj on Thursday March 26, 2020 @08:01PM
(#22699253)
I think the only way to get "no wear leveling" is the ATA Secure Erase command. Which you only need for devices that do wear leveling in the first place which the drive in question doesn't anyway so it's a bit moot.
Re:WD Passport 4TB drives don't support WRITE SAME command
by pixl97 on Thursday March 26, 2020 @05:04PM
(#22697981)
Would that work on a filesystem that supports sparse files?
Re:WD Passport 4TB drives don't support WRITE SAME command
by throwaway373438 on Thursday March 26, 2020 @05:10PM
(#22698028)
We're talking about the filesystem driver itself issuing the write.
The above is a discussion about whether the filesystem driver or the block device driver would issue the SCSI commands.
This would never happen from userspace.
Re:WD Passport 4TB drives don't support WRITE SAME command
by tedunangst on Thursday March 26, 2020 @06:27PM
(#22698621)
Why would you need to overwrite blocks of a sparse file? Which blocks would you be overwriting?
Issue normal data writes of blocks that are filled with zeros. The same way regular data makes it to the drive just fine will also of course work for data that's all zeros.