(Sorry, accidentally dropped the lists. Adding it back & re-posting my off-list response.) On Thu, Mar 15, 2018 at 04:05:53PM +0100, Kashyap Chamarthy wrote: > On Thu, Mar 15, 2018 at 03:33:46PM +0100, Douglas Gilbert wrote: > > On 2018-03-15 02:44 PM, Douglas Gilbert wrote: > > > On 2018-03-15 01:45 PM, Martin K. Petersen wrote: > > > > > > > > Kashyap, > > > > > > > > > /me naively wonders if it has anything to do with accessing it via > > > > > Linux. > > > > > > > > I'm guessing that the drive doesn't actually support SCSI UNMAP. I have > > > > a T3 that reports all the right things in the bl/lbpv VPD pages but also > > > > has lbpme set to 0. > > > > > > > > Interestingly enough, my T3 does appear to be a regular SATA drive > > > > behind a USB bridge. Have you tried to issue a DSM TRIM command via ATA > > > > passthrough? > > > > > > hdparm can do that. Look for "EXCEPTIONALLY DANGEROUS. DO NOT USE THIS > > > OPTION!!" in its manpage :-) > > Hehe, near as I see, that's dangerous only if you have data on the disk. > > This is an empty SSD that I haven't put any data in it, I should remind. > :-) In that case, I'll assume it is "safe" to tinker with the above. > > > IOWs, using Mark Lord's example: > > hdparm --trim-sector-ranges 1000:4 /dev/sdz > > > > That will attempt to trim lba 1000, 1001, 1002 and 1003 on /dev/sdz > > Thanks; I should first educate myself more on this before I tinker with > the above. One Ubuntu wiki page claims: "To wipe out contents of an SSD, > SATA secure erase is the way to go", and '--trim-sector-ranges' is only > "experimental and for benchmarking purpose". > > Just to recap: My goal is to clean (insofar as possible) the SSD of all > and any / all pre-loaded programs & re-claim space. > > --- > > Related: The ATA Secure Erase wiki page claims[*] if you do it (Secure > Erase) via USB interface, you might brick the SSD. I'm using the > 'Thunderbolt' interface, and the said wiki page doesn't say anything > useful about it. > > > [*] https://ata.wiki.kernel.org/index.php/ATA_Secure_Erase > > > -- > /kashyap -- /kashyap
