>>>>> "Bernd" == Bernd Schubert <bernd.schubert@xxxxxxxxxxx> writes: Bernd, Bernd> Both types of systems we have in-house neither block limits vpd Bernd> nor READ_CAP16 return anything that would indicate discard is Bernd> supported. But UNMAP and WRITE SAME unmap(*) just work fine. I have a collection of different SSDs in a tray connected to an LSI SAS2008 ASIC. The 510 is the only drive that does not have LBPME=1. Chances are it's because DRAT and RZAT are not set but it could also be that the 510 is blacklisted. Bernd> I certainly don't want to cause any more write-same trouble, but Bernd> as all layers initially have to assume write same is supported Bernd> anyway and need to dynamically disable it if it fails, can't we Bernd> also enable discard by default with WRITE SAME16 unmap? No thanks :) But you can force discards on by doing a: # echo -n unmap > /sys/class/scsi_disk/x:y:z:n/provisioning_mode or # echo -n writesame_16 > /sys/class/scsi_disk/x:y:z:n/provisioning_mode Create a udev rule if you like. In any case I wouldn't recommend using TRIM on that drive... Bernd> PS: LSI SATL with FWv17 seems to have an unmap bug - I cannot Bernd> unmap the last sector: Yes, it appears there's an off-by-one bug in the UNMAP translation. Sumit, is this something you guys can look into? -- Martin K. Petersen Oracle Linux Engineering -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
