>>>>> "Bernd" == Bernd Schubert <bernd.schubert@xxxxxxxxxxx> writes: Hey Bernd, Bernd> I'm afraid we have another problem. I'm currently working on to Bernd> get discard working for our LSI2008 HBAs with attached sata-SSDs Bernd> and the heuristics in sd_read_write_same with based on VPD page Bernd> 0x89 is not correct for this HBA - its SATL supports write-same This has nothing to do with the WRITE SAME heuristics. It's true that depending on wind and whether we might issue WRITE SAME(10) or (16) with the UNMAP bit set to perform discard operations on the low level device. But we use a set of different (and somewhat more reliable) heuristics to decide which command to send down for that purpose. For discards to a SATA device to work you need a recent phase LSI firmware. And you need the target mode firmware (IT). There is no UNMAP->DSM TRIM translation in the RAID (IR) firmware. If your SATA SSDs reports DSM TRIM support, the LSI firmware will set LBPME=1 in READ CAPACITY(16) and the LOGICAL BLOCK PROVISIONING VPD page will indicate a preference for the UNMAP command (LBPU=1). Also, LSI firmware is well-behaved in general and will report ILLEGAL REQUEST when you send down a command that can't be handled. -- Martin K. Petersen Oracle Linux Engineering -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
