>>>>> "Tom" == Tom Yan <tom.ty89@xxxxxxxxx> writes: Tom> Today I check if blkdiscard really does a full device trim/wipe for Tom> my Intel 530 SSD (240gb) with hexdump. I end up found that it fail Tom> to do so because it report garbage info on its block limits VPD. It is a SATA-attached drive, it has no block limits VPD. What you are seeing is information prepared by libata's SATL. Tom> The fact is, in each iteration, for this drive, blkdiscard can only Tom> trim a maximum of 65528 sectors, which is the largest multiple of 8 Tom> sectors, which is the minimum possible. Maximum write same length: 0x3fffc0 blocks That's 2GB-e per request for a drive with 512-byte logical blocks. Tom> but still I would like to know why the kernel doesn't allow Tom> "discard_granularity" and "discard_max_bytes" to be configurable Tom> for users. Because if the vendor got these trivial values wrong there is little to no chance that they implemented discard correctly in their firmware. -- Martin K. Petersen Oracle Linux Engineering -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
