On Thu, Mar 15, 2018 at 08:45:05AM -0400, 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. I see. So I ran `hdparm` on my SSD (still attached via the 'Thunderbolt' port), and it does show TRIM support: $> hdparm -I /dev/sdc | grep TRIM * Data Set Management TRIM supported (limit 8 blocks) (Full output attached to this e-mail as a text file.) > Have you tried to issue a DSM TRIM command via ATA > passthrough? I'm afraid I don't know how to do that (my SCSI / (S)ATA knowledge is less than zero). If there's a page where I can educate myself about how to send the TRIM command via ATA passthrough I'd appreciate it. (Aside: >From my looking up, I don't see any ATA equivalent of SCSI's 'sg3_utils'; wonder if there is any.) Thanks for the response. -- /kashyap
$> hdparm -I /dev/sdc /dev/sdc: ATA device, with non-removable media Model Number: Samsung Portable SSD T5 Serial Number: S3UNNV0K102165T Firmware Revision: MVT41P1Q Transport: Serial, ATA8-AST, SATA 1.0a, SATA II Extensions, SATA Rev 2.5, SATA Rev 2.6, SATA Rev 3.0 Standards: Used: unknown (minor revision code 0x0039) Supported: 9 8 7 6 5 Likely used: 9 Configuration: Logical max current cylinders 16383 16383 heads 16 16 sectors/track 63 63 -- CHS current addressable sectors: 16514064 LBA user addressable sectors: 268435455 LBA48 user addressable sectors: 976773168 Logical Sector size: 512 bytes Physical Sector size: 512 bytes Logical Sector-0 offset: 0 bytes device size with M = 1024*1024: 476940 MBytes device size with M = 1000*1000: 500107 MBytes (500 GB) cache/buffer size = unknown Form Factor: unknown (0x0006] Nominal Media Rotation Rate: Solid State Device Capabilities: LBA, IORDY(can be disabled) Queue depth: 32 Standby timer values: spec'd by Standard, no device specific minimum R/W multiple sector transfer: Max = 1 Current = 1 DMA: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 udma5 *udma6 Cycle time: min=120ns recommended=120ns PIO: pio0 pio1 pio2 pio3 pio4 Cycle time: no flow control=120ns IORDY flow control=120ns Commands/features: Enabled Supported: * SMART feature set * Power Management feature set * Write cache * Look-ahead * WRITE_BUFFER command * READ_BUFFER command * NOP cmd * DOWNLOAD_MICROCODE SET_MAX security extension * 48-bit Address feature set * Mandatory FLUSH_CACHE * FLUSH_CACHE_EXT * SMART error logging * SMART self-test * General Purpose Logging feature set * WRITE_{DMA|MULTIPLE}_FUA_EXT * 64-bit World wide name Write-Read-Verify feature set * WRITE_UNCORRECTABLE_EXT command * {READ,WRITE}_DMA_EXT_GPL commands * Segmented DOWNLOAD_MICROCODE * Gen1 signaling speed (1.5Gb/s) * Gen2 signaling speed (3.0Gb/s) * Gen3 signaling speed (6.0Gb/s) * Native Command Queueing (NCQ) * Phy event counters * READ_LOG_DMA_EXT equivalent to READ_LOG_EXT DMA Setup Auto-Activate optimization * Device-initiated interface power management * Software settings preservation * reserved 69[4] * DOWNLOAD MICROCODE DMA command * SET MAX SETPASSWORD/UNLOCK DMA commands * WRITE BUFFER DMA command * READ BUFFER DMA command * Data Set Management TRIM supported (limit 8 blocks) Logical Unit WWN Device Identifier: 5002538d00000000 NAA : 5 IEEE OUI : 002538 Unique ID : d00000000 Checksum: correct