On Wed, Feb 9 at 10:00, Scott E. Armitage wrote:
I reiterate my previous reply that under the current md architecture, where the complete device is considered to be in use, sending TRIM commands makes little sense. AFAICT, reading back a trimmed page is not defined, since the whole idea is that the host doesn't care about what is on that page any more. The next time md comes around to corresponding trimmed pages on two SSDs, their contents may differ, and all of a sudden our array is no longer consistent.
For SATA devices, ATA8-ACS2 addresses this through Deterministic Read After Trim in the DATA SET MANAGEMENT command. Devices can be indeterminate, determinate with a non-zero pattern (often all-ones) or determinate all-zero for sectors read after being trimmed. --eric -- Eric D. Mudama edmudama@xxxxxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
