Jerry, just some thoughts regarding this important subject. TRIM is for SATA disks and UNMAP for SAS / SCSI ?
There are also some SSD SAS disks which, as it seems, work very fine with or without periodic garbage collection. For exemple the HGST HUSSL40x0BSS60x, cf. https://www.storagereview.com/hitachi_ultrastar_ssd400sb_enterprise_ssd_review Here, Hitachi has implemented a couple of technologies (huge internal overprovisioning, if my understanding is right) in order to make these disks work under any OS and in any situation. Do you have any information about this ? My understanding is also, that Oracle recommends at the moment not to activate the periodical garbage collection algorithm (based on unmap) on Solaris 11.x. And finally, it seems that ESXi 6.7 implements such an algorithm which is reported to work well. It seems even to be possible to clean older disks SATA/SAS SSD under ESXi in order to restore their original performance. Andreas From: "Jerry Jelinek" <[email protected]> To: "illumos-developer" <[email protected]>, [email protected] Date: 09/22/2019 10:50 PM Subject: [discuss] Heads up: temporarily disabled ZFS TRIM support I have just pushed a change which disables ZFS TRIM from running against disks which advertise UNMAP support. There are some issues here which I need to diagnose and address before I re-enable this. If you want to experiment with TRIM, you can set the zfs_no_trim kernel variable to 0 in your /etc/system file, although for now, I would recommend not doing that. Let me know if there are any questions, Jerry illumos / illumos-discuss / see discussions + participants + delivery options Permalink ------------------------------------------ illumos: illumos-discuss Permalink: https://illumos.topicbox.com/groups/discuss/Tcbded5fafc0f4724-M7549e44f549f5618cb4b11fb Delivery options: https://illumos.topicbox.com/groups/discuss/subscription
