On 4/16/2010 10:30 AM, Bob Friesenhahn wrote: > On Thu, 15 Apr 2010, Eric D. Mudama wrote: >> >> The purpose of TRIM is to tell the drive that some # of sectors are no >> longer important so that it doesn't have to work as hard in its >> internal garbage collection. > > The sector size does not typically match the FLASH page size so the > SSD still has to do some heavy lifting. It has to keep track of many > small "holes" in the FLASH pages. This seems pretty complicated since > all of this information needs to be well-preserved in non-volatile > storage. > But doesn't the TRIM command help here. If as the OS goes along it makes sectors as unused, then the SSD will have a lighter wight lift to only need to read for example 1 out of 8 (assuming sectors of 512 bytes, and 4K FLASH Pages) before writing a new page with that 1 sector and 7 new ones.
Additionally in the background I would think it would be able to find a Page with 3 inuse sectors and another with 5 for example, write all 8 to a new page, remap those sectors to the new location, and then pre-erase the 2 pages just freed up. How doesn't that help? -Kyle > Bob > -- > Bob Friesenhahn > bfrie...@simple.dallas.tx.us, > http://www.simplesystems.org/users/bfriesen/ > GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
