I was under the same impression - using a small portion of the SSD via partitioning (in my case - 30 gigs out of 240) would have the same effect as activating the HPA explicitly.
Am I wrong? On Nov 7, 2013, at 8:16 PM, ja...@peacon.co.uk wrote: > On 2013-11-07 17:47, Gruher, Joseph R wrote: > >> I wonder how effective trim would be on a Ceph journal area. >> If the journal empties and is then trimmed the next write cycle should >> be faster, but if the journal is active all the time the benefits >> would be lost almost immediately, as those cells are going to receive >> data again almost immediately and go back to an "untrimmed" state >> until the next trim occurs. > > If it's under-provisioned (so the device knows there are unused cells), the > device would simply write to an empty cell and flag the old cell for erasing, > so there should be no change. Latency would rise when sustained write rate > exceeded the devices' ability to clear cells, so eventually the stock of > ready cells would be depleted. > > FWIW, I think there is considerable mileage in the larger-consumer grade > argument. Assuming drives will be half the price in a years time, so > selecting devices that can last only a year is preferable to spending 3x the > price on one that can survive three. That though opens the tin of worms that > is SMART reporting and moving journals at some future point mind. _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
