> On 18 Jun 2018, at 08:27, Oliver Weinmann <[email protected]> wrote: > > Hi, > > we have a HGST4u60 SATA JBOD with 24 x 10TB disks. I just saw that back then > when we created the pool we only cared about disk space and so we created a > raidz2 pool with all 24disks in one vdev. I have the impression that this is > cool for disk space but is really bad for IO since this only provides the IO > of a single disk. We only use it for backups and cold CIFS data but I have > the impression that especially running a single VEEAM backup copy job really > maxes out the IO. In our case the VEEAM backup copy job reads and writes the > data from the storage. Now I wonder if it makes sense to restructure the > Pool. I have to admit that I don't have any other system with a lot of disk > space so I can't simply mirror the snapshots to another system and recreate > the pool from scratch. > > Would adding two ZIL SSDs improve performance? > > Any help is much appreciated. > > Best Regards, > Oliver
Hi, I would be interested to know as well. Sometimes we have same issue: need for large space vs need to optmise for speed (read, write, or both). We also are using, at the moment, 10TB disks, although never do RAID-Z2 with more than 10 disks. This page has some testing that was useful to us: https://calomel.org/zfs_raid_speed_capacity.html Section «Spinning platter hard drive raids» has your use case (although 4TB, not 10TB): 24x 4TB, 12 striped mirrors, 45.2 TB, w=696MB/s , rw=144MB/s , r=898MB/s 24x 4TB, raidz (raid5), 86.4 TB, w=567MB/s , rw=198MB/s , r=1304MB/s 24x 4TB, raidz2 (raid6), 82.0 TB, w=434MB/s , rw=189MB/s , r=1063MB/s 24x 4TB, raidz3 (raid7), 78.1 TB, w=405MB/s , rw=180MB/s , r=1117MB/s 24x 4TB, striped raid0, 90.4 TB, w=692MB/s , rw=260MB/s , r=1377MB/s Different adapters/disks will change the results, but I do not thing ratio will change much. It would be interesting to see how ZIL would affect that. Priyadarshan _______________________________________________ OmniOS-discuss mailing list [email protected] http://lists.omniti.com/mailman/listinfo/omnios-discuss
