Re: [zfs-discuss] Asymmetric mirroring

2009-06-16 Thread Darren J Moffat
Monish Shah wrote: The other alternative is to modify ZFS to compress L2ARC, but that sounds much more complicated to me. Any insights from ZFS developers would be appreciated. Compressing the L2ARC data shouldn't be that hard, I had to do something very similar for adding

Re: [zfs-discuss] Asymmetric mirroring

2009-06-11 Thread Richard Elling
Monish Shah wrote: Hello, Thanks to everyone who replied. Dan, your suggestions (quoted below) are excellent and yes, I do want to make this work with SSDs, as well. However, I didn't tell you one thing. I want to compress the data on the drive. This would be particularly important if an

Re: [zfs-discuss] Asymmetric mirroring

2009-06-11 Thread Monish Shah
Hello, Thanks to everyone who replied. Dan, your suggestions (quoted below) are excellent and yes, I do want to make this work with SSDs, as well. However, I didn't tell you one thing. I want to compress the data on the drive. This would be particularly important if an SSD is used, as the

Re: [zfs-discuss] Asymmetric mirroring

2009-06-10 Thread Scott Meilicke
The SATA drive will be your bottleneck, and you will lose any speed advantages of the SAS drives, especially using 3 vdevs on a single SATA disk. I am with Richard, figure out what performance you need, and build accordingly. -- This message posted from opensolaris.org __

Re: [zfs-discuss] Asymmetric mirroring

2009-06-10 Thread Richard Elling
Monish Shah wrote: Hello everyone, I'm wondering if the following makes sense: To configure a system for high IOPS, I want to have a zpool of 15K RPM SAS drives. For high IOPS, I believe it is best to let ZFS stripe them, instead of doing a raidz1 across them. Therefore, I would like to mi

Re: [zfs-discuss] Asymmetric mirroring

2009-06-10 Thread Daniel Carosone
Use the SAS drives as l2arc for a pool on sata disks. If your l2arc is the full size of your pool, you won't see reads from the pool (once the cache is primed). If you're purchasing all the gear from new, consider whether SSD in this mode would be better than 15k sas. -- This message posted

[zfs-discuss] Asymmetric mirroring

2009-06-10 Thread Monish Shah
Hello everyone, I'm wondering if the following makes sense: To configure a system for high IOPS, I want to have a zpool of 15K RPM SAS drives. For high IOPS, I believe it is best to let ZFS stripe them, instead of doing a raidz1 across them. Therefore, I would like to mirror the drives for