Re: [zfs-discuss] HW raid vs ZFS

2010-01-11 Thread Bob Friesenhahn
On Mon, 11 Jan 2010, Anil wrote: ZFS will definitely benefit from battery backed RAM on the controller as long as the controller immediately acknowledges cache flushes (rather than waiting for battery-protected data to flush to the I am little confused with this. Do we not want the controlle

Re: [zfs-discuss] HW raid vs ZFS

2010-01-11 Thread Toby Thain
On 11-Jan-10, at 1:12 PM, Bob Friesenhahn wrote: On Mon, 11 Jan 2010, Anil wrote: What is the recommended way to make use of a Hardware RAID controller/HBA along with ZFS? ... Many people will recommend against using RAID5 in "hardware" since then zfs is not as capable of repairing err

Re: [zfs-discuss] HW raid vs ZFS

2010-01-11 Thread Anil
> ZFS will definitely benefit from battery backed RAM > on the controller > as long as the controller immediately acknowledges > cache flushes > (rather than waiting for battery-protected data to > flush to the I am little confused with this. Do we not want the controller to ignore these cache

Re: [zfs-discuss] HW raid vs ZFS

2010-01-11 Thread Bob Friesenhahn
On Mon, 11 Jan 2010, Anil wrote: What is the recommended way to make use of a Hardware RAID controller/HBA along with ZFS? Does it make sense to do RAID5 on the HW and then RAIDZ on the software? OR just stick to ZFS RAIDZ and connect the drives to the controller, w/o any HW RAID (to benefi

[zfs-discuss] HW raid vs ZFS

2010-01-11 Thread Anil
I am sure this is not the first discussion related to this... apologies for the duplication. What is the recommended way to make use of a Hardware RAID controller/HBA along with ZFS? Does it make sense to do RAID5 on the HW and then RAIDZ on the software? OR just stick to ZFS RAIDZ and connect