On Sat, Oct 27, 2012 at 12:35 PM, Jim Klimov wrote:
> 2012-10-27 20:54, Toby Thain wrote:
>
>> Parity is very simple to calculate and doesn't use a lot of CPU - just
>>> slightly more work than reading all the blocks: read all the stripe
>>> blocks on all the drives involved in a stripe, then do
On Sat, Oct 27, 2012 at 9:21 AM, Edward Ned Harvey
(opensolarisisdeadlongliveopensolaris) <
opensolarisisdeadlongliveopensola...@nedharvey.com> wrote:
> > From: Edward Ned Harvey (opensolarisisdeadlongliveopensolaris)
> >
> > Performance is much better if you use mirrors instead of raid.
> (Seque
2012-10-27 20:54, Toby Thain wrote:
Parity is very simple to calculate and doesn't use a lot of CPU - just
slightly more work than reading all the blocks: read all the stripe
blocks on all the drives involved in a stripe, then do a simple XOR
operation across all the data. The actual checksums a
On 27/10/12 11:56 AM, Ray Arachelian wrote:
On 10/26/2012 04:29 AM, Karl Wagner wrote:
Does it not store a separate checksum for a parity block? If so, it
should not even need to recalculate the parity: assuming checksums
match for all data and parity blocks, the data is good.
...
Parity is
On 10/26/2012 04:29 AM, Karl Wagner wrote:
>
> Does it not store a separate checksum for a parity block? If so, it
> should not even need to recalculate the parity: assuming checksums
> match for all data and parity blocks, the data is good.
>
> I could understand why it would not store a checksum
> From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss-
> boun...@opensolaris.org] On Behalf Of Fajar A. Nugraha
>
> So my
> suggestion is actually just present one huge 25TB LUN to zfs and let
> the SAN handle redundancy.
Oh - No
Definitely let zfs handle the redundancy. Because Z
> From: Edward Ned Harvey (opensolarisisdeadlongliveopensolaris)
>
> Performance is much better if you use mirrors instead of raid. (Sequential
> performance is just as good either way, but sequential IO is unusual for most
> use cases. Random IO is much better with mirrors, and that includes scr