[OmniOS-discuss] No I/O on ZIL logs?
steve at linuxsuite.org
steve at linuxsuite.org
Mon Jan 7 12:21:55 EST 2013
> On Mon, Jan 7, 2013 at 12:08 PM, <steve at linuxsuite.org> wrote:
>> zfs set sync=always data1
>>
>> default is sync=standard
>
> Note that this will cause a substantial performance penalty, even when
> a slog device is present. You're effectively turning *all* I/O to the
> data1 pool into synchronous I/O, even if the application didn't ask
> for it.
Yes I am aware of this.
We have a special requirement that demands data integrity
and are willing to trade performance for it.
thanx - steve
Here are some numbers
capacity operations bandwidth
pool alloc free read write read write
--------------------------- ----- ----- ----- ----- ----- -----
data1 10.2T 16.6T 0 4.74K 0 79.8M
raidz2 10.2T 16.6T 0 1.60K 0 35.7M
c5t5000C500525BFB31d0s0 - - 0 55 0 5.74M
c5t5000C500525C2F91d0s0 - - 0 55 0 5.73M
c5t5000C500525C72B1d0s0 - - 0 55 0 5.73M
c5t5000C500525C9673d0s0 - - 0 55 0 5.73M
c5t5000C500489956C1d0s0 - - 0 55 0 5.73M
c5t5000C500525EB2B9d0s0 - - 0 54 0 5.73M
c5t5000C500525F2297d0s0 - - 0 54 0 5.73M
c5t5000C50045561CEAd0s0 - - 0 55 0 5.73M
c5t5000C50048990BE6d0s0 - - 0 55 0 5.73M
c5t5000C500489947A8d0s0 - - 0 54 0 5.74M
logs - - - - - -
mirror 1.53G 146G 0 3.14K 0 44.1M
c1t2d0 - - 0 3.14K 0 44.1M
c1t4d0 - - 0 3.14K 0 44.1M
cache - - - - - -
c1t5d0 111G 48.5K 0 297 0 30.7M
--------------------------- ----- ----- ----- ----- ----- -----
capacity operations bandwidth
pool alloc free read write read write
--------------------------- ----- ----- ----- ----- ----- -----
data1 10.2T 16.6T 0 5.77K 0 83.0M
raidz2 10.2T 16.6T 0 2.04K 0 39.4M
c5t5000C500525BFB31d0s0 - - 0 70 0 6.60M
c5t5000C500525C2F91d0s0 - - 0 70 0 6.60M
c5t5000C500525C72B1d0s0 - - 0 70 0 6.60M
c5t5000C500525C9673d0s0 - - 0 69 0 6.60M
c5t5000C500489956C1d0s0 - - 0 69 0 6.60M
c5t5000C500525EB2B9d0s0 - - 0 70 0 6.59M
c5t5000C500525F2297d0s0 - - 0 70 0 6.60M
c5t5000C50045561CEAd0s0 - - 0 70 0 6.59M
c5t5000C50048990BE6d0s0 - - 0 69 0 6.59M
c5t5000C500489947A8d0s0 - - 0 69 0 6.59M
logs - - - - - -
mirror 2.40G 146G 0 3.72K 0 43.6M
c1t2d0 - - 0 3.72K 0 43.6M
c1t4d0 - - 0 3.72K 0 43.6M
cache - - - - - -
c1t5d0 111G 99K 0 264 4.13K 26.0M
--------------------------- ----- ----- ----- ----- ----- -----
capacity operations bandwidth
pool alloc free read write read write
--------------------------- ----- ----- ----- ----- ----- -----
data1 10.2T 16.6T 0 4.48K 1.58K 90.1M
raidz2 10.2T 16.6T 0 1.80K 1.58K 38.5M
c5t5000C500525BFB31d0s0 - - 0 63 0 6.28M
c5t5000C500525C2F91d0s0 - - 0 62 808 6.28M
c5t5000C500525C72B1d0s0 - - 0 62 0 6.29M
c5t5000C500525C9673d0s0 - - 0 62 808 6.29M
c5t5000C500489956C1d0s0 - - 0 62 0 6.28M
c5t5000C500525EB2B9d0s0 - - 0 62 0 6.28M
c5t5000C500525F2297d0s0 - - 0 61 0 6.29M
c5t5000C50045561CEAd0s0 - - 0 62 0 6.29M
c5t5000C50048990BE6d0s0 - - 0 62 0 6.29M
c5t5000C500489947A8d0s0 - - 0 63 0 6.29M
logs - - - - - -
mirror 2.61G 145G 0 2.68K 0 51.6M
c1t2d0 - - 0 2.68K 0 51.6M
c1t4d0 - - 0 2.68K 0 51.6M
cache - - - - - -
c1t5d0 111G 80K 0 292 303 31.6M
--------------------------- ----- ----- ----- ----- ----- -----
>
> A better solution to test ZIL would be to leave the sync property as
> default but run a test that does synchronous I/O.
>
> Eric
>
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