[ADMIN] ZFS-FreeBSD + postgresql performance

[Steven Hartland]

----- Original Message ----- 
From: <Ivailo.TANUSHEFF at raiffeisen.bg>
>> ----- Original Message ----- 
>> From: "Patrick Dung" <patrick_dkt at yahoo.com.hk>
>> Sent: Friday, October 25, 2013 4:53 PM
>> Subject: Re: [ADMIN] ZFS-FreeBSD + postgresql performance
>> 
>> 
>> >> I would also recommend to use 4K sector size using
>> >
>> > gnop and zpool export/import.
>> 
>> This will have no effect, the ashift for a pool is set at creation.
>> 
>>     Regards
>>     Steve
>> 
> 
> That's the idea: to set the ashift during the creation of the pool. Never 
> did that before?
> 
> gnop create -S 4096 /dev/gpt/disk0
> gnop create -S 4096 /dev/gpt/disk1
> zpool create mirror /dev/gpt/disk0.nop /dev/gpt/disk1.nop
> zpool export zroot
> gnop destroy /dev/gpt/disk0.nop
> gnop destroy /dev/gpt/disk1.nop
> zpool import zroot

First if your on 10 or 11 you don't need this unless you have a disk
which is 4k but is reporting 512b and isnt in our list of quirks.

If you still need to do this you only need to do gnop create / destroy
onone disk per top level vdev so in your example thats only one disk.

    Regards
    Steve

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