Re: 8K recordsize bad on ZFS?

On 05/10/10 20:39, Josh Berkus wrote:
> On 5/9/10 1:45 AM, Dimitri wrote:
>> Josh,
>>
>> it'll be great if you explain how did you change the records size to
>> 128K? - as this size is assigned on the file creation and cannot be
>> changed later - I suppose that you made a backup of your data and then
>> process a full restore.. is it so?
>
> You can change the recordsize of the zpool dynamically, then simply copy
> the data directory (with PostgreSQL shut down) to a new directory on
> that zpool.  This assumes that you have enough space on the zpool, of
> course.

Other things could have influenced your result - 260 MB/s vs 300 MB/s is
close enough to be influenced by data position on (some of) the drives.
(I'm not saying anything about the original question.)