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From: "Steven Hartland" <killing@multiplay.co.uk>
To: "Mark Felder" <feld@freebsd.org>,
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Subject: Re: TRIM or no TRIM?
Date: Wed, 24 Jul 2013 17:08:29 +0100
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----- Original Message -----
From: "Mark Felder"
> On Wed, Jul 24, 2013, at 10:13, Steven Hartland wrote:
>>
>> gmirror may be another alternative that may correctly work with TRIM.
>>
>> For reference correctly setup MySQL performance on ZFS works well for
>> use. Of particular interest is some of our data is highly compressible
>> making ZFS compression of particular benefit for our work load.
>>
>
> There are known interactivity issues with ZFS compression, so keep that
> in mind.
Some people have said that, we've never seen it here, quite the opposite
in fact.
> Also, you will want to make sure MySQL is on its own zfs filesystem and
> you may want to set primarycache=metadata so the database chooses what
> to keep in memory, not the filesystem. I ran a decent sized Postgres
> database of my own with compression and it was OK, but I didn't hit it
> very hard.
Depends on the setup, workload and available memory tbh I would use that
as a hard and fast rule.
Regards
Steve
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