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Date: Wed, 21 Oct 2015 08:30:42 -0600 (MDT)
From: Warren Block <wblock@wonkity.com>
To: "Brandon J. Wandersee" <brandon.wandersee@gmail.com>
cc: krad <kraduk@gmail.com>, FreeBSD Questions <freebsd-questions@freebsd.org>
Subject: Re: gjournal and TRIM: A safe combination?
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On Wed, 21 Oct 2015, Brandon J. Wandersee wrote:

>
> krad writes:
>
>> I thought SU+J was the preferred method these days, not gjournal. I quite
>> out of touch with ufs these days though.
>>
>
> I thought the opposite, myself. `gjournal` has its own section in the
> Handbook, while SU+J isn't even mentioned. I also thought there was
> something fundamentally different about them--like SU+J simply maintains
> filesystem integrity, while gjournal actually protects files from the
> write hole as well as protecting the filesystem. I could be wrong.

This is correct.  SUJ is only concerned with filesystem integrity.

But if you are considering gjournal, why not go the whole way and just 
use ZFS?