gjournal and TRIM: A safe combination?

Julien Cigar jcigar at ulb.ac.be
Thu Oct 22 13:15:18 UTC 2015

On Wed, Oct 21, 2015 at 02:38:16PM -0500, Brandon J. Wandersee wrote:
> Julien Cigar writes:
> > Correct me if I'm wrong but, unless there is a bug in Soft Updates (SU),
> > your FS will, in theory, never be corrupted with SU only.
> If I read this right, then, would gjournal be overkill for typical
> desktop/laptop use?  UFS2 is perhaps the only filesystems I've ever
> encountered in common use that doesn't have data journaling enabled by
> default, so that's thrown me off somewhat...

It depends of your needs, but for a typicaly desktop use it seems a bit
overkill to me.

Contrary to other filesystems UFS doesn't need journaling to avoid 
_corruption_ as SU is an alternate approach to maintain metadata

One important thing to remember is that neither SU, or SU+J, or any
journaled metadata prevents data loss: corruption != data loss. This is
where gjournal (and data=journal on EXT-like FS) comes in as datas and
metadatas are written in the journal _before_, so you avoid corruption
and data loss.

I hope SU+J will be fixed one day ...

> -- 
> =================================================================
>    		      :: Brandon Wandersee ::
>                   :: brandon.wandersee at gmail.com ::
> ==================================================================
> 'A common mistake that people make when trying to design something
> completely foolproof is to underestimate the ingenuity of complete
> fools.'
>                             			- Douglas Adams
> ==================================================================
> _______________________________________________
> freebsd-questions at freebsd.org mailing list
> https://lists.freebsd.org/mailman/listinfo/freebsd-questions
> To unsubscribe, send any mail to "freebsd-questions-unsubscribe at freebsd.org"

Julien Cigar
Belgian Biodiversity Platform (http://www.biodiversity.be)
PGP fingerprint: EEF9 F697 4B68 D275 7B11  6A25 B2BB 3710 A204 23C0
No trees were killed in the creation of this message.
However, many electrons were terribly inconvenienced.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: not available
URL: <http://lists.freebsd.org/pipermail/freebsd-questions/attachments/20151022/578bec9e/attachment.bin>

More information about the freebsd-questions mailing list