UFS gjournal vs soft updates journaling

At the moment I use SU.

Today a server crash and rebooted. Then it crash again few times (after running the fsck automatically at boot). I have seen the same issue in the past and I was able to solve it by booting in rescue mode (mfsbsd) and manually run fsck. Fsck took a long time as the gmirror was rebuilding.

I try to find if SU+J will solve this issue.
This crash might be related to disks' condition more then to UFS.
SU+j (soft updates journaling, to distinguish from the -J flag in tunefs, which is geom_journal) works pretty good.
 
Hi!

To clarify my confusion. I see and have seen Soft Updates mentioned with "+j" journaling. But I have understood both these as an alternative to "-J" geom_journal alone. So I am wondering if it is at all possible and useful to use geom_journal with Soft Updates?

Thanks.
 
2016:

I'm still convinced that SUJ only journals filesystem metadata. See #3 here: http://www.ivoras.net/blog/tree/2013-10-24.why-ufs-in-freebsd-is-great.html.

However, my experience with SUJ was poor, and I only use SU.

Now in the Wayback Machine:

<https://web.archive.org/web/2020021...e/2013-10-24.why-ufs-in-freebsd-is-great.html>

… SU+J does not support UFS snapshots, …

… UFS (Regular) and UFS (SU) make sense on SSDs and small file systems. …

Use SU+J for new filesystems,

As neither feature is a default with newfs(8):
  • why do people sometimes choose to enable soft updates without soft update journaling?
Is the reason still incompatibility with snapshots?


Journaled Soft-updates

That 2012 PDF is useful, I wish I had known of it long ago. (Random discovery. IRC ▶ #freebsd-bugs ▶ <https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=259293> ▶ <https://www.freshports.org/sysutils/freebsd-snapshot/> ▶ <https://people.freebsd.org/~rse/snapshot/> ▶ References ▶ <https://www.mckusick.com/softdep/> ▶ final sentence: For information about journaled soft updates click here.)

There's no explanation of soft update journaling in the Handbook (it's not even mentioned in the section about soft updates). I'll make a bug report for something to be added, with reference to the PDF.
 
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