removing external journal

[Folkert van Heusden]

Eric, Andreas,

>>> I have a system with an ext4 filesystem with its journal on an other
>>> device (an SSD).
>>> Now this SSD dropped of the sata bus so the filesystem went r/o.
>>> I would like to remove the journal but it says it can't because
>>> needs_check is set.
>>
>> What does it actually say?  there is no needs_check flag AFAIK.
>
> I think he means "needs_recovery" - EXT3_FEATURE_INCOMPAT_RECOVER
> set when journal recovery is needed after an unclean shutdown.

Yes, that's the one.

> What you want is to run (per the tune2fs(8) man page, maybe something
> should go into the e2fsck(8) man page as well?):
>    tune2fs -f -O ^has_journal /dev/XXX

That one was denied because of the needs_recovery.

Fortunately I was able to bring the SSD back to life and got it all to recover!

The problem was with an intel motherboard with a couple of sata ports.
4 of them are from a marvell chipset and those give lots of problems.
I moved all hdds and ssds to the other ports and hopefully that solves
the instability.

> What is interesting is that the filesystem _should_ be able to
> handle the loss of the journal device by first dropping the
> RECOVER feature and instead marking itself dirty as it would for
> ext2.  It needs a full e2fsck after an unclean shutdown in either
> case, though a clean shutdown would be totally safe, and no further
> action would be needed if the journal device returned at some later
> time.  The journal device shouldn't make the filesystem _less_
> reliable.

Oh funny thing: after powering up the system again, the system said
that the filesystem said it was clean while there were changes pending
in the journal! After applying those changes, one filesystem was
hosed, the other was fine. Hooray for backups.


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