Re: frequent disk error, need guidance

On Sat, 15 Apr 2023 18:50:41 -0700, Gary Aitken wrote:
> On 4/15/23 13:47, John Levine wrote:
> > It appears that Gary Aitken <freebsd@dreamchaser.org> said:
> >> of fbsd in such cases), wanted to see if the following is a good way
> >> to copy the old disk to the new one.
> >>
> >> mount /dev/ada1p2 /mnt/newsys
> >> cd /mnt/newsys
> >> dump -0 -f - /dev/ada0p2 | restore -r -Dv -f -
> >>
> >> However... this is a running system, which seems unlikely to produce
> >> a consistent result.
> > 
> > I'd shut down to single user, make a /.snap directory, and do dump -L
> > to tell it to make a snapshot before dumping.  That should work OK.
> 
> Thanks.
> (Needed to mount /tmp read-write)
> The -L didn't work because boot -s mounted the filesystem read-only;
> at least that's what it claimed:
> 
> dump -0 -L -f - /dev/ada0p2 | restore -r -Dv -f -
> Verify tape and initialize maps
>    DUMP: WARNING: -L ignored for read-only filesystem

That is correct: -L is used to make a "runtime snapshot"
of a filesystem that could be subject to changes, i. e.
to writes.



> Not sure I understand that;
> does -s normally start in read-only mode?

Yes. Single-user mode starts the system with the root
partition / mounted read-only, and all other partitions
not mounted at all. If you have "one big /", this will
also apply. If you have separate /tmp, /var, /usr, /opt,
/home etc. partitions, you need to fsck and then mount
them manually, after "mount -wu /".



> Has it always done that?  It's been quite a while since I did that.

Yes, as far as I remember, and I remember since 4.0. ;-)



> In any case, I let the dump|restore go through, and it seems to have
> been successful.  Booted into the restored system and running it now;
> smartctl short test ok and doing long now.

Excellent!



> It looks like the bad blocks/sectors were files in
>    /var/db/freebsd-update/files/xxx.gz
> I unzipped a file in that directory and it appears that they are the
> saved files from the old system when upgrading.  Is that correct?
> Any reason not to remove all files in
>    /var/db/freebsd-update/files
> since the upgraded to 12.x system has been running for several months
> now?

Those seem to be temporary files belonging to the
updating program. There's probably nothing wrong
with deleting them, as if they are needed, then
freebsd-update would fetch or generate them anyway.





-- 
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...