On Jul 10 17:05:55, [email protected] wrote:
> Hi Jan
> thanks for your Reply and feedback,
> please find my replies in line ,
>
> On Wed, 10 Jul 2024 at 16:28, Jan Stary <[email protected]> wrote:
> >
> > On Jul 10 14:44:28, [email protected] wrote:
> > > we have been using mfs mounted /var /dev and /tmp for years
> >
> > Why?
> so any writes to disk would be simply written a memory filesystem and
> if there was a power cut
How often do you get these power cuts?
> there would be no changes happening to the
> disk because it is being just written to memory
To be clear, you are concerned with changes to the filesystem
(not disk as such), which makes a dirty fs and invokes fsck
at reboot, right?
> > > however the impact of mfs (/var in particular) on upgrades has been
> > > quite painful,
> >
> > How?
> Losing new files in /var if the box is rebooted without first copying
> the /var (in memory) to where the persistent storage is (on shutdown)
Whht do you mean by "new files"? Those coming to exist
during regular operation (as in /var/run), or "new" if
they get installed under /var on an upgrade?
The above (losing the nonpersistent mfs storage) is exactly
what would happen on a power outage; but what does that have
to do with upgrades? If you reboot (cleanly) after an upgrade,
the content of /var gets stored to persitent storage.
> > > #cat /etc/fstab
> > > ff0023511d131fc2.a / ffs rw,softdep,noatime 1 1
> > > ff0023511d131fc2.b /usr/local ffs rw,wxallowed,nodev,softdep,noatime 1 2
> > > ff0023511d131fc2.d /var ffs rw,nodev,nosuid,softdep,noatime 1 2
> >
> > So you _don't_ have /var on mfs ...
> > Also, softdep no loger exists.
> Thanks it was an older option (now a noop (for backward compatibility
> ) just checked the manual there... Ill drop it off the deployment
> script
>
> > > swap /tmp mfs rw,nosuid,noexec,nodev,-s=262144,-P=/persist-fs/tmp 0 0
> > > swap /var/log mfs rw,nosuid,noexec,nodev,-s=524288,-P=/persist-fs/var/log
> > > 0 0
> > > swap /var/run mfs rw,nosuid,noexec,nodev,-s=262144,-P=/persist-fs/var/run
> > > 0 0
> > > swap /dev mfs rw,nosuid,noexec,-P=/persist-fs/dev,-i=2048,-s=32768 0 0
> >
> > Why do you need /tmp to persist?
> Fair point I was more interested in getting /tmp to be memory mounted
> (dont care about persistence) in that case
> checking manual
>
> > Why do you have a separate /dev?
> when programs write to /dev/blah is there a possibility of the
> filesystem being updated...
Above you talk about an upgrade, here about an update.
What you mean is just a write to the filesystem?
I never saw a / filesystem (holding /dev)
been screwed in a way that fsck couldn't get out of
because a file under /dev was being written ...
> > Why don't you have a separate /home?
> it is a router /firewall / network appliance /not a standard desktop
> / server ... users are admins... etc .
> >
> > > ###################################################
> > > This seems to solve problems with upgrades and package updates,
> basically if the partition was not synced with a copy on shutdown you
> would lose the updated files ...
Wll, you wouldn't have this problem
if you were not using mfs :-)
Filesystem inconsistency after a power outage is normal;
fsck will deal with it. You might lose some files -
with mfs, you lose everything.
Jan
