Re: Debian: readonly root filesystem using /dev/root

propman wrote:

Tim Greer wrote:
Mark Hobley wrote:

Hmmm, I am seeing something really strange on one of my Debian
systems (using Debian Testing / Lenny) , and I just wondered if
anyone else is seeing this.

My root filesystem had for some reason been mounted readonly. This
was reported to me as I tried to upgrade some packages.

I thought to myself "No problem. I will remount the filesystem for
read and write access."

I first checked that the filesystem was mounted readonly, because I
was not expecting this to be so:

cat /proc/mounts

/dev/root / ext2 ro,errors=remount-ro 0 0

Hmmm, it is readonly.

I remounted this:

mount -o remount,rw /

Right, that should have fixed this.

cat /proc/mounts

/dev/root / ext2 rw,errors=remount-ro 0 0

Ok, I created a test file:

echo hello > /root/test.fil

(Ony my system /root is the home directory for the root user, and is
on the root filesystem.)

sh: cannot create /root/test.fil: Read-only file system

Huh? The disk appears to still be readonly.

Right before a drive starts to die, it will sometimes start setting
the
root partition to read only. Check dmesh, your messages log, run
smart
drive tools and see if there are any errors reported. Either way,
ensure you have up to date and complete backups, regardless if you
find errors, because it probably has a matter of hours or days before
data starts being shown as unreadable (to even copy/backup) from that
drive.


FWIW.....suggest you also log onto the drive manufacturer's web site
to see if they have a low-level testing utility; if so, it should give
you a definitive answer whether the disk is dying or not.

Again FWIW, ran across this link the other day (haven't had a chance
to download and try it out yet though):

www.ultimatebootcd.com

The website states that amongst other rescue utilities, it also
includes low-level testing programs from several of the hard drive
manufacturers.

Good points. Also, if you feel the drive is going, the best thing to do
it to boot into single user mode and do the work there (less
processing, reading and writing, the better) and back up the data that
way (hopefully you have current backups anyway, as anyone should).
However, with the tools on a system that's already booted up and
running, you should have a good indication pretty quick of a problem
without a drive manufacturer utility if the drive is failing and is
already at the point where it's mounting / as ro.
--
Tim Greer, CEO/Founder/CTO, BurlyHost.com, Inc.
Shared Hosting, Reseller Hosting, Dedicated & Semi-Dedicated servers
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Relevant Pages

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    (comp.os.linux.misc)
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    ... in other words, again root is compromised. ... That means that in a standard config the root filesystem cannot be made ... backup, and fewer writes means less likelihood of corruption eg if power ... Note that all my live partitions are rsync'd with identical ...
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  • Re: Read-only root (/) except /et
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    (Debian-User)
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