[SOLVED] 2.6.27 xfs root filesystem read only problem

Linux.tar.gz · 10-14-2008, 12:12 PM

Hi !

I upgraded my Slack 12.1 from 2.6.26.5 to 2.6.27, and my xfs / filesystem is now mounted as read-only because i have a read only error when i try to create something on it.

Weird thing : mount and cat /proc/mounts shows / is rw !!!

Wrong kernel (security) settings or new parameter missing ?

Witi · 10-15-2008, 01:08 AM

Hi.

Same problem here with Archlinux. E.g. I can create a directory, but can't do a chmod on it. And on boot many commands fail.

But it only concerns the root partitions, other xfs partitions with the same mount options are working.
I'm using the following mount options:

Code:

/dev/sda2 / xfs defaults,noatime,nodiratime,logbufs=8,nobarrier 0 1

Today I played a bit with the options and found a workaround. I removed all options except for defaults. After a reboot I had write access.

There is another problem with xfs, barriers handling in 2.6.27, but i think we discovered here something else.

Witi

namor · 10-16-2008, 04:21 AM

Same problem here.
I use the same mount options as Witi, but "nobarrier" is missing.

Quote:

Originally Posted by Witi

Today I played a bit with the options and found a workaround. I removed all options except for defaults. After a reboot I had write access.
Witi

The workaround works for me too; thanks!

Linux.tar.gz · 10-16-2008, 02:19 PM

Be careful ! nobarrier is _not_ for production use. It makes xfs approx. 10 times faster, but any powerdown can corrupt the whole filesystem.

Stay tuned.

Witi · 10-17-2008, 06:04 AM

http://bugs.archlinux.org/task/11765

In Archlinux this bug seems to be fixed with the new kernel version 2.6.27.1. I can confirm this.

Quote:

Be careful ! nobarrier is _not_ for production use. It makes xfs approx. 10 times faster, but any powerdown can corrupt the whole filesystem.

no risk no fun.

No, you are right. But in production you should an UPS to prevent every powerdown.

Linux.tar.gz · 10-19-2008, 06:42 AM

Production means "non-experimental use", not exclusively "server use".
2.6.27.2 seems to fix our problem. Let's test !

Linux.tar.gz · 10-19-2008, 02:52 PM

Arr... don't works ! Always read-only.
It said /dev/tty not found.

Linux.tar.gz · 10-24-2008, 07:03 PM

2.6.27.3 solved this issue.
Thanks all, and thanks to kernel developers :^).

Linux.tar.gz · 02-11-2009, 04:16 AM

And now, with approx. 9 monthes testing, i can tell you that : don't use XFS on a workstation. This filesystem is too slow. I'm sure it rocks handling 1+ Tera files, but it's a pain on a desktop. I switched back to ext3/Reiserfs combo, et voila.

Witi · 02-12-2009, 12:20 AM

Well using the standard settings could be slower than other filesystem. Did you try to "tune" it?

Linux.tar.gz · 02-12-2009, 02:50 AM

Yes i did, resulting 50% of our computers unusable in case of crash or power failure :^D.