Red Hat Bugzilla – Bug 433702
nfs read-only root errors
Last modified: 2010-10-22 18:39:41 EDT
The following are a list of issues associated with a "stateless" read-only nfs
root disk. The test case was a diskless ppc blade, using a tmpfs RW_MOUNT and no
STATE_MOUNT. I have tested all of these changes on this test system but not on
any other architectures; however, I believe them to be generally applicable in
read-only nfs root configurations.
Changes to init scripts to better support stateless:
- don't update mtab in a r/o root
- mount on sys and /dev/pts returns EBUSY on a readonly root
- [ -n $CLIENTSTATE ] is always returning true, causing an unnecessary timeout
- /etc/mtab may not have any mount information in the readonly-root
cause, but the root mount is likely to be a network mount. Without
this, nfs hangs the reboot process.
- don't try and update a read-only mtab
- /var/empty/sshd/etc/localtime needs to be overwritten by sshd at
- /var/lib/random-seed is written to at shutdown; this fixes the
error but doesn't return the functionality lost in a r/o /var/lib.
Created attachment 295456 [details]
Created attachment 295457 [details]
network init patch
Created attachment 295458 [details]
Created attachment 295459 [details]
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release. Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products. This request is not yet committed for inclusion in an Update
Acking, but some of the patches need more investigation.
Regarding mount issue:
I believe other distributions have solved the mount/lockfile issue by using a
patched version of mount that doesn't create lockfiles in RO-root situations.
Since other tools/utilities might need information in /etc/mtab, I think it
might be more appropriate to symlink it to /proc/mounts. I noticed that the
netboot root preparation tool from Redhat appears to do this already.
Thanks for the patches Andrew!
please test http://people.redhat.com/harald/downloads/initscripts/initscripts-8.45.20-0.1.el5/
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.