[LU-1203] When upgrading from Lustre 1.8 to 2.1, if the parameter root_squash is set, Lustre throws an error and denies mounting the filesystem. It's necessary to completely delete the parameter

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.3.0, Lustre 2.4.0, Lustre 2.1.4
• Affects Version/s: Lustre 2.1.0, Lustre 2.2.0, Lustre 2.3.0, Lustre 2.1.2
• Labels: migration root_squash, writeconf
• Environment: Scientific Linux 5.5 (servers), Scientific Linux 5.5 & 6.2 (clients)
• Severity: 3
• Assignee: Jian Yu
• Reporter: Antonio Sanz

Description

When upgrading from Lustre 1.8 to 2.1, if the parameter rootsquash is set, Lustre throws an error and denies mounting the filesystem. This is the error from the MDS logs:

Mar 7 20:03:35 mds01 kernel: LustreError: 6610:0:(obd_config.c:1140:class_process_proc_param()) home-MDT0000: unknown param rootsquash=99:99
Mar 7 20:03:35 mds01 kernel: LustreError: 6610:0:(obd_config.c:1361:class_config_llog_handler()) Err -38 on cfg command:
Mar 7 20:03:35 mds01 kernel: Lustre: cmd=cf00f 0:home-MDT0000 1:mdt.rootsquash=99:99
Mar 7 20:03:35 mds01 kernel: LustreError: 15c-8: MGC172.16.4.3 at tcp: The configuration from log 'home-MDT0000' failed (-38). This may be the result of communication errors between this node and the MGS, a bad configuration, or other errors. See the syslog for more information.
Mar 7 20:03:35 mds01 kernel: LustreError: 6124:0:(obd_mount.c:1192:server_start_targets()) failed to start server home-MDT0000: -38
Mar 7 20:03:35 mds01 kernel: LustreError: 6124:0:(obd_mount.c:1723:server_fill_super()) Unable to start targets: -38
Mar 7 20:03:35 mds01 kernel: Lustre: Failing over home-MDT0000

We were able to overcome this using tunefs.lustre with the option --writeconf added. This should be managed automatically (ideally, migrating the configuration) or at least, documented.

Issue Links

• is related to: LU-2308 class_process_config() prints confusing warnings, is confusing
• Trackbacks: Changelog 2.1 Changes from version 2.1.2 to version 2.1.3 Server support for kernels: 2.6.18308.13.1.el5 (RHEL5) 2.6.32279.2.1.el6 (RHEL6) Client support for unpatched kernels: 2.6.18308.13.1.el5 (RHEL5) 2.6.32279.2.1....