UFS logging enabled on an encapsulated rootdisk may result in warnings and errors, and may lead to system panics and an unbootable system.

Article:TECH34323  |  Created: 2004-01-14  |  Updated: 2005-01-02  |  Article URL http://www.symantec.com/docs/TECH34323
Article Type
Technical Solution

Product(s)

Environment

Issue



UFS logging enabled on an encapsulated rootdisk may result in warnings and errors, and may lead to system panics and an unbootable system.

Solution



UFS logging is a UFS file system feature that records file system transactions to a log before applying it to the file system itself.  UFS logging is enabled by default starting with Solaris 9 Update 7 or with Patch 113073-09.

In a VERITAS Volume Manager configuration, if the root volume is encapsulated, then the root (/) and user (/usr) file systems are not writeable during the early stages of the boot process, when these file systems are being mounted.  As a result, UFS logging will fail. Thus, if UFS logging is enabled on an encapsulated rootdisk, the system may
- generate the following error messages:
Oct 14 22:30:14 stsunprod3 ufs: [ID 702911 kern.warning] WARNING: Error writing ufs log state
Oct 14 22:30:14 stsunprod3 ufs: [ID 127457 kern.warning] WARNING: ufs log for / changed state to Error
Oct 14 22:30:14 stsunprod3 ufs: [ID 616219 kern.warning] WARNING: Please umount(1M) / and run fsck(1M)
- fail to boot, and/or
- result in a panic (panic string is "vfs_mountroot: cannot mount root").

File systems such as  /opt and /var which may reside on the root volume are not affected.

To work around this issue, disable UFS logging on /, /usr and the swap volume prior to root encapsulation by editing the /etc/vfstab file, and adding the "nologging" flag in the mount option field of the appropriate entries:

/dev/vx/dsk/bootdg/rootvol   /dev/vx/rdsk/bootdg/rootvol  /    ufs  1 no nologging
/dev/vx/dsk/bootdg/usr       /dev/vx/rdsk/bootdg/usr     /usr  ufs  1 no nologging
/dev/vx/dsk/bootdg/swapvol      -       -       swap    -       no nologging

The swap volume is a special case where UFS logging should be explicitly disabled. If /usr is not a separate volume, then there will not be an entry for it in /etc/vfstab.  A reboot is necessary after the above changes are made.

The following two patches, in addition to the 4.1 release,  will automatically add the "nologging" option to the / and /usr entries in /etc/vfstab file during root encapsulation:

VERITAS Volume Manager 4.0 MP1 Point Patch 4.3 (117078-04)
VERITAS Volume Manager 3.5 MP3 Point Patch 3.2 (116697-05)

You will still need to manually add the "nologging" option to the swap volume.

The complete fix, allowing UFS logging to be enabled on encapsulated disks, will be incorporated in VERITAS Volume Manager 4.0 MP2 (release slated for mid-June, 2005) and 4.1 MP1 (release schedule to be determined).  For Volume Manager 3.5 MP3, Point Patch 5.2 (Sun Patch ID 116697-08) is available to address this issue.  Please contact VERITAS Technical Support if you need this patch.

The companion Sun document is Sun Alert 57636.


Supplemental Materials

SourceETrack
Value259150
DescriptionNeed to automatically mark the root volume to "nologging" (in /etc/vfstab) during root encapsulation

SourceETrack
Value258147
DescriptionUFS logging error on VM encapsulated disk

SourceSun BugId
Value5045578
Descriptionpersistent warning messages after encapsulating root logging disk

Legacy ID



271404


Article URL http://www.symantec.com/docs/TECH34323


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