http://support.veritas.com/docs/192620

How to disable and re-enable VXVM at boot when the boot disk is encapsulated ( Not Removing any Disk )

At times it may be necessary for debugging and/or other reasons to boot a system without starting VERITAS Volume Manager (VxVM). This is sometimes referred to as "manually unencapsulating" if the boot disk is involved. The following are the basic steps needed to disable VxVM with an encapsulated boot disk: IMPORTANT: If rootvol, usr, or var volumes are mirrored, all mirrors except for the one on the boot disk will have to be disabled before enabling VxVM once again (see below for details). Failure to do so may result in file system corruption. 1. Boot system from CD ROM or net and mount the root file system to /a 2. Modify the vfstab file. a. Make a backup copy:

# cp /a/etc/vfstab /a/etc/vfstab.disable b. Use the preserved copy of the vfstab file from before encapsulation as base for the new file:

# cp /a/etc/vfstab.prevm /a/etc/vfstab c. Verify that the Solaris file system partitions listed in /a/etc/vfstab are consistent with the current boot drive and that the partitions exist. Note: Usually the partition for the /opt file system will not be present. It is not needed to bring the system up to single user mode. d. Comment out any entries referring to VxVM volumes from /a/etc/vfstab. 3. Modify the system file. a. Make a backup copy:

# cp /a/etc/system /a/etc/system.disable b. Delete the following lines from /a/etc/system:

rootdev:/pseudo/vxio@0:0 set vxio:vol_rootdev_is_volume=1

c. The force loads for VxVM drivers (vxio, vxspec, and vxdmp) may also be deleted, but that is not usually necessary. 4. Create a file called /a/etc/vx/reconfig.d/state.d/install-db. This prevents VxVM from starting during the boot process.

# touch /a/etc/vx/reconfig.d/state.d/install-db 5. Reboot from the disk that was just modified. 6. Once the system is booted in at least single-user mode, VxVM can be started manually with the following steps.

a. Start the VxVM worker threads:

# vxiod set 10 b. Start vxconfigd in disabled mode:

# vxconfigd -d

c. Enable vxconfigd:

# vxdctl enable

At this point the rootdg disk group should be imported and all volumes should be in DISABLED state. d. IMPORTANT: If the boot disk contains mirrored volumes, one must take all the mirrors offline for those volumes except for the one on the boot disk. Offlining a mirror prevents VxVM from ever performing a recovery on that plex. This step is critical in preventing data corruption. For example, if the boot disk is c0t0d0 with a vxprint output as follows:

# vxprint -htg rootdg ... v rootvol root DISABLED ACTIVE 1026000 PREFER rootvol-01 pl rootvol-01 rootvol DISABLED ACTIVE 1026000 CONCAT - RW sd rootdisk-B0 rootvol-01 rootdisk 8378639 1 0 c0t0d0 ENA sd rootdisk-02 rootvol-01 rootdisk 0 1025999 1 c0t0d0 ENA pl rootvol-02 rootvol DISABLED ACTIVE 1027026 CONCAT - RW sd rootmir-06 rootvol-02 rootmir 0 1027026 0 c0t1d0 ENA ...

In this case the rootvol-02 plex should be offlined as it resides on c0t1d0: # vxmend -g rootdg off rootvol-02

e. Start all volumes( Not using vxstart , but vxrecover)

# vxrecover -ns f. Start any recovery operations on volumes if needed:

# vxrecover -bs Once any debugging actions and/or any other operations are completed, VxVM can be re-enabled again with the following steps.

***

1. Undo the steps in the previous section that were taken to disable VxVM (steps 2-4): # cp /etc/vfstab.disable /etc/vfstab # cp /etc/system.disable /etc/system # rm /etc/vx/reconfig.d/state.d/install-db

2. Reboot the system. 3. Once the system is back up and it is verified to be running correctly, online all mirrors that were offlined in step 6 in the previous section. For example,

# vxmend -g rootdg on rootvol-02 4. Start recovery operations on the mirrors that were just onlined.

# vxrecover -bs

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