Mount agent notes
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Mount agent notes

The Mount agent has the following notes:

• High availability fire drill
• VxFS file system lock
• Support for loopback file system
• ZFS file system and pool creation example

High availability fire drill

The high availability fire drill detects discrepancies between the VCS configuration and the underlying infrastructure on a node; discrepancies that might prevent a service group from going online on a specific node. For Mount resources, the high availability drill performs the following, it:

• Checks if the specified mount point directory exists
• Checks if the mount point directory is already used
• Checks for valid Veritas (VxFS) file system licenses
• Checks if the mount point exists in the /etc/filesystems file

For more information about using the high availability fire drill see the Veritas Cluster Server Administrator's Guide.

VxFS file system lock

If the mount option in the mount table output has the option mntlock="key", then it is locked with the key "key". To verify if mount locking is in use and has the value of "key", run the mount command and review its output.

# mount

If the VxFS file system has mntlock="key" in its mount options, then unmounting the file system fails.

You can unlock the file system with the fsadm command and then unmount it. To unlock a locked mount, run the following command where "key" is the lock identifier and mount_point_name is the file system mount point.

# /opt/VRTS/bin/fsadm -o mntunlock="key" mount_point_name

To unmount a file system mounted with locking, run the umount command with the option mntunlock="key", for example:

# /opt/VRTS/bin/umount -o mntunlock="key" mount_point_name

Support for loopback file system

The Mount agent provides loopback file system support. You can manage the loopback file system as a Mount resource. You can use this loopback support to mount a file system in the global zone and share it in non-global zones. For loopback support, configure the FSType attribute to use a value of lofs.

Sample service group for the zone root on shared storage with a loopback file system when VCS manages the loopback file system as a Mount resource

Click the thumbnail above to view full-sized image.

The following is a sample configuration where you use the Mount resource to manage the lofs file system:

group loopbacksg (

SystemList = { sysA = 0, sysB = 1 }

ContainerInfo@sysA = { Name = zone1, Type = Zone, Enabled = 1 }

ContainerInfo@sysB = { Name = zone1, Type = Zone, Enabled = 1 }

)

Mount lofs_mnt_global_to_local (

MountPoint = "/export/home/zone1/root/lofs_mnt"

BlockDevice = "/mnt1/m1"

FSType = lofs

)

Zone z1 (

)

Mount base_mnt (

MountPoint = "/mnt1"

BlockDevice = "/dev/vx/dsk/tdg/tvol1"

FSType = vxfs

FsckOpt = "-y"

)

lofs_mnt_global_to_local requires z1

lofs_mnt_global_to_local requires base_mnt

ZFS file system and pool creation example

If you want to use the Mount resource to monitor the ZFS file system, perform the following steps.

Create the tank storage pool and file system on the disk device c1t0d0 for example.

# zpool create tank c1t0d0

Create the home file system in tank.

# zfs create tank/home

Set the value of the MountPoint attribute to legacy.

# zfs set mountpoint=legacy tank/home

Set the Mount agent's attributes. The following is an example of this configuration's main.cf file.

Mount m1 (

MountPoint = "/mp1"

BlockDevice = "tank/home"

FSType = zfs

MountOpt = rw

FsckOpt = "-n"

)