Managing Serviceguard 14th Edition, June 2007

Building an HA Cluster Configuration
Creating a Storage Infrastructure with Veritas Cluster File System (CFS)
Chapter 5252
Creating Checkpoint and Snapshot Packages for CFS
The storage checkpoints and snapshots are two additional mount point
package types. They can be associated with the cluster via the
cfsmntadm(1m) command.
Mount Point Packages for Storage Checkpoints
The Veritas File System provides a unique storage checkpoint facility
which quickly creates a persistent image of a filesystem at an exact point
in time. Storage checkpoints significantly reduce I/O overhead by
identifying and maintaining only the filesystem blocks that have
changed since the last storage checkpoint or backup. This is done by a
copy-on-write technique. Unlike a disk-based mirroring technology,
which requires a separate storage space, this Veritas technology
minimizes the use of disk space by creating a storage checkpoint within
the same free space available to the filesystem.
For more information about the technique, see the Veritas File System
Administrator’s Guide appropriate to your version of CFS, posted at
http://docs.hp.com.
The following example illustrates how to create a storage checkpoint of
the /cfs/mnt2 filesystem.
Start with a cluster-mounted file system.
1. Create a checkpoint of /tmp/logdata/log_files named check2. It
is recommended that the file system already be part of a mount point
package that is mounted.
cfsmntadm display
Cluster Configuration for Node: ftsys9
MOUNT POINT TYPE SHARED VOLUME DISK GROUP STATUS
/tmp/logdata/log_files regular log_files logdata MOUNTED
Cluster Configuration for Node: ftsys10
MOUNT POINT TYPE SHARED VOLUME DISK GROUP STATUS
/tmp/logdata/log_files regular log_files logdata MOUNTED
fsckptadm -n create check2 /tmp/logdata/log_files
2. Associate it with the cluster and mount it.
cfsmntadm add ckpt check2 /tmp/logdata/log_files \
/tmp/check_logfiles all=rw