Veritas File System 5.0 AdministratorÆs Guide, HP-UX 11i v3, First Edition, May 2008

Removable Storage Checkpoints

A removable Storage Checkpoint can “self-destruct” under certain conditions

when the file system runs out of space.

See “Space management considerations” on page 94.

After encountering certain out-of-space (ENOSPC) conditions, the kernel removes

Storage Checkpoints to free up space for the application to continue running on

the file system. In almost all situations, you should create Storage Checkpoints

with the removable attribute.

Non-mountable Storage Checkpoints

You can create Storage Checkpoints that cannot be mounted by using the

fsckptadm set nomount command.

See the fsckptadm(1M) manual page.

Use this type of Storage Checkpoint as a security feature which prevents other

applications from accessing the Storage Checkpoint and modifying it.

Storage Checkpoint administration

Storage Checkpoint administrative operations require the fsckptadm utility.

See the fsckptadm(1M) manual page.

You can use the fsckptadm utility to create and remove Storage Checkpoints,

change attributes, and ascertain statistical data. Every Storage Checkpoint has

an associated name, which allows you to manage Storage Checkpoints; this name

is limited to 127 characters and cannot contain a colon (:).

Storage Checkpoints require some space for metadata on the volume or set of

volumes specified by the file system allocation policy or Storage Checkpoint

allocation policy. The fsckptadm utility displays an error if the volume or set of

volumes does not have enough free space to contain the metadata. You can roughly

approximate the amount of space required by the metadata using a method that

depends on the disk layout version of the file system.

For disk layout Version 5 or prior, multiply the number of inodes (# of inodes) by

the inode size (inosize) in bytes, and add 1 or 2 megabytes to get the approximate

amount of space required. You can determine the number of inodes with the

fsckptadm utility, and the inode size with the mkfs command:

# fsckptadm -v info '' /mnt0

UNNAMED:

Storage Checkpoints

Storage Checkpoint administration