3.5.1 Matrix Server Administration Guide

Chapter 7: Configure PSFS Filesystems 123

Suspend a Filesystem for Backups

The psfssuspend utility suspends a PSFS filesystem in a stable, coherent,

and unchanging state. While the filesystem is in this state, you can copy it

for backup and/or archival purposes. When copying directly from a

suspended device, be sure to use the raw device (/dev/rpsd/...) to ensure

that all of the copied blocks are up-to-date.

The filesystem is essentially unusable while it is suspended; however,

applications that can tolerate extended waits for I/O do not need to be

terminated.

The psfsresume utility restores a suspended filesystem. The psfssuspend

and psfsresume utilities affect the specified filesystem on all servers

where it is mounted; however, the utilities should be executed on only

one server in the matrix.

To suspend a filesystem, issue the following command on one server that

has mounted the filesystem. You must be user root.

# /opt/polyserve/tools/psfssuspend directory_mountpoint

The psfssuspend command prevents modifications to the filesystem and

forces any changed blocks associated with the filesystem to disk. The

command performs these actions on all servers that have mounted the

filesystem and then returns successfully.

Any process attempting to modify a suspended filesystem will block

until the filesystem is resumed. These blocked processes may hold

resources, thereby causing other processes to block waiting on these

resources.

When you have completed the backups, use the psfsresume utility to

resume the suspended filesystem. Issue the command from the server

where you executed psfssuspend. You must be user root.

# /opt/polyserve/tools/psfsresume directory_mountpoint