The patch history is a record of information about patches installed with the patch installer or the LSF installer, including products and patches installed, dates, and location of backups required for rollback purposes.
The pversions command retrieves and displays the version information. The patch installer rollback feature retrieves the backup information.
The patch history information is kept in the patch history directory. The directory location is LSF_TOP/patch by default.
The patch history directory is configurable during installation. See the PATCH_HISTORY_DIR parameter in install.config.
The patch installer backs up the current installation before attempting to replace files with the newer versions. The backups are saved so that rollback is possible later on.
Patches change relatively few files, but for an update release, all the files in the cluster are backed up, so the amount of space required is large. The more patches you install, the more space is required to save multiple backups.
The patch backup files are kept in the patch backup directory. The directory location is LSF_TOP/patch/backup by default.
The patch backup directory is configurable during installation. See the PATCH_BACKUP_DIR parameter in install.config.
Over time, the backups accumulate. You may choose to manually delete old backups, starting with the oldest. Remember that rollback is performed one patch at a time, so your cluster’s rollback functionality stops at the point where a backup file is unavailable.
If the backup directory runs out of space, your installations and rollbacks fail.
You can change your backup directory by setting PATCH_BACKUP_DIR in patch.conf, but you must copy the contents of the old directory to the new directory manually (or there can be no rollback).
You can disable backups when installing update releases. In this case, your update is installed without backing up the cluster first, so you cannot remove the update using the rollback functionality.
You might choose this feature to save disk space to speed up the install process, or if you have your own methods of backing up the cluster.
Backup is always done before installing fixes, so you can always roll back if a fix does not behave as expected.
To make changes without affecting running daemons, the patch installer must move some files to another directory instead of overwriting.
For each file, a new directory is created in parallel with the file. The directory is called daemons_old.
Running jobs may require the old files even after you restart the updated cluster.