IBM Tivoli Storage Manager for UNIX and Linux Backup-Archive ...

Snapshotcachesizeincremental -snapdiff -diffsnapshot=latest /net/home1Related information“Diffsnapshot” on page 291“Set Password” on page 529Use the snapshotcachesize option to specify an appropriate size to create thesnapshot.The size estimation is needed for storing the original data blocks for modified anddeleted data for the point in time when the snapshot was taken.For snapshot-based file backup or archive, use the snapshotcachesize option withthe include.fs option, or in the server stanza in the dsm.sys file.For snapshot-based image backups, use the snapshotcachesize option with thebackup image command, the include.image option, or in your dsm.sys file.Supported ClientsThis option is valid for AIX and Linux clients only. The Tivoli Storage Managerclient API does not support this option. The server can also define this option.Options FilePlace this option in the server stanza in the dsm.sys file. You can set this option onthe Image-Snapshot tab of the Preferences editor.Syntax►► SNAPSHOTCACHESize size ►◄ParameterssizeSpecifies an appropriate size to create the snapshot for storing the original datablocks for modified and deleted data for the point in time when the snapshotwas taken. The value is the percent of the file system size that is changed dueto file system activity. The range of values is 1 to 100 percent. For AIX JFS2and Linux the default value is 100 percent of the file system size. If a sufficientamount of free space is not available to create the snapshot, the command willfail with an error message. You can then either increase the size of the volumegroup or retry the operation. If based on your experience with your AIX JFS2file system activity, you find that a snapshot size of 100 percent is notnecessary, you can fine-tune the value.AIX only: If you have enabled snapshot-based file backup or archive orsnapshot-based image backup for your JFS2 file system and you expect a lot offile system activity such as creation, modification and deletion of files (inparticular, deletion of large files or a large number of files), then make surethat you set the snapshotcachesize greater than the default, which is 20 percentof your file system size. For example, if you are deleting one or more files that402 IBM Tivoli Storage Manager for UNIX and Linux Backup-Archive Clients Version 6.1: Installation and User’s Guide