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

ParameterssizeDiskcachelocationSpecifies the maximum disk I/O buffer size (in kilobytes) that the client willuse when reading files. The range of values is 16 through 1023; the default is32. For AIX: If the enablelanfree option is set to no, the default setting fordiskbuffsize is 256.ExamplesOptions file:diskbuffsize 64Command line:Does not apply.The diskcachelocation option specifies the location where the disk cache databasewill be created if the option memoryefficientbackup=diskcachemethod is set duringan incremental backup. You can specify the diskcachelocation option in youroption file, or with the include.fs option. If the diskcachelocation option appears inthe option file, its value will be used for all file systems not represented by aninclude.fs option containing the diskcachelocation option.You must be an authorized user to use the diskcachelocation option.The disk cache is a temporary file which is deleted after the incremental commandis run. Use this option to select one of the following:1. A location that has more free disk space if, when you are usingmemoryefficientbackup=diskcachemethod, you get the message that the diskcache file cannot be created because you do not have enough disk space.2. A location on a different physical volume to reduce contention for the diskaccess mechanism, and therefore improve performance.Important: For performance reasons, do not use a remote drive fordiskcachelocation.The actual amount of disk space required for the disk cache file created by diskcache incremental backups depends on the number of files and directories includedin the backup and on the average length of the files and directories to be backedup. For UNIX and Linux, estimate 1 byte per character in the path name. For MacOS X, estimate 4 bytes per character in the path name. For example, if there are 1000 000 files and directories to be backed up and the average path length is 200characters, then the database will occupy approximately 200 MB for UNIX andLinux, and 800 MB for Mac OS X clients. Another way to estimate for planningpurposes is to multiply the number of files and directories by the length of thelongest path to establish a maximum database size.A second disk cache file is created for the list of migrated files when backing up anHSM managed file system. The combined disk cache files, created by disk cacheincremental backups and HSM managed file system backups, can require above400 MB of disk space for each million files being backed up.Supported ClientsThis option is valid for all clients. The server can also define this option.Chapter 10. Using processing options 295