Installation and User's Guide

Syntax►► DISKBuffsize size ►◄ParameterssizeDiskcachelocationSpecifies the maximum disk I/O buffer size (in kilobytes) that the client useswhen reading files. The range of values is 16 through 1023; the default is 32.ExamplesOptions file:diskbuffsize 64Command line:Does not apply.The diskcachelocation option specifies the location where the disk cache databaseis created if the option memoryefficientbackup=diskcachemethod is set during anincremental backup.You can specify the diskcachelocation option in your option file, or with theinclude.fs option. If the diskcachelocation option appears in the option file, itsvalue is used for all file systems not represented by an include.fs option containingthe 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. Estimate 2 bytes per character in the path name. For example, if there are 1 000000 files and directories to be backed up and the average path length is 200characters, then the database occupies approximately 400 MB. Another way toestimate for planning purposes is to multiply the number of files and directoriesby the length of the longest path to establish a maximum database size.Supported ClientsThis option is valid for all clients. The server can also define this option.Options FilePlace this option in the client options file (dsm.opt).Chapter 12. Processing options 345