backup(1M)

NAME

backup — backup or archive file system

SYNOPSIS

/usr/sbin/backup [-A] [-archive] [-fsck]

DESCRIPTION

The backup command uses find(1) and cpio(1) to save a cpio archive of all files that have been modified since the modification time of /var/adm/archivedate on the default tape drive (/dev/update.src). backup should be invoked periodically to ensure adequate file backup.

The -A option suppresses warning messages regarding optional access control list entries. backup(1M) does not backup optional access control list entries in a file's access control list (see acl(5)). Normally, a warning message is printed for each file having optional access control list entries.

The -archive option causes backup to save all files, regardless of their modification date, and then update /var/adm/archivedate using touch(1).

backup prompts you to mount a new tape and continue if there is no more room on the current tape. Note that this prompting does not occur if you are running backup from cron(1M).

The -fsck option causes backup to start a file system consistency check (without correction) after the backup is complete. For correct results, it is important that the system be effectively single-user while fsck is running, especially if -fsck is allowed to automatically fix whatever inconsistencies it finds. backup does not ensure that the system is single-user.

You can edit /usr/sbin/backup to customize it for your system. Several local values are used that can be customized:

BACKUPDIRS: specifies which directories to back up recursively (usually /, meaning all directories);
BACKUPLOG: file name where start and finish times, block counts, and error messages are logged;
ARCHIVE: file name whose date is the date of the last archive;
REMIND: file name that is checked by /etc/profile to remind the next person who logs in to change the backup tape;
FSCKLOG: file name where start and finish times and fsck output is logged.

You may want to make other changes, such as whether or not fsck does automatic correction (according to its arguments), where cpio output is directed, other information logging, etc.

In all cases, the output from backup is a normal cpio archive file (or volume) which can be read using cpio with the c option.

File Recovery

backup creates archive tapes with all files and directories specified relative to the root directory. When recovering files from an archive tape created by backup, you should be in the root directory and specify the directory path names for recovered files relative to the root directory (/). When specifying the directory path name for file recovery by cpio, do not precede the leading directory name with a slash. If you prefer, you can also use cpio with a -t option to determine how files and directories are named on the archive tape before attempting recovery.

WARNINGS

Refer to WARNINGS in cpio(1).

When cpio runs out of tape, it sends an error to standard error and demands a new special file name from /dev/tty.

To continue, rewind the tape, mount the new tape, type the name of the new special file at the system console, and press Return.

If backup is being run unattended from cron(1M) and the tape runs out, backup terminates, leaving the find process still waiting. Kill this process when you return.

FILES

/var/adm/archivedate: parameterized file names

backup(1M)

Technical documentation

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