March 6, 2007 : nixCraft FAQ Roundup

Posted on in Categories FAQ last updated March 6, 2007

Recently updated/posted Linux and UNIX FAQ:

Solaris tar command to backup data on tape device

Posted on in Categories Howto, Solaris, Sys admin, Tips, UNIX last updated March 22, 2005

Tar name come from Tape ARchiver. It is both a file format and the name of the program used to handle such file. Tar archive files have names ending in “.tar”. If an archive is compressed, the compression program adds its own suffix as usual, resulting in filename endings like “.tar.Z”, “.tar.gz”, and “.tar.bz2”. Tar doesn’t require any particular filename suffix in order to recognize a file as an archive. Tar was originally created for backups on magnetic tape, but it can be used to create tar files anywhere on a filesystem. Archives that have been created with tar are commonly referred to as tarballs.

Create a new set of backup

To create a Tar file, use tar command as follows:
# tar cvf /dev/rmt/X file1 file2 dir1 dir2 file2 …

  • c – Create a new files on tape/archive
  • v – verbose i.e. show list of files while backing up
  • f – tape device name or file

For example, backup /export/home/vivek/sprj directory to tape device /dev/rmt/0, enter
# tar cvf /dev/rmt/0 /export/home/vivek/sprj/
Remember c option should only use to create new set of backup.

Appending or backing up more files to same tape using tar

tar provides r option for appending files to tape. For example to backup /data2/tprj/alpha1 files to same tape i.e. appending files to a first tape device:
# tar rvf /dev/rmt/0 /data2/tprj/alpha1/*

  • r – append files to the end of an archive/tape

List files on a tape using tar command

To display file listing of a first tape use tar as follows:
# tar tvf /dev/rmt/0
To listing the Contents of a Stored Directory (for example wwwroot directory):
# tar tvf /dev/rmt/0 wwwroot

  • t – list the contents of an archive/tape

Retrieve / restore tape backup taken with tar

1) Use tar command as follows to retrieve tape drive backup to current directory:
(a) Change directory where you would like to restore files:
# cd /path/to/restore
# pwd

(b) Now, do a restore from tape:
# tar xvf /dev/rmt/0

To specify target directory use –C option

Restore everything to /data2 directory:
# tar xvf /dev/rmt/0 –C /data2
To retrieve directory or file use tar as follows:
# tar xvf /dev/rmt/0 tprj
Note that Solaris tar command is little different from GNU tar, if you wish to use gnu tar with Solaris use command gtar. Gnu tar accepts same command line options plus bunch of additional options 🙂

See Sun Solaris tar man page and tapes ~ creates /dev entries for tape drives attached to the system.