There are two ways to back up disks. After working with backups for a long time, I strongly feel that bru is much better than tar for large archives, such as backups. bru has better options for incremental backups and compresses files before archiving. However, bru does NOT append to a tape; if you use bru, then you CANNOT add to the tape at a later date. tar can append. Also, if a tape fails, the contents of the tape can often be salvaged up to the point where the tape is bad only if the tape is written in tar format---bad tapes written in bru format are garbage.

I've rewritten DAT.floater1 and DAT.nmr so that there are tar and bru options.

1. Run DAT.floater1 or DAT.nmr from an SGI. These programs have several options, including bru and tar, and a backup option for system administrators. It has been tested fairly thoroughly. You must run this interactively. Contact me if you want to use these programs to access other DAT drives; the two changes necessary are extremely simple.

---OR---

2. Run backup.full or backup.increment. These programs use BRU, no tar option is available. Directories and files are compressed and backed up. Links are backed up, but the file that the link points to is NOT backed up (unless it is also specified). These programs are in /local/info/backup AND /local/bin. If you routinely run these programs, copy them to /usr/local/bin (or perhaps /usr/local/backup) so that you avoid network problems. The programs do NOT have to be modified for a specific SGI. Jack Duan (Ellington/Daleke groups) has modified earlier versions of these programs; his programs have similar functionality and work very well.

To do a full backup, type:

/usr/local/bin/backup.full email_name /disk1 /disk2 /disk3 /disk4 /disk5 /disk6 /disk7 /disk8

Sub-directories can be specified instead of the entire disk. Up to 8 disks can be specified, at least 1 disk (or sub-directory) MUST be specified. For example:

/usr/local/bin/backup.full mpagel /usr/people /vxr400/data /etc

will back up three directories and all of their files and sub-directories and send email to mpagel@indiana.edu when it is done.

To do an incremental backup, type:

/usr/local/bin/backup.full month/day/year email_name /disk1 /disk2 /disk3 /disk4 /disk5...

Sub-directories can be specified instead of the entire disk. Up to 8 disks can be specified, at least 1 disk (or sub-directory) MUST be specified. For example:

/usr/local/bin/backup.full 2/7/95 mpagel /usr/people /vxr400/data /etc

will back up three directories and all of their files and subdirectories MODIFIED since 2/7/95 (including 2/7/95). It will then send email to mpagel@indiana.edu.

You CAN run these in background (add a & to the end of the commands listed above) and then log out. You can also use at to run these dommands at a later time. For example, type:

at 11:15pm Aug 23 <return>

/usr/local/bin/backup.full mpagel /usr/people <return>

<control-D>

to back up /usr/people and send email to mpagel@indiana.edu at 11:15pm August 23.

You can also automate backups with cron, but then you MUST remember to put the tape in the drive each week. I think it's safer to use at and then insert the tape.

Contact me at chemvis@indiana.edu for more info.