You lost what?!

Full and incremental backups are written to DDS-4 tapes in an HP autloader mechanism.

At 04:30 each day an "at" job starts the incremental backup on the tape which is in the drive. At the end of the backup a log of bytes written and errors is emailed. The DDS-4 tapes hold over 24GB of data, and the autoloader will change the incremental tapes when the backup software thinks it's within one incremental of the known limit.

While the most recent full and incrementals need to be on-site for restorations, the next most recent full backup and incremental set should be kept off-site, eg. at the system administrator's residence.

Backup software is GNU tar run from Perl scripts by Allan West, based on earlier works by Randy Fischer. The "Fischeresque" system was originally written for Mathematics, and updated at the Networked Writing Environment. Full backups are done on the directory /home/username/. and incrementals are done on files found to be newer than the last full backup.

For full backups use the most recent full in slot 1, which you can access by unloading the current tape and reloading tape 1 with the autoloader's mtx software:
mtx -d /dev/rmt/2cn -u # -l 1
you need to know the current #, which you can get from the autoloader's status message:
mtx -d /dev/rmt/2cn -s

Then you can get the file from tape:
cd /spool/backup.repo
tar -xvf /dev/rmt/2cn home/username/./file > full-log &
or the more extreme
tar -xvf /dev/rmt/2cn home/username > full-log &

then check the logs in /spool/backup.gtar for the file you need and insert the appropriate (eg. most recent) incremental tape.

Step forward to the right incremental file with asf (absolute space forward) and tar off the file
cd /spool/backup.repo/home
mt -f /dev/rmt/2cn asf 1
tar -xvf /dev/rmt/2cn username/file > ../../inc-log &


CLAS is moving to HP SureStore DDS-4 systems with an autoloader and single-tape unit. The DDS-4 system offers native 20GB capacity and up to 40GB with compression.

The autoloader will not automatically load the first tape when the cartridge is inserted. You will need to press the load button or use the mtx load command.

You can manually load a tape at the front panel or with the mtx command:
mtx -d /dev/rmt/2cn -l 1

To manually change tapes at the front panel:

Press the select button until it shows the number of the tape you want.	Press the load button.

Installation notes

The autoloader has an extra switch which needs to be set for Solaris:

Also, the following lines are necessary in the file /kernel/drv/st.conf:

# Copyright (c) 1995, by Sun Microsystems, Inc.
# All rights reserved.
## optional, use if needed:
#tape-driver-buffering = 4;
#
tape-config-list =
      "HP      HP35470A", "HP DDS 4mm DAT", "HP-data1",
      "HP      HP35480A", "HP DDS-DC 4mm DAT", "HP-data1",
      "HP      C1533A", "HP DDS2 4mm DAT", "HP-data2",
      "HP      C1537A", "HP DDS3 4mm DAT", "HP-data2",  
      "HP      C5683A", "HP DDS4 4mm DAT", "HP-data2",      
      "HP      C1553A", "HP DDS2 4mm DATloader", "HP-data2",
      "HP      C1557A", "HP DDS3 4mm DATloader", "HP-data2",
      "HP      C5713A", "HP DDS4 4mm DATloader", "HP-data2";
#      HP-data1 = 1,0x34,1024,0x639,3,0x00,0x13,0x3,2;
#      HP-data2 = 1,0x34,1024,0xd639,4,0x00,0x13,0x24,0x3,3;
## variable block size uses 0 instead of 1024
      HP-data1 = 1,0x34,0,0x639,3,0x00,0x13,0x3,2;
      HP-data2 = 1,0x34,0,0xd639,4,0x00,0x13,0x24,0x3,3;
## for single, included below
#name="st" class="scsi"
#        target=2 lun=0;
## for autoloader, included below
#name="st" class="scsi"
#        target=2 lun=0;
## for autoloader switching mechanism
name="st" class="scsi"
        target=4 lun=1;

Other modifications include putting all the users back on a single tape and then running the backup on tuna for testing.

Last modified: Mon Oct 16 11:47:59 EDT 2000