UNIVERSITY OF CALIFORNIA OBSERVATORIES / LICK OBSERVATORY

System Backups with the 115 Gb FireWire Drive HOME

System backups for all machines are now being done with a 115 Gb firewire hard drive (actually two that are rotated weekly). Weekly updates are performed by cron job which backups half the machines on Saturday morning, the remaining half on Sunday.

Backups for each machine are numbered; earlier backups are retained. Thus, after a few weeks, you'll see backup.0, backup.1, backup.2, and so on. (In fact, only new files, or files that have changed since the last backup, are actually written to the new backup. Unchanged files are represented as hard links to an earlier backup. This is invisible to the user, however, and each backup will show the complete file system.)

Backups will not be kept indefinitely, however. The disks are expected to fill up in about one year, at which time they will overwritten.


The filesystems that are backed up are:

/usr/local/lick
/usr/local/music
/u
/var/www


To look at the backup:

log on to bernard as root and cd to /mnt/firewire1

ls lists all machines backed up (mtham ettin catpc ...)

cd to the machine of your choice

ls lists backups for that machine (backup.0 backup.1 ...)

highest number is most recent

cd to the most recent backup

ls lists the filesystems (lick music u www)


If you should need to swap disks yourself (the one not mounted will be kept at the 3-meter), log on to bernard as root, cd to /, and unmount the current disk by typing:

umount firewire1

swap the disks on bernard, and mount the new one by typing:

mount /dev/sda1 /mnt/firewire1


Last update: 5 March, 2003, T.M.