The backup system is based on a set of scripts in
/data/elixir2/datdir/backup. There is a perl script 'backup' which
does the actual backup management, and there is a table 'backup.tab'
which defines the relationships between the disk partitions. The
script is run by a cronjob, which should be run as user 'ptolemy2' so
there will not be ownership conflicts (or root?).
The backup.tab has entries of the form:
# /data/elixir
TARGET elixir
SOURCE uhane:/local/data/elixir
MIRROR mamane:/local/data/mamane/elixir.mirror
DIR detrend
DIR tests
end
This defines the abstract target name (arbitrary), the source and
mirror machines and partitions, and the directories in that partition
to backup (this allows us to exclude certain directories). Here is a
summary of the backup command:
naio: backup
USAGE: backup.exe (command) [target]
backup -targets : list available targets
backup -status (target) : list settings for target
backup -backup (target) : copy data from disk to mirror
backup -restore (target) : restore mirror to disk
backup -check (target) : restore mirror to disk
To get a listing of available targets:
naio: backup -targets
available targets:
elixir
elixir1
elixir2
elixir3
skyprobe
noni
To check the backup configuration for a given target:
naio: backup -status elixir
target: elixir
source: uhane:/local/data/elixir
mirror: mamane:/local/data/mamane/elixir.mirror
dir: detrend
dir: tests
the crontab file shows the backup command in action doing a backup,
for example:
backup -backup elixir2
The elixir partitions are defined in pairs with names like:
naio:/data/naio/elixir2.mirror
naupaka:/data/naupaka/elixir2.mirror
One of these (the SOURCE entry above) gets mapped to /data/elixir2 in
the automount system. The theory is that a partition goes down, you
restore it, then run backup -restore (target) to recover the data. In
practice, we almost never use the -restore command. We've instead
switched the automount points to point at the MIRROR and switched the
entries in the backup.tab between MIRROR and SOURCE. Be very careful!
Note that the backup -backup command explicitly requests for
deletion of data from the MIRROR that is not on the SOURCE! It has to
do this, because it has to keep up with valid deletions. This means
if you get these confused, you can lose data.
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