SUL/AIR Unicorn Backup Schedule

This note provides more information about our weekly backup schedule.

We do a disk-to-disk copy of the directory containing our Unicorn data starting at 10 PM Saturday while the system is running. Copying of 35 GB takes us 6 hours. We do a halt of Unicorn at 4AM Sunday, then use the Unix find command to identify files which have been modified since backup was begun:

find $subdirectory -type f -newer $timestamp.file >> $recopy.list

We then recopy just the files that have changed. Because there is little activity and we run no reports that modify bibliographic data, the recopy of changed files goes quickly. (But we allow an hour's time in case). Next day there is an ADSM backup of the database copy.

We reserve the 5AM-8AM Sunday time slot for AIX & hardware maintenance and keep Unicorn halted whether maintenance is required or not. We also reserve the right to halt Unicorn 5-7 AM Thursday and 5-8 AM Saturday.