[78] in Athena_Backup_System
downtime for the backup system
daemon@ATHENA.MIT.EDU (Diane Delgado)
Mon Feb 13 14:48:44 1995
To: athena-backup@MIT.EDU
Date: Mon, 13 Feb 1995 14:48:27 EST
From: Diane Delgado <delgado@MIT.EDU>
Here is some information from Brian and Richard about what
our current backup system is doing on a daily basis. For
lack of anything better, we can derive our first guestimate
regarding allowable downtime (for maintenance) per day or per week
for the new system from this information. (We assume that
the new system won't be slower than the current one).
We can also use some of this to determine the average
number of transactions per day for the database.
30,000 volumes on a 10 day cycle, roughly 3,000 volumes per day.
(not including weekends.)
10-12 hours for each backup
40 minutes for generation of volume list.
rest of time is spent doing actual backup.
backups usually start between 8-10 am and must finish by
about 10pm.
volume clone starts about 10pm and finishes by 7am. There isn't
any backup activity during this time.
Some things to think about:
When do we want to perform the sync up for an AFS server dumpset?
(e.g., during the 12pm to 7am time of the day before it is
backed up). This will impact the estimated number of
database transactions a day.
When do we want to perform the backup of the database itself and
how often? How long will this take?
