Hi there,
as Kurt mentioned, you must make sure that your IT folks/Sys admins have a proper backup
in place that includes the SAS environment.
Some documentation and best practices for backups:
About Backup and Restores
Best Practices for Backing Up your SAS Content
Best Practices for Restoring your SAS Content
It is important that the system backup or third party backup you are using includes SAS.
Some background why this is so important:
The Metadata Server that stores all your metadata (users, groups, libraries, tables, web content,
folders etc.) is an in-memory server. When users request metadata, a copy of the physical table
is created and "put" into memory. It remains memory until the metadata server is paused and
resumed, or stopped and restarted. The pausing and or stopping flushes the content that
is held in mem, to disk. This is key!!
If you only run a sys backup without considering SAS, all data on disk is backed up,
however, what is kept in memory will not be part of the backup.
Think of it as a puzzle: you have a complete puzzle, and then you take some puzzle
pieces out and throw them away. You will never be able to put the puzzle back togther.
Same concept with the metadata server.
If you backup without considering SAS, whatever is kept in memory will not be part of the
backup. If a restore would become necessary, it would be incomplete, and with that, not
usable. Data would be lost.
The SAS backup facility (the different options are described in the doc mentioned above) runs an
automatic backup each night at 1pm. The SAS backup pauses the metadata server automatically,
runs the backup, and then resumes the metadata server. The pause flushes the content that
is kept mem to disk.
If you are running jobs at night, or, if you do run a backup during the day and users run jobs,
already submitted jobs are put on hold until the backup ran, then continue.
New jobs that are submitted are being "refused" until the backup finishes.
A SAS backup usually doesnt run very long. Of course this depends on the amount/size of your
metadata, but generally, it would not effect any work too much.
To use another analogy to explain users running jobs during a backup, the process of jobs being put
on hold or being "refused" during a SAS backup is like a phone call.
If you talk to someone and then put the person on hold, (s)he is still on, yet paused.
If a third person now tries to call you, its busy, and the call cannot be accepted. However, ones you
end the phone call, you can then be reached again. Same concept.
To summarize the above:
It is of the utmost important to have a proper SAS backup in place to make sure you can restore
successfully if it would ever become necessary.
Having seen many cases where data was lost, I cannot stress this enough.
Whenever you install a hot fix, a maintenance release, and whenever you make any changes to
your environment (significant changes), you can run an adhoc backup. Please take a look
at SAS Backup Facility
Hope this helps.
Please let me know if you have any questions.
Best,
Anja
