Link to home
Start Free TrialLog in
Avatar of jskfan
jskfanFlag for Cyprus

asked on

Backup Retention Purpose

If I understand  the purpose of Retention policy is to avoid having huge backup Catalog.

for instance, if you have differential on week days and Full backup on week ends ,Full the last week end of the Month, Full the last week end of the year, some do it the first week end of the following year if the week end does fall on December 31st.

to my understanding As long as your backups have run without missing any data, then regardless of the Retention Policy you have, your Backed up Data stays there and you can recover it.
I have seen some environments they configure Retention for 6 Months, Year, Infinity...etc..., I was wondering if the purpose of this Retention is to have smaller backup catalog ?
I also want to know, for instance if you want to look for a folder to restore from 5 yeas ago , would the Catalog expand and get bigger in order to have all the data from 5 years ago in order to find the folder we are looking for ?

any clarifications will be very much appreciated.

Thank you.
ASKER CERTIFIED SOLUTION
Avatar of rindi
rindi
Flag of Switzerland image

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Avatar of jskfan

ASKER

I was trying to understand how the catalog works in the case you are trying to restore data from 5 years ago, will the Catalog explore the media ? if the backup was considerably large ?
SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Avatar of jskfan

ASKER

Tapes are no longer used, at least in our environment.
when we need a restore we select from Netbackup the source (MS WIndows, NDMP, SQL.etc..) then the destination usually the same as the source. netbackup will explore the content of the storage (I guess that's the role of the catalog) to display what we can restore
So in our case the Catalog, I believe stays always large in size to know about every backup existing in the storage.
That would be nice, if the catalog stays small, and when you give the source and the destination , then at the time it should scan the storage , just like it does when you insert an old tape to restore from.
I don't know netbackup, but with many backup tools you can define how large the catalog should be, and you can also normally delete it yourself, or probably even disable it.

It's function is to be able to restore quickly. If there is no catalog or the backup media you want to restore from isn't included in the catalog, you first have to make an inventory of that media to find out what is on it, and that takes more time than if there is a catalog.
SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Also note that a backup is an object, it can reside on a tape, on a virtual tape, on a file, on a NDMP volume, it's really irrelevant for a backup sofware.

Where it physically resides it's part of the backup object's device properties.

The backup software opens up a backup media (file, tape, raw disk, VSS Snapshot, SAN Snapshot, NAS NDMP vol, Cloud Storage, etc) and it just pumps data into it, and keeps track of what it has sent there.

It doesn't matter if you use tape or not.

If you keep a small catalog and have to read each backup to restore a file, imagine a system with thousands of backups: it would take days to find where the file you want to restore resides (unless you do manual control of the backups).
Avatar of jskfan

ASKER

What I was trying to understand..

if you have backup on a tape, even if your catalog does not know about the data on the tape, it will still inventory it and will know about the data.

However if you have Huge storage of many Terrabytes of data on it and your catalog does not know all about the data on the storage, how is it going to inventory it and get to know about the data on it and then look for and find the data you want to restore.

I have seen environment that have the catalog backup retention set to Infinity.. that means it knows about every data on the storage except for the Expired data. However the Catalog size gets too large.

in this case archiving of the catalog makes sense...I am not sure how you configure Archiving in Netbackup
SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Avatar of jskfan

ASKER

Thank you Guys!