Personally I would not use 1 month as a retention policy, it seems kind of pointless.
It may take a while to get the most retention because it is all about how many tapes you have.
To get the most "bang-for-the-buck" I have the most critical backups set for a longer retention than the less critical ones (my databases have a year and the servers themselves have 6 months). This is all based on the number of tapes I have.
My objective is to have them expire the week before I will need them again, that way I will always have a bunch of backups to fall back on. I have had users want a restore from as far back as 3 years, of course that is ridiculous but a few months should not be a problem.
As far as a full every Friday, again my critical stuff is full everyday and the lesser varies between full once a month and full once a quarter (PCs once a quarter, servers once a month)
The thing to not overlook is how hard will it be to recover critical data, the faster the better, especially when the VP is standing over your shoulder. After all isn't that the whole point of the backup?
Networker will keep writing to the tape until it is full, once it is full it will expire with the longest retention.
The tape is never overwritten until it is recycled, by this I mean that if you take a tape that has been written to and put it on a shelf for a year you can still recover the data using scanner command to read the tape and the recover command to recover it.
It never just deletes a single saveset on tape, it is an all or nothing situation
The tapes will expire when the one with the longest retention policy expires, it's a all or nothing kind of thing.
What you could do is create different pools so the ones with longer retention are on different tapes than the ones you need shorter retention, this way you can keep a good rotation going
The browse policy is how long you can browse for a file in Networker User
The Retention Policy is how long the backup is keep on tape, it can still be recovered even though it is past the browse time as long as it has not been overwritten using commands such as scanner.
The reason the are different is to save space on index files, at least that is the only reason I can think of.
So what I do is figure out the likeliness of someone needing a recover, usually they will know within a week or 2 so I set my browse policy for about a month. The indexes can get VERY large if you set the browse too long.
You have to separate automatic and manual operations/processes.
Expiration is an automatic process depending on your retention policies. For a tape it only changes the status depending on the save set status and the dependencies.
Labeling is either an automatic and/or a manual process depending on your Environment capabilities.
You can manually overwrite a tape at any time - you don't have to wait until it expired. You still rule the game!
That is where you create separate pools, so you can keep the stuff you want longer and let the rest expire. It will mean you have to have another tape for that
lalexis
2 Intern
•
253 Posts
0
August 5th, 2015 04:00
Personally I would not use 1 month as a retention policy, it seems kind of pointless.
It may take a while to get the most retention because it is all about how many tapes you have.
To get the most "bang-for-the-buck" I have the most critical backups set for a longer retention than the less critical ones (my databases have a year and the servers themselves have 6 months). This is all based on the number of tapes I have.
My objective is to have them expire the week before I will need them again, that way I will always have a bunch of backups to fall back on. I have had users want a restore from as far back as 3 years, of course that is ridiculous but a few months should not be a problem.
As far as a full every Friday, again my critical stuff is full everyday and the lesser varies between full once a month and full once a quarter (PCs once a quarter, servers once a month)
The thing to not overlook is how hard will it be to recover critical data, the faster the better, especially when the VP is standing over your shoulder. After all isn't that the whole point of the backup?
bingo.1
2.4K Posts
0
August 5th, 2015 04:00
"With the retention policy of 1 month, will the first week expires and deleted from the volume on the tape?"
- Will the first week expire?
Yes, about that. IMHO, you would do easier if you use the same unit (4 weeks, not 1 month).
Do not forget that all dependent save sets for the backup cycle (full-to-full) must become 'recyclable'.
NW will only set a full backup cycle to that status.
- Will these save sets be deleted from tape?
No - as tapes store save sets sequentially, you cannot delete a specific part (save sets).
You can only relabel a tape (aka 'recycling') and delete all its content.
Whether this can be done automatically, depends whether you have an autoloader but also on you NetWorker
configuration and of course your license model.
lalexis
2 Intern
•
253 Posts
0
August 5th, 2015 05:00
Yes and no,
Networker will keep writing to the tape until it is full, once it is full it will expire with the longest retention.
The tape is never overwritten until it is recycled, by this I mean that if you take a tape that has been written to and put it on a shelf for a year you can still recover the data using scanner command to read the tape and the recover command to recover it.
It never just deletes a single saveset on tape, it is an all or nothing situation
lalexis
2 Intern
•
253 Posts
0
August 5th, 2015 05:00
No, not quite
The backups themselves are what is stamped with the time and they expire as per the retention policy, doesn't matter what kind of backup is it
lalexis
2 Intern
•
253 Posts
0
August 5th, 2015 05:00
The tapes will expire when the one with the longest retention policy expires, it's a all or nothing kind of thing.
What you could do is create different pools so the ones with longer retention are on different tapes than the ones you need shorter retention, this way you can keep a good rotation going
lalexis
2 Intern
•
253 Posts
0
August 5th, 2015 05:00
Don't confuse browse policy with retention policy
The browse policy is how long you can browse for a file in Networker User
The Retention Policy is how long the backup is keep on tape, it can still be recovered even though it is past the browse time as long as it has not been overwritten using commands such as scanner.
The reason the are different is to save space on index files, at least that is the only reason I can think of.
So what I do is figure out the likeliness of someone needing a recover, usually they will know within a week or 2 so I set my browse policy for about a month. The indexes can get VERY large if you set the browse too long.
alexseb1
19 Posts
0
August 5th, 2015 05:00
Ok for i.e. if I set i month retention policy, nw will delete the save set of week1 from the tape. Right?
Meanwhile, nw will backup next weeks and in this way the tape will never expire. Right?
I want undestand when the tape automatically will delete all content backup
Regards
alexseb1
19 Posts
0
August 5th, 2015 05:00
I have 1 month as retention policy and my backup cycle is 1 week (1 full and 4 incremental).
I think that the tape never will be recyclable because one save set will depend Always from another.
Is it Correct?
Thanks
alexseb1
19 Posts
0
August 5th, 2015 05:00
Larry,
but if I want to use Always the same tape set (i.e. 3 tape), NW can overwrite the data on the volume tape?
Regards
alexseb1
19 Posts
0
August 5th, 2015 05:00
Thanks a lot for your support!!!
I'm agree about the tape number, I have about 10 LTO 5 in order to backup 2TB, so I can extend my retention policy.
My dubt is when the tape volume can be relabled and overwrite?
If I have the Full every friday and incremental every day?
If I understood, the all save set on the tape will not expires never.
Wrong?
Thanks a lot
Alessandro
.
bingo.1
2.4K Posts
0
August 5th, 2015 05:00
You have to separate automatic and manual operations/processes.
Expiration is an automatic process depending on your retention policies. For a tape it only changes the status depending on the save set status and the dependencies.
Labeling is either an automatic and/or a manual process depending on your Environment capabilities.
You can manually overwrite a tape at any time - you don't have to wait until it expired. You still rule the game!
lalexis
2 Intern
•
253 Posts
0
August 5th, 2015 06:00
That is where you create separate pools, so you can keep the stuff you want longer and let the rest expire. It will mean you have to have another tape for that
alexseb1
19 Posts
0
August 5th, 2015 06:00
OK!!!
I undestand that the browse and retention policy are useful for the index management.
The data remain physically on the tape
When the tape is full I need to empty it, but in this way I will delete my backup.
I don't want to delete all automatically because I have all my work on the backup tape.
alexseb1
19 Posts
0
August 5th, 2015 06:00
Ok, suppose that I have 5 LTO 5 in the media pool and all client configured with this pool.
When all tape are full,what's happens?
What's the right metod or criteria to recycle the tape without lose all my backup?
thanks
bingo.1
2.4K Posts
1
August 5th, 2015 06:00
NW will only append data. Consequently, overwriting is a 2 step process:
1. Relabeling/Recycling
2. Appending data with a new backup.