Data Retention Period/Expiration

[jbalogh]

We cycle through tapes on a 4 week cycle. Data retention is turned on. My question is when does veeam decide to turn it on for a tape and not allow any more writes to a tape until the retention period expires?

I have noticed that it doesn't seem to be time based or if the tape is full based.

[PetrM]

Hi Justin and Welcome to Veeam R&D Forums,

Data written on tape is retained according to the media pool settings. The only detail to keep in mind is that if you select "Do not create, always continue using current media set" as media set option, the retention period starts after the first tape in the media set becomes full.

Thanks!

[jbalogh]

Thank you very much, that helps but I think I need more clarification.

We have a Dell Library with say 12 tapes in it. We are set to "Do not Create" for media set. We have hourly backups that get written to the tapes. How can we tell which tape is the "first" tape that when it gets full others get data protected too? How does veeam determine which tapes to data protect when the "first" one gets full?

[PetrM]

Hi Justin,

I'm not sure that I've got your question right, nevertheless I'd try to answer. If you select "Do not create, always continue using current media set" and specify time interval for data protection in media pool settings, the retention period starts after the first tape in the media set is full. The second tape in the media set will have retention period which starts after this second tape becomes full, retention of the third tape starts after the third one becomes full etc. I'd suggest to review this page to get more information about media sets.

For example:
The retention period is 7 days. Tapes 01, 02, 03 become full on 01 April as you have hourly schedule. The retention period will be expired on 08 April for these tapes.
Tapes 04, 05 become full on 02 April and their retention period will expire on 09 April.

Thanks!

[jbalogh]

I think that is where my confusion lies. I have tapes that are not full but have started the retention period.

[PetrM]

How did you find out that these tapes have started the retention period?

Thanks!

[jbalogh]

There is a column that is titled "Expires In". It either has a date, says expired or not defined.

[PetrM]

Hi Justin,

My previous statements were not accurate, sorry for the confusion. I discussed your question with my colleagues and we've found an issue in our technical documentation, we'll correct it soon. If you select "Do not create, always continue using current media set" and specify time interval for data protection in media pool settings, the retention period starts after the last write operation to a tape is completed. That's why you see non-full tapes with the defined retention. Also, the retention period for a tape can be extended if new data is appended to already existing data.

For example:
The retention period is 7 days. Tapes 01, 02 become full on 01 April. The last write operation on tape 03 is done on 01 April as well but this tape is not full. The retention period for these tapes will be expired on 08 April. The next day tape 03 is used again and the retention for this tape will be shifted, therefore expiration date of retention is changed to 09 April.

Thanks!

[jbalogh]

This makes sense, I appreciate it. Now I guess my next question is what is considered the "last write operation". Is that something I can determine or some veeam calculates?

[PetrM]

No, you cannot set it or change. The time of the last write operation to a tape is set automatically and can be equal to the job completion time or to the point in time when a tape becomes full.

Thanks!