Order tapes being used in tape pool

[Vodochnik]

Hello,

I have 11 tapes in loop to additionally write backups as a second job.
They are labeled 071-081.
Last tape was 081 and I was thinking Veeam takes "next" tape from the top, 071. But no, it took 072.

2 days ago I have moved all "not yet used" tapes to "free" to have clear experiment.
Both 071 and 072 are erased and marked as free.

How do I tell Veeam the order of tapes to use in pool?
How to tell Veeam to take tapes from the pool in consecutive manner?



Thanks!

[david.domask]

Hi @Vodochnik,

Sequential selection isn't really used here, and Veeam considers other items first, including but not limited to the tape media set rules and also the overall "use" of the tape:

Media Pool Media Set Configuration: https://helpcenter.veeam.com/docs/backu ... ml?ver=120

My guess is that you have "Do not create, always continue" for the media set creation; in this case, Veeam wanted to continue the previous media set, so it picked the previous tape.

Can you confirm that this is what you have set?

What is your overall tape-out goal? Can you explain the strategy you want to achieve a bit more? Likely it's just a simple configuration adjustment, but describe it a bit more.

[Vodochnik]

Hi @david.domask

indeed, it's "always continue" mediaset, do not protect, always overwrite:


As I understand, Veeam takes free tapes from pool and if there are no free tapes anymore, it overwrites oldest tape.
There were 2 free tapes, 071 and 072 and I was thinking Veeam enumerates free tapes and sort them according to label.
In version 8 Veeam sorted them, I never had "random order" and next tape was predictable


My tape-out goal is to have additional "other media" backup, not easy accessible for cryptolockers and with 11 tapes I have 120TB space, some more as on NAS.
The "second" retention is longer as for regular backups.
Regular backups to NAS are forward incremental with active fulls every Friday, all regular backups have a second job to copy created vbk/vib to tape (incremental).
There are also 2 NAS2Tape jobs, they copy (incremental) backups from NAS to tape not as secondary job but per schedule (backups are from another site).

Another 11 tapes in the library are for monthly off-site full backups.

Regards,
Vod

[david.domask]

Hi @Vodochnik, thanks for showing, then that most likely is it.

Veeam with that option will try to use the most recent tape if it's available and has free space. Assuming the media set hasn't closed, this becomes part of the selection process.

For the tape-out goal, clear enough and it's pretty normal as I see it. What is the tape rotation strategy? You want a new tape for each day/week/month? A mixture? Should previous tapes be continued or we should start "fresh" each time?

[Vodochnik]

@david.domask

most recent is ok and it works fine, just if there is no more free space Veeam selects one of free tapes and the question is how to force selection of nr. 071 and not 072, in other words take first A and not B:)

There is no rotation strategy, 11 tapes are just like big HDD, every iteration of nas2tape jobs continue writing, if there is no free tape anymore, then overwrite oldest tape.
I think I have to present only one free tape to Veeam every time, hiding others in "free" pool and not let him choose.

But maybe some dev can look into code how next free tape is chosen if Veeam has a choice)
Technically it does not matter in which order tapes are used, it's just looks not really nice)

[david.domask]

Got it. The "Big HDD" approach is definitely quite convenient here.

Basically, easiest way for you to force it to the "next" tape is just force close the media set. On the bottom of this page, you'll see how to force it: https://helpcenter.veeam.com/docs/backu ... ml?ver=120

The order for selection is pretty straightforward:

0. Tape in drive has highest priority regardless of other factors. If multiple tapes in drive, continue on
1. Partially written tape if it's media set is not closed (if there are several, the one with more free space has higher priority).
2. Free tape from the current media pool (and current media set if it's a GFS media pool).
3. Expired tape from the current media pool.
4. Free tape from the Free media pool (if checkbox 'add tapes from Free pool' is checked).
5. If all other factors are equal, Total WriteCycles > then Alphanumeric
5a. As above, if TapeMediumSortByUsageStatistics is set to 0, we only consider Alphanumeric

So I think if you just rotate tapes out of the library, that is probably the easiest way to get what you want, and as best I know it's considered best practice to have tapes not currently being used taken out of the Library (usually for vaulting I know, but I suppose a secure box next to the tape Changer works too )

[Vodochnik]

@david.domask

Thanks man, this was the solution, I wrote a post with questions, but then googled for TapeMediumSortByUsageStatistics
Added this registry key, will observe if it works)
According to this topic it was broken in 11a, but should work now.

This behavior is since v10. Just add DWORD TapeMediumSortByUsageStatistics=0 under Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Veeam\Veeam Backup and Replication

Thanks again!

can you pleas explain this?:

5. If all other factors are equal, Total WriteCycles > then Alphanumeric
5a. As above, if TapeMediumSortByUsageStatistics is set to 0, we only consider Alphanumeric

If I have 2 tapes, first with 5 WriteCycles and second with 10 WriteCycles, which one will be preferred?
And how can I set TapeMediumSortByUsageStatistics to 0? Some "secret registry key"?

[david.domask]

Hi @Vodochnik, let's hope it settles it for you Else use the other items I mentioned, it will help.

For your (very small) question

Lowest cycles are chosen. To set it, just set it at that registry key path as DWORD.

[Vodochnik]

Unfortunately this registry key is not working anymore after upgrade to 12.1
TapeMediumSortByUsageStatistics

18.02.2024 18:22:02 :: Tape HAI079L8 is full
18.02.2024 18:24:30 :: Current tape is HAI071L8
19.02.2024 06:55:11 :: Tape HAI071L8 is full
19.02.2024 06:57:52 :: Current tape is HAI080L8

Is quite annoying, this behavior.
Any chance to get it working again?

[Dima P.]

Hello John,

Thank you for sharing the feedback! We will doublecheck this behavior!

[Dima P.]

Hello folks,

We've verified that the registry key works correctly. If confirm it's still misbehaving within your product installation on the latest build please raise a support case and share your case ID with us. Thank you!

[Vodochnik]

@Dima P.

Case #07241829