CBT stopped working in v6: Incrementals full read

[tminkov]

One question related with CBT and new version of agent v6. If needed please move it to new post.

Last two years I used Windows Backup agent v5 for OS (NTFS) and plenty of Files located on ReFS. CBT worked fine, incrementals are incrementals.
Upgraded to v6 and CBT stopped working, incrementals are fulls. I see in v6 release notes that CBT mechanism was changed.
What is your opinion? What i should do: reverse to v5 or wait for v6 bug fix?

[Mildur]

Hello Tminkov

Is there any error message in the job session details?

What is your opinion? What i should do: reverse to v5 or wait for v6 bug fix?

We cannot fix something we don't know about. Please create a case with customer support and upload the logs. If it's a bug, a private fix will be provided.
Please don't forget to post your case number.

Best,
Fabian

[tminkov]

Hello Fabian,

No, there is no any error message. Except "Backup location [.....] is getting low on free disk space."
I dont expect for forum to fix the issue, thats why i asked for opinion, if someone hit the same case.

It is a free edition so I will try to rise a support case. If not, will try v5 again or something else.
Thank you very much!

Regards,
T. Minkov

[eider]

In case it helps you, I have observed increased size of incremental backups only on first run since upgrade from v5 to v6 (case #05888070) however all subsequent runs are fine and there are no visible adverse effects on backups going forward. Support did confirm this behavior and will most likely look into root cause internally later.

Did you observe this behavior only on first run since upgrade too?

[chris.childerhose]

Since upgrading to the v6 agent, things are running as expected for me with Win11 and incrementals are small depending on what I am doing on my laptop. I would suggest a Support case to get to the bottom of the issue.

[tminkov]

Thanks for the replies!
Actually the topic should include "ReFS as Source", because that was/is culprit.
In v5 I (remembered later) installed "CBT driver" found in CBTDriver folder.
After Veeam upgrade CBT upgraded to version 12 but the incremental was full size. I dont have target size for 2 fulls so my first/next incremental ends with error.
Nevertheless deleting the target and starting from zero didnt helped, again first incremental was full size and ended with error.
Then I deinstalled and deleted all Veem folders and installed fresh new v6 and tested:
- Veeam v6 w/o CBT driver - CBT not used on ReFS Sources, this is fully expected
- install of CBT driver - after Windows 2022 restart ended with BSOD "Inaccessible boot device"
Meanwhile on same computer I added a disk and installed a fresh new Windows 2022 (same version as old one but old one was upgraded from 2019 upgraded from 2016)
Till now I have no option to test CBT driver instalation, maybe will try with next Veeam v6.
Using Veeam v6 with NTFS sources, and simple copy/paste with ReFS sources (pics/videos with no compression/deduplication).

Regards,
T. Minkov

[Mildur]

Hello Tminkov

Our CBT driver is not available in the free Agent version. Don't install it just from the "folder".

Best,
Fabian

[tminkov]

https://helpcenter.veeam.com/docs/agent ... tml?ver=60
[Install CBT driver] is not visible, maybe because Free version.
So how I succeeded on old Windows...

If I cant install CBT driver 12 then my choises are:
- end with Veeam and found another solution with ReFS Source support
- go back to v5

Thank you very much for this topic!