Only the first backup works

[eightcore]

Hi,

I configured the tool to backup the entire computer to an 4 TB USB drive. The job has been completed successfully the first time:
But since then, the backup fails at "Calculating digests" whenever I try it. Lets take a look at my storage:

• Volume C: RAID 0 with 2 SSDs
• Volume D: 2 older SSDs combined to 1 logical volume using Windows Storage Spaces
• Volume E: iSCSI LUN hosted on my Synology NAS, mounted via Windows Storage Spaces

In previous tests, I excluded volume E: in Endpoint Backup in order to minimize backup time. That worked perfectly. But as soon as I included volume E:, it's failing as described above.

Here's an example (the mentioned times match with those in the log files):

• I click on "Backup now"
• At 16:52:31 an "Application Error" is listed in Windows Event Viewer. Application: Veeam.EndPoint.Manager.exe, Module: VeeamEndpointSysUtils.dll
• At 16:52:46, the Veeam GUI reports that the "Processing finished with errors at [Date and Time]"

Here are the log files.


Can anyone help me?

[Gostev]

What is the support case ID for this issue please?

[Mike Resseler]

Eightcore,

Can you use the control panel, support tab to create a support case through the email option? After that, you will get a support case ID and you can post it here as Anton asked.

Thanks

Mike

[eightcore]

Thanks, I'll do that tonight.

[eightcore]

Hi,

the support case ID is 00883883.

[Dima P.]

Thanks! QA has already stared the investigation. Meanwhile, I am interested why you iSCSI volume mounted into Windows Storage Spaces instead of just mounting it as a regular volume?

[eightcore]

Hey Dima,

that's a good question. I think I was originally hoping that performance might be better due to Windows caching. Meanwhile, I highly doubt that, but I've never switched back to mounting it directly since I hadn't any issues.

Can I ask an off-topic question? How does CBT work in Endpoint Backup? Does it affect everyday storage performance?

[Dima P.]

Can I ask an off-topic question? How does CBT work in Endpoint Backup? Does it affect everyday storage performance?

Sure, we have Change block tracking – otherwise we would not have a forever-incremental backup mode. To tell the truth, it does not noticeably affect the performance unless you keep throttling backup activity option in the Control Panel > Settings

[Vitaliy S.]

How does CBT work in Endpoint Backup? Does it affect everyday storage performance?

It's both block level and modification date based, depending on the backup mode you use.

[eightcore]

Hi,

the issue is solved, they modified a dll file for me, and now it works . Thank you very much!

Sure, we have Change block tracking – otherwise we would not have a forever-incremental backup mode. To tell the truth, it does not noticeably affect the performance unless you keep throttling backup activity option in the Control Panel > Settings

I think you completely misunderstood me. I know that you have CBT. My question was how it works in a physical environment. In VBR for VMware, the VMware CBT feature is getting used and for Hyper-V, you've developed your own CBT filter driver which is running on the Hyper-V host. This driver writes the changed block data into a few files on the host.
But I haven't found any CBT implementation on my computer running Endpoint Backup, no driver (except "Virtual Disk Kernel Mode driver"), no UpperFilter or LowerFilter.

So I'm interested in understanding how it works in this scenario and if the CBT implementation does affect the storage performance (since it should continuously log every block modification even when no backup job is running).

It's both block level and modification date based, depending on the backup mode you use.

But Endpoint Backup doesn't let you choose between different backup modes...

[Vitaliy S.]

I was referring to entire OS image, volumes or file-level backups when talking about backup modes, so it's either block-level CBT of modification date one.

[eightcore]

I think I won't get an more precise answer.

Anyway thanks for your help! It works well now.

[Mike Resseler]

Eightcore,

I will try

When you configure your backup, you can choose between 3 modes: Entire computer, Volume or File-level backup.

Entire computer will do a VSS based backup and we use CBT magic to figure out what the changes are without the driver. That is necessary because on an endpoint, you never know what drivers and so on are installed . I can't go too much into details, but we investigate MBR for potential changes. (You have to admit, you got to love our DEVS, they really can do magic )

Volume-based backup uses above method.

File-level backup is different. It will look at the file modification date to determine if it needs to be backupped again.

That's why Vitaliy said there are differences in backup methods.

I said I was going to try so... Does this makes it a bit more clear for you?

Thanks

Mike

[eightcore]

Thanks for your answer! Yes, it clears up a bit.

So I assume that everyday performance is not affected at all since the CBT implementation is not continuously running in background, instead it's based on comparing existing metadata created by the system.
My assumption is backed by the fact that the backup size is usually clearly larger compared to the data which has actually changed (passive CBT does it's best).

Is that correct?

[Mike Resseler]

More or less correct

The assumption that CBT is not running continuously is indeed correct, but it is not really based on existing metadata. Again, we do magic

Cheers

Mike

[eightcore]

Okay, i've assumed this because you wrote this:

I can't go too much into details, but we investigate MBR for potential changes.

So, let the magic be magic. Thanks for your explanations!