Backup seem to ignore data

[karnalta]

Hello,

I am using Veeam Backup and Replication CE to backup my esxi host before rebuilding my raid array.

But I have a strange issue, I have a VM with several vmdk disks of 1 or 2 Tb. They all have about 400-600Gb of data.

But when Veeam backup them with the VM, it only take a few seconds and read about 4-5 Mb of data. So I am quite confident that my data aren't in that backup ...

07-02-20 07:36:03 :: VM size: 4,0 TB (1,6 TB used) <- Real size is probable 1.6Tb, so it's OK.
07-02-20 07:36:10 :: Storage initialized
07-02-20 07:36:44 :: Getting VM info from vSphere
07-02-20 07:36:45 :: Creating VM snapshot
07-02-20 07:36:55 :: Saving [P410-RAID-10] KN-AD-2019/KN-AD-2019.vmx
07-02-20 07:36:55 :: Saving [P410-RAID-10] KN-AD-2019/KN-AD-2019.vmxf
07-02-20 07:36:55 :: Saving [P410-RAID-10] KN-AD-2019/KN-AD-2019.nvram
07-02-20 07:36:56 :: Using backup proxy VMware Backup Proxy for disk Hard disk 1 [nbd]
07-02-20 07:36:56 :: Using backup proxy VMware Backup Proxy for disk Hard disk 2 [nbd]
07-02-20 07:36:58 :: Hard disk 1 (40,0 GB) 370,0 MB read at 34 MB/s [CBT] <- Windows Server 2019 (too small)
07-02-20 07:36:58 :: Hard disk 2 (1024,0 GB) 5,0 MB read at 5 MB/s [CBT] <- 430Gb of Data
07-02-20 07:37:16 :: Using backup proxy VMware Backup Proxy for disk Hard disk 3 [nbd]
07-02-20 07:37:16 :: Using backup proxy VMware Backup Proxy for disk Hard disk 4 [nbd]
07-02-20 07:37:16 :: Hard disk 3 (2,0 TB) 5,0 MB read at 5 MB/s [CBT] <- 630Gb of Data
07-02-20 07:37:16 :: Hard disk 4 (1024,0 GB) 4,0 MB read at 4 MB/s [CBT] <- 525Gb of Data
07-02-20 07:37:36 :: Removing VM snapshot
07-02-20 07:37:41 :: Finalizing

Even system disk is way too small.

I have no issue with others VM, just this one.

Anyone can help me ?

Thank you.

[Egor Yakovlev]

Hi Dimitri,
Is that a full or incremental backup? First job run is always Full(backing up entire disk), and by default subsequent runs will be Incremental(backing up only changes on those disks). So if your VM is shutdown or has very few changes, it is quite expected for backup to read only a couple of MBs and finish almost to instant.
Check backup properties under Home - Backups - Disk and you will see backup type for each session.
/Cheers!

[karnalta]

It was of course the first run, so supposed to be a full backup.

Others VM on this host has been fully saved.

[Egor Yakovlev]

Just to make sure:
1. Please, reset CBT on that machine, using VMware KB article.
2. Right click the backup job for that VM in Veeam console and select "Active Full". If you have multiple VMs in the job, just create another backup job specifically for that VM.
3. Report results here.
Thanks!

[karnalta]

Resetting the CBT seem to make it. Backup is now running and growing as expected (80Gb so far).

Does it mean that if you have your CBT faulted, even with a brand new backup job Veeam will be forced to make a kind of incremental backup ?

Because even with new backup job I had this problem on that VM.

[Egor Yakovlev]

Nah, new job always starts with Full backup no matter of CBT state and should backup entire VM no matter what.
If that happens again, maybe it will be worth investigating with Support via the ticket.
Glad it worked out after CBT reset!

[karnalta]

I will if it happen again.

Anyway, thank you very much for your support !