Introduction
If you are setting up Veeam CDP from scratch and are attempting to use seeding (seed copy) in order to speed up the process of getting the replication started, you may encounter the following errors:
- Failed to create long-term restore point
- VM configuration for the initial sync completed with errors
CDP seeding is when the backup files or replica of a VM is copied to a destination, and from there a CDP policy is created to replicate the VM from the original source to the destination and CDP will attempt to use the files that have already been copied to the destination to start the CD replication process rather than having to copy the entire virtual machine over the internet or LAN (depending on where you have CDP running). Seeding is typically used for transfers over lower bandwidth connections, such as the internet.
The Issue
Veeam support believes this issue may be caused by the UUID of the VMDK (virtual disk) from the seed and the original source being the same. When Veeam attempts to create the CDP replica checkpoint, a disk with the same UUID is already present and causes it to fail.
Possible Workaround
This issue has been seen with multiple builds of version 12. Veeam support has acknowledged this as a bug and has said they plan to have a fix for it in a future release, but have no indication of when or what release that may be.
Veeam suggested a possible workaround may be to change the UUID of the VMDK at the destination, however, in our own internal testing this did not work.
Retrieve the UUID
The UUID of the VMDK can be checked by using SSH to log into the ESXi host and typing the following command, where datastore, VM folder, and VM name are correct for your environment:
vmkfstools -J getuuid /vmfs/volumes/<datastore name>\<VM folder>\<VM name>.vmdk
UUID is 60 00 C2 9a 39 ef 7d 37-7c d6 b0 51 41 b8 b1 27
When running this on the original source VMDK and the destination VMDK, both UUID should be the same.
Change the UUID
To change the UUID, simply run the following command:
vmkfstools -J setuuid /vmfs/volumes/<datastore name>\<VM folder>\<VM name>.vmdk
UUID is 60 00 C2 96 99 01 13 61-76 3f 1c 9e 29 d3 e1 65
Conclusion
Veeam has acknowledged that this is a bug with CDP and seeding. While Veeam does plan to have a fix for this, the fix is planned for a future release, with no current indication of when or what release version that may be.
The UUID change may work for some cases, however, in our own internal testing it did not fix the issue.
CDP can still be setup by creating a new policy and allowing it to copy the data over the internet to setup its replica copy, and we have not seen any issues with this working.