# End to end verification breaks backups

#1

After enabling end to end verification for this client I’m getting
<time> ERROR Hashes for "D:\urbackup\Client\Backup-time\Path\to\File.ext" differ. Verification failed.
for apparently every file backed up, it’s so dramatic I almost wonder if server and client are using different hash algorithms?
Or am I missing something? Is an internet CBT client if that makes any difference.

#2

There is a difference between 2.3.x and 2.2.x. Could you tell the versions involved?

#3

Server is 2.2.11 Client is 2.1.19-cbt

#4

Sorry the combination is 2.2.x and 2.1.x. 2.2.x uses crypto++ to hash, 2.1.x was using a implemenation that returned wrong values sometimes.

#5

I’ll try bumping the client to 2.2.11-cbt beta then, see if the problem goes away… when I get chance.

#6

Well that was an “interesting” experience, I have no idea if the updated client clears the issue or not, what it does do is introduce a much bigger problem

Upon update the machine blue screens and goes into a constant reboot loop with the stop error WDF_VIOLATION, getting the machine bootable again requires system restore, after which the old client is broken.

Now I’m going to have to hunt round to see if I can find the installer for the old version, currently that machine has no client software, since I can’t use the current version on it, hopefully I saved the old installer somewhere

#7

Sorry about that. Do you have crash consistency on or off?

#8

On on that machine, only place it is.

#9

Turning crash persistence off seems to have cured the reboot loop, as for verification, I’ll try enabling that again at a later date, after backups have caught up, lots going on here, can’t really concentrate on such things.