Is the backup file consistency still checked when writing to tape/copying backups off?

[mkretzer]

Currently we are thinking about purchasing our first SSD based repo with embedded deduplication. Since there is always a slightly higher risk of corruption with dedup storage the question came up:
Does Veeam still check the checksums of the backups it backs up to tape (normal Backup to tape job just reading VBKs, running immediately after synthetic full)? What about BCJ?

[david.domask]

Hi mkretzer,

All of Veeam's traffic will be CRC'd in-flight, and there are similar checks when writing that the data written is actually what it should have been and that there weren't issues with compression dedupe/rehydration, etc.

For Tape and for extra assurance, there is Tape Verification so you can test the tapes periodically to ensure that the tapes are readable.

I think this is pretty good coverage to ensure that your backups are assured

[mkretzer]

Nice. But will the CRC be checked when reading from disk (reading the vbk file) before its writing to tape?
I know CRC is done for the traffic but that might not catch pre-existing silent data corruption on the disk. Backup verification will catch this, but will backing up from disk to tape do as well?