On Wed, Aug 10, 2016 at 04:11:53PM -0400, Alvin Starr via talk wrote:
Verify phase. You make me laugh. HAHAHA.
It's hard to do afterwards, since the data on the disk could have changed after you copied it unless of course you have enough space to stage the entire backup before writing it to tape. Good tape drive designs verify while writing (like LTO and such).
I did not write the code if I did then there would likely have been a verify phase. Some people kind of expect when you tell the drive to write the data its just written and if it were not there would be an error. Kind of like disk drives most times.
Anyway. When you do the verify you need to actually verify the data and not just the block checksums. Once upon a time a company I worked for had a bug that would write blank tapes. More correctly tapes full of zero filled blocks. They checksumed correctly so the quick check would succeed but not restore.
That's inconvinient. -- Len Sorensen