[bareos-users] Tape concepts

[Tam Angustia]

Hi All,

I am curious as to the nature of how a tape drive works. I have a bareos 16.2 setup with a dell tl-2000 tape library interfaced to a supermicro server. I have done a somewhat extensive testing of the tape and a few test backups as well and it worked fine. I did this a couple of months ago and forgot to document a restore test with the tape drives. The setup for the pool on bareos has been configured to use the nts0 drive meaning it wont rewind. But for testing I just manually rewinded the tape and issues weof to somewhat rewind the tape but here's the questions. If anyone has an idea or is adept with tape drives I would like to ask a few questions if you dont mind.

P.S The tape is re-writable. Using centos 7

1. How does one know if the tape drive is full?
2. Does doing a rewind and weof erases the data on the tape? If not then if I reused that tape with the issued commands will it erase the data then write the new data on the tape without any issues or errors?

thanks is advance, Though I will be testing a restore sometime next week, nevertheless I would like to here anyone's opinion on the concept of tapes

[diamaunt]

Post by Tam Angustia
1. How does one know if the tape drive is full?

The tape sends back an EOT flag that tells the software it's full.

Bareos keeps track of how much data is on the tape, but if you've got compression on, "full" can vary.

Post by Tam Angustia
2. Does doing a rewind and weof erases the data on the tape?

Well, no, it doesn't erase the tape. What it does is to back to the start of the tape, and say "The end of the data is here."

Tape is a linear thing, it starts at one end and goes to the other (well, technically it zigzags, but each zig and zag just puts you further from the logical 'beginning'. It's an always append thing, till you fill it up.