[Info-vax] strange backup behavior

[David J Dachtera]

glen herrmannsfeldt wrote:
> 
> B Hobbs <bdhobbs18 at acm.org> wrote:
> 
> < I've noticed that the more data on our backup SDLT tape, the longer it
> < takes to add additional files to the same tape.  When a file of about
> < 35 blocks (BACKUP-STUFF.COM;67) is backed up at the beginning of the
> < tape, that backup takes less than a minute.  Backing up the same file
> < after about 45 gigabytes of other backup files takes over 30 minutes.
> 
> As I understand it, LTO knows where files (tape marks) are on the
> tape using a small EEPROM in the cartridge.  I don't know that SDLT
> does that, which would mean reading the tape until the end, then
> start writing.  I don't know so many details about SDLT, though.
> 
> -- glen

The OP may be looking for info relating to "fast skip".

D.J.D.