Reasonable backup rate but slow restore rate

[Michael_Strelit]

Running Windows SBS 2003 and a half height LTO2 using BE 10.1d, I get the following results - regularly:

1. Backup 209GB (mostly winzip compressed data) in 2Hrs 18min - 1451MB/min (Ultrium 2 cartridge).

2. Restore 22.6GB of the data in 1. in 2hrs 40min - 135MB/min This data is from 8 folders including both the first and the last ones backed up.

Is this correct? What can I do to improve the restore rate?

[Ken_Putnam]

In my experience, restores run at about 10-15% of backup rates, so you are right in the ball park

I've never had anyone give me a reason for the difference, but it seems to hold across multiple versions and tape drives (for me at least) I assume that it has something to do with having to create the MFT entry before actually writing the data to disk, and the associated overhead of random access writes, while the backup is straight sequential writes, but that is strictly conjecture on my part

[Michael_Strelit]

Thanks, that was helpful, but there must be more. Restoring a multi-GByte file gives about twice the speed. I would still expect more. Once the data is streaming in there is no difference between restoring from tape and copying/moving the file and I can certainly copy a large file at above 1GB/min.