KiltedKnight's Journal: Yep... it had to be something stupidly simple

It's not like I wasn't expecting it... but when you move a SCSI AIT-2 tape drive from an older machine to a dual-core Xeon with a RAID, you expect equivalent performance.

Wrong.

Backups that were completing within a day were now taking 4 days.

The solution? the --block-size=n option to cpio, where the block size is n * 512 bytes.

By setting it to be the transfer rate (found via cat /proc/scsi/aic7xx/1 on this machine), it completed in about 2 hours.

You would think someone would've built the smarts into commands like cpio, tar, and dd to do some kind of calculation on best performance instead of using some tiny number that works if you're only looking to back up a single, small file.