Native Drives, or from something like Veritas NetBackup?
In either case, for any specific variable within SunMC, there are two reporting packages I know of.
1) Sun's Performance Reporting Manager (PRM) installable during the SunMC setup
2) Halcyon's Reporter Product
http://www.halcyoninc.com/products/Reporter/index.php
Both these can be applied to the tape info in the Kernel Reader module, or to data supplied by something like Halcyon's NetBackup module:
http://www.halcyoninc.com/products/VeritasNB/index.php
iMac
That's correct, the Error I/O is shown in the kernel reader, and I don't beleive tapes are reflected in the Disk Stats.
The Halcyon Veritas NetBackup module has a Transfer Rate (kB/sec) for specific backup job performance. Thats the only transfer metric I know of related to tapes.
If you have a method to derive/obtain the value on the command line, using scripts/cron, you can pass that value up to SunMC using the PrimeAlert ScriptRunner product too.
cheers,
iMac.