In my TS3100 tape library I have the FH LT04 Fibre Channel Tape Drive. Is it worth moving to the FH LT04 SAS Tape drive version? I see them less than $100 on ebay. Does the backplane board in the tape library needs to be changed out if I move a SAS Tape drive?
Your libray has 2 half-height slots for drives (the TS3200 / TL4000 has 4 half-height slots). You can use any full-height drive or 1 or 2 half-height drives. The drive's user data I/O interface is only on the back of the drive - the drive talks to the library over a dedicated loader interface, which is built into drive carrier frame of each removable drive. You didn't ask, but on the IBM drives the drive is the same for library or standalone use - it is configured by DIP switch on the bottom of the drive. That's why you see so many drive carriers without drives on eBay - the drives are worth more as standalone drives than library ones.
Your LTO4 drive uses a 4Gbps Fibre Channel interface. Moving to SAS within LTO4 probably just gets you a larger choice of host adapters on the server end and wouldn't affect the usable transfer rate one way or another.
Additionally, in the future I will probably buy a FH LT06 tape drive. So, the same question applies, should I purchase the Fibre channel or SAS version of the tape drive? Once again, my stock unit has a FH LT04 Fibre Channel Tape Drive.
LTO6 will read your existing LTO4 media but will not write to it. It will read and write LTO5 media (not that it matters to you).
Don't dismiss the HH drives. HH used to be a lot slower than FH due to the pancake tape motors - that's why you'll see something like "LTO4-120" instead of just LTO4. Generally, LTO4 FH drives are 120MB/sec and HH are 80MB/sec. On LTO5, both are 140MB/sec and on LTO6, 160MB/sec.
The biggest hurdle you're run into with switching to HH is the blank filler plate for the other unused drive bay. I can probably scrounge one up here if you need it.
On any used drive you buy, you should run the IBM Tape Diagnostic Tool (ITDT). It comes in Windows, Linux, and other flavors and you can get the latest version from the Lenovo site. Somebody probably makes a Linux live CD that has ITDT integrated. That tool will tell you the total power-on hours and number of power-on cycles, and you can then run some transfer tests to make sure the drive is working properly.
You will also need to bar-code your tapes with compatible bar-code labels. I have equipment to print custom labels, but unfortunately it is in storage at the moment. Click
here for an example.
If you don't barcode your tapes, the library will still work, but power-on and inventory commands will take a lot longer. Each slot in your magazines has a barcode sticker inside that tells the scanner "no tape" when there is no tape in the slot. But if the scanner doesn't get anything back, it will dance around back and forth and up and down, repeatedly trying to scan the tape barcode. If that fails to find a code, it extends a little metal finger and pokes the slots to see if there is a tape in them or not. This takes a lot longer than just scanning the barcode in one shot.