Hi,
LAN backups are always slower than locally attached. And 2TB of data probably means millions of files. So although your LTO3 drive is capable of backing up data much faster, it's got to get up to speed for a file, and stop, and repeat itself. This "seeking" on the drive can cause slow-down.
You mentioned you bought a 1GB switch. There is a bit of tweaking you can do there...change the port speeds on the switch to the maximum throughput of the connected server's NIC, and do the same on the server. In other words, 1GB FULL if possible. Hard-coding is preferred to autonegotiate.
You can also look at tweaking the settings of your tape drive within BE. You can push the buffers up, and see what performance impact this gives you. Please do test restores to make sure your data is recoverable and accessible before sticking to any changed settings.
For the rest...
1. Getting another drive does make sense, and budget allowed, go for it. It means you can split your backups up. I have done this on the Head Office site of 1 of our client, and it does help.
2. There is a dedupe calculator somewhere on the web. Deduplication will allow for smaller backups, but you need an x64-bit server to do this. This can potentially mean your initial backup is quite big, and subsequent backups are faster and smaller.
3. Look at changing your backup strategy. If you're using Full, look at Incremental/Differential. The downside to these are the number of tapes required for a restore.
4. If you go the B2D route, do not get a USB drive. It would then be better to simply continue backing up to the library instead. USB drives are dog-slow. A cheap NAS (Iomega StorCenter for example) can make use of your current LAN settings, and it runs at 1GB. From there, stream off to tape at leisure.
4. Look at seeing if your library can take LTO4 drives. This MIGHT lead to faster backup times, but if you can trial a drive, it will give you a better idea of things.
Hope this helps?
Laters!
