If you are putting a budget together to 'solve' - or at least make your backups more tolerable, I would probably start by making a list of everything that I needed the solution to do and work from there.
The key questions would be:
- How long are you planning to retain the data?
- is there an offsite requirement for your backup (whether professional or a kitchen drawer at home)?
- How much are your data growing (not point is sketching an 800GB plan that's outdated before you get it implemented)?
- is your existing backup software capable of dealing with your requirements?
- is your existing hardware capable of dealing with your requirements?
If you are aiming for a weekend full with daily incremental jobs, you are looking at storing around 4TB a month (depending on your required retention), so unless you woke up and found a nice storage array at the end of your bed, it looks like you'll be stuck with tape - which isn't too bad!
Looking at your existing backup solution, you are backing up 300gb in 20 hours (!!) that is an extremely low number and I would guess that the reason for this can be found either on your network or on the server doing the backups (AKA the media agent) - the drive alone should be well capable of delivering at least 5-6 times that speed - even over the network you should be able to push around 1GB/min through to the drive (depending on network type and traffic ofc.)
If I were in your shoes, I would probably look at replacing your existing LTO drive with something a little more beefy - LTO4 has a native capacity of 800GB, and with a little compression, it should be able to keep all your data on a single piece of media (nothing like coming into the office Monday morning to see the weekend job at 42% and a mount request plastered up on the screen). LTO3 should still be able to get the job done – it is most likely half the price of LTO4 and would be able to write to your existing LTO2 media (still only 200/400) but could help in the transition to a newer technology (LTO4 is still read capable of LTO2 media).
Next, I would look at how the data is getting to the drive - the absolute cheapest way to get the drive fully utilized would be to have a dedicated network for your backups. If you can keep the data flowing to the drive, this might not be needed, but if you have a lot of traffic at night, this might be a solution. Also, have a look at the media agent - even if it serves as a file and print server, it should still be fully capable of keeping an LTO drive busy during the night - unless it has another role on your network that interferes with your backups.
Veritas Backup Exec is fine for what you need, so no reason to start spending time/money learning something else. You might need a couple of additional licenses for the added servers, but other than that you should be fine.
I would always try and aim for daily full jobs - when possible. If you are capable of getting the correct infrastructure in place, you should be able to get your 800GB jobs done, well before people are showing up in the morning, so if at all possible - aim for full jobs. If you are getting close to bursting the window, start looking at how you can improve the time to complete. It might be worth running an incremental on some servers and prioritize full jobs on others.
Also make sure that you are using the proper agents e.g. SQL/Exchange - A good backup solution is like life-insurance - if you try and stitch something together you might end up taking a hit when needed the most, and really sad to see a company go bust simply because it failed to plan for the worst.
From a backup administrator perspective, if your proposed plan isn't honoured by management, make sure you protest openly (and keep the rejection mails - in hardcopy) - you'll need it when the management team pays you a visit after a server loss, as you'll swiftly be promoted to numero uno on the blame list!
