What kind of backup device to use?

[AstroGuardian]

I need advantages and disadvantages for both types of backup devices.
I could also use some links to web sites where some reviews are written about choosing tape or disk drives for backup and archiving.

Thanks,

 

[ForumMaster]

i'll admit i'm no expert. regardless, it all depends on the amount of data. if you're backing up TB's of data and you need the ability to constantly go back, then tape might be better. it is however, expensive. if you're a regular consumer, then an hdd should fit the bill best. i have this backup software that everyday, backs up any file that has changed from one backup.

 

[MerlinRML]

Tape Pros:
Higher initial outlay for the tape drive, but expect to recoup cost over time as each individual tape should be cheaper than a brand new hard drive
Scalability can be huge, as you can simply add more tapes or replace tapes
Portability is much better than mechanical hard drives
Speeds are actually pretty decent on the newer technologies, as fast as a single hard drive

Cons:
High cost of entry for any decent capacity, and smaller users will never recoup their cost because they won't use enough tapes
Can break during shipment, or during use
While throughput is pretty good, spin/wind times are very very slow
Large tape libraries are rediculously expensive, require constant maintenance, and break all the time
A single tape drive has to have the tapes replaced manually, or the backup job stops and doesn't finish, and moving to a tape library means much higher cost
Recovery takes a long long time, and if you have data on a really old tape format finding the proper drive and getting the software running may be a challenge


Disk Pros:
A single disk is cheaper than a single tape drive and tape.
Relatively speedy and increasing in capacity much faster than tape
Disks come with warranties, so if a disk starts to fail you can simply send it in, and if it's in a RAID array you can even rebuild the data
Disk arrays usually don't fail very often, and they handle single disk failures quite nicely as compared to tape libraries

Disk Cons:
Very expensive if you need lots and lots of capacity and the really big disk arrays do not scale infinitely like you can with removable tapes
Portability is very limited (by comparison), disks don't handle being moved well
Rebuilding from disks can be extremely complicated if you have different RAID controllers than you had or the disks are in a different position, or not all the disks come back to life.
Recovering from disks is fast, as long as the disks spin up and the software is available, and the interfaces haven't changed much


My own opinion is that a system of backing up your data that involves both disk and tape is probably the best solution. Add in data replication to the mix, and you have a recipe for amazing disaster recovery and restoration of service.