Advantages of tape backup vs other media?

[Red Squirrel]

I've been wondering, being tapes and tape drives are very expensive, and not as easy to use as non sequential storage, why is it that they are the most used in backups? With the price of hard drives going down, I can see having a bunch of hot swap enclosures be more cost effective. Say you have 8 bays that gives you 8TB of backup without needing to swap anything out. (no raid, just individual drives). Each drive could have a label or something so it runs the proper job and you just have to be sure to swap them every day.

The backups would probably be faster too, some would probably take less then 1 hour if hardly anything changed.

The only advantage of tapes I can really think of is that they might be more reliable when stored. Any other advantages I'm missing? I'm guessing they must be industry standard for a reason, over removable hard drive based systems.

 

[RebateMonger]

Here are some pros/cons for tapes:

1) With the use of magazines, they can have a very high total capacity. Since the largest hard drives are 2 TB, to get total capacities larger than that with hard drives, you have to either create arrays or come up with a way to make backups to multiple hard drives.

2) The high-end tape drives can be very fast.

3) The tape media can be cheaper than disks of equal capacity. But not by nearly as much nowadays as a few years ago. Tapes tend to make keeping archival copies of backups a bit cheaper and easier

4) The tapes are mechanically more durable than hard drives. You can drop them and they'll still work.

5) On the other side of the scale, is the mechanical vulnerability of the tape DRIVES. In the small businesses that I serve, I seldom run across a WORKING tape drive. They break and nobody notices. But a site with a functional IT group would notice the failure and get the tape drive(s) fixed.

When a tape drive breaks or is stolen, backups and restores won't happen until a replacement drive is located. With hard drives, you go to Best Buy and buy a replacement drive. In the meantime, all your other backup drives remain fully usable and accessible.

6) And then there's the pricetag. High-end tape drives are very pricey. Large businesses can better handle the pricetag.

In general, you'll find hard drives doing the backups in small businesses and tapes doing the backups in large businesses. More and more, you also find hard drives used as an intermediate step to speed up initial backups and as a location for hourly shadow copies of changing files. Tapes are written from the intermediate hard drives, allowing tape backups to run 24/7 without slowing down the servers being backed up.

 

[skyking]

That has been my (limited) experience also. Tapes are OK, Tape drives can be a PITA.

 

[CrimsonWolf]

Easy shipment of backups to off-site locations seems like a plus for tape backups.

I'm not in IT, but I work in a small office for a larger company with remote IT support. They give me a call whenever they need someone to take a look inside the server room for anything.

My understanding is that they run an incremental backup to a tape every night. Then each week they run a complete backup. They email me the tape number, I eject it from the drive, put it in a locked container for Iron Mountain pick up, and then it's stored off-site. It's no more than 5 minutes of work on my end each week.