Backup should be a key component of any computer user’s routine.  No matter what we do with our computer, there are files you don’t want to lose.  The only way to guarantee they’ll always be there is to back them up.

For the day to day user or individual who is concerned with system failure or file loss the best method is RAID 1.  This process takes two hard drives and mirrors the contents from one to the other. After the initial setup there is nothing required from the user to keep this going.  The initial expense is around $100 for an IDE RAID PCI card, plus the cost of two hard drives, say Maxtor 20 GB drives retailing for $200 each. Total complete backup solution cost is $300 on top of the existing PC costs.  For a look at such solutions see my previous RAID article.

For the network user RAID by itself is not the optimal backup solution.  I still recommend RAID 1 or 5 solutions for the network file server, but augmenting this would be a tape backup system.  Tape allows for proper archiving of files that can’t be handled by RAID.  In my office a common scenario is this; someone comes to me and says the report they work on was screwed up yesterday, can I load the report from three days ago? Archival backup is the only way to handle this, as a site should be keeping between ten to thirty days of backups on hand for just such problems.

Tape is the preferred backup for archiving for one reason; it has the largest capacity.  Optical storage is good and fast, but maxes out around 5 GB.  There are quite a variety of tape technologies available: DAT DDS, DLT, Travan NS, AIT, Ultrium, SLR, plus brand specific types like Exabyte Mammoth, Onstream ADR and Ecrix VXA. Below is a chart that outlines the various technologies capacity, speed, and most importantly cost.  I’ve stated the total cost to be the drive plus 20 tapes, giving the user a full work month of backups.

by Scott VanderPloeg

A comment on the prices; it is noted that all costs listed are in Canadian dollars. This is a Canadian site, and proud of it. To determine cost in U.S. dollars, multiply the Canadian cost by 65% or calculate ( cost*0.65).

The big question to ask yourself is how large a tape drive to get.  If you have twenty staff members, each will probably have 100 – 200 MB of files on the server.  That equals 40 GB of data that needs to be backed up, so you’ll need a drive that holds that or more.  Of course this is an extreme example; most people on my network have less than 20 MB on their network share.  Again I recommend using the tape drive for backing up work files only; use RAID to back up the operating system and applications, which should be on a separate hard drive anyway.

 

Conclusion

November 15th, 2000