Backup strategy? Differential / incremental not worth it?

I got into a debate with some other people about doing a full backup each night vs. full 1x a week, then incremental or differential.

on the pro side of full each night, restores are easier (but hopefully restores are infrequent / rare... but when you need to do it, you don't want to waste time grabbing different tapes), any 1 tape has all the data up to that date.
on the con side - backups take longer (but as long as it runs overnight / done by the morning, so what?), more wear and tear - backing up gigs of data each night vs. a couple / few meg that changed recently) - you'll have to replace the tape drive sooner than full / incremental

on the pro side of full / incremental - faster backups, less wear and tear on the tape drive / tapes.
con - restores take longer, have more tapes to have on hand to do a restore.

Please share your thoughts.  All participants will be awarded points.
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Full- as you mentioned takes the longest to run, but is the fastest to recover.
Diffential - Should have a full backup to differentiate from, backs up all from the last full backup, and a restore will omly take two restores to recover the data.
Incremental - Backs up only what has changed from the last incremental or full backup, backup will be the fastest, but to restore requires all the backups from the last restore to get the data to the latest version.

From a DR point of view a Full is always the best to go, why? Because it is the fastest and if one backup tape is faulty you only need to go back one tape to get you up and running. If a problem arises speed will be the critical but this will need to have been assessed at the start and on going. Can a business servive with their server down? Some businesses could go bankcrupt just by not having a working system for even less then a day.
In my opinion I would never deploy a server that was not running full backup, unless backup time was an issue. I would run a full backup at the weekend, and differentials twice a day, during lunch or low peak network and at night. If you had a problem with one tape you canreliably go back to a day before and know you had all the data till then.
Incremental should be avoided, imo, as you need to have all tapes valid since the last full backup to ensure you get all your data back, if one tape is invalid or corrupt you have lost a days worth of data, where by the other two you have a greater chance to recover data, where some tapes will have duplicate backups.

One other note, to clear the log files of exchange, a full backup using an exchange aware backup utility such as NTBackup or Veritas with Exchange plugins enabled to clear the logs.

Hope this helps,

Jeffrey Kane - TechSoEasyPrincipal ConsultantCommented:
Everything David said I fully agree with... The only thing I would add is that I don't use tapes anymore.  Instead I use USB Hard Drives which allow for a couple of things... they are faster and you don't have to switch anything to complete a full backup.

I generally try to keep full backups to no more than 30GB for a 20 person office.  This means having a good data management policy which includes a comprehensive archiving plan.  Data that is not accessed regularly should be archived in the same manner we used to do in the old days of having tons of file cabinets in the office.  At the end of each quarter, year, or whatever, the old files are put into storage and the current ones rotated down to make room for the new ones.  If an application is no longer being used on the server then it too should be removed and it's data archived.  All archiving is done to HIGH-QUALITY DVDs.  We make two copies, one to keep onsite and the other is removed off-site.

Which USB hard drives you use would depend on your budget.  If the backup is kept to under 30GB, then you can get by with a couple of 160GB to 250GB 3.5" drives which can be swapped daily by someone who keeps the other drive in their breifcase to take home at night.  These are rather heavy though compared to the 2.5" drives... but those currently only are available up to 160GB and cost about twice as much.  Ideally, though, I prefer to use THREE 120GB 2.5" drives that are rotated every day.  Having the third drive covers the possibility of someone not bringing in the one that was taken off-site the day before.  It also allows for a total of about two weeks of backups to be stored before they get overwritten.

Backing up 30GB onto an external drive should take no more than a couple of hours, so it's easily run in the middle of the night.  If the company has a lot of LARGE files such as photographs or CAD files, I'd suggest getting a separate storage server with Data Protection features, and perhaps a separate backup to USB drive which can be done on a much less often interval.

I'm also on the bandwagon that FULL backups are the only way to go, unless you absolutely have to use diff/incr for some reason.  As for the wear and tear on the tape drive, I think that is a really weak argument either way. I've got clients who have used the same drive for years running full backups, but then I've got other who have to replace their drive every 12-18 months. I really think the server environment is a much bigger factor than the usage time.

As for archiving to DVD, I used to really like that idea until I read an article about the shelf life of consumer DVDs. I can't find the link at the moment, but it basically said DVDs have a shelf life of 4-7 years, compared to DLT tapes at 20+ years. Take it with a grain of salt, but it is worth considering. If I can find the link I will post it here.

As for backing up to USB hard drives, I am becoming MORE a fan of that. Especially as prices come down and capacity goes up. I like the rotation scheme TechSoEasy outlined.
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TechsupportwhizAuthor Commented:
With SBS, what app are you using to do the full backups?  And when you say full, are you meaning the entire drive or just data?
Jeffrey Kane - TechSoEasyPrincipal ConsultantCommented:
SBS doesn't need an "app" for full backup... it has it builtin.  Run the configure backup wizard in the Server Management Console.

Full means FULL.  Including System State and Exchange DB's.  If you have any SQL Databases, I recommend creating a SQL Maintenance plan to back those up separately, but it can run right before or right after the other backup.  Usually I create a separate partition on the USB drives for these.  This is redundant because restoring from the FULL SBS Backup would work... I just think that generally if you have data in SQL server it's valuable stuff.

See for more info.

Jeffrey Kane - TechSoEasyPrincipal ConsultantCommented:
technologyworks... I saw that same article... which is why I stated HIGH QUALITY.  There are different qualities of both DVD's and DVD Burners... this certainly should be taken into consideration.  A hight quality DVD that is burnt on a decent burner should last hundreds of years, actually.

I know that a lot of consultants are moving to usb drives for backup purposes and have found them to be very successful. My own opinion is that I prefer not to use them as removeable storage but as a NAS, and my reasoning is just that it requires someone who will look after the drive, by dismounting it, and then not throwing it around and such, and sadly I do not trust them enough.

The long and the short of choosing the media that you will use for backing up to is what are your clients competant and capable of using, and to which are they most likely to find easy to use. If they are very forgetful and continue not to rotate backups then you may have to look into online or other automated processes to suit this type of client.
It is also a case of what you as the consultant are happy to deploy, do you know the technology? Do you believe it meets the high qualities that you have for your business and up to the standards your clients expect. Its all semantics.

David Houston
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