Which Backup method is best for us?

[Hassan_Ali]

Presently we have Veritas Backup Exec doing a full backup - reset archive bit on a daily basis. this has worked fine but I have been told this is not good for the hardware (tape drive).

the backup every night is roughly 70gig.

Can someone tell me then which is the correct method? i.e. incremental or differential. I have checked and found that there are 10 different types of backups on the Exec 9.1 software.

Presently this is how we backup are tapes
One each day - Mon, Tues, Wed and Thurs ? these tapes are used again the following weeks on the same days.
Friday Tape 1, Friday Tape 2, Friday Tape 3 - these tapes are used again every 1st Friday, 2nd Friday, 3rd Friday.
Friday Tape 4 - these are used once only and then kept for 12 months.

I would be more than grateful if someone can tell me how and why rather than redirect me to another link.

Regards

Has

[A_van_der_Boom]

I think it all depends on your recovery plan. How much time you want to spend to reinstall crashed servers etc. and how much data you have that needs to be backupped. I don't believe reseting the archive bit is bad for your tape hardware, this is done on your servers harddisk not the tapedrive itself. You can reset that bit as much as you want.

If you make full backups every night you can restore all data in one go. If you use full backups in combination with differential or incremental. You need to restore first the full back and affterwards the differential/incremental tapes. So this will take more time to restore then only full backups.

On the otherhand if the amount of data is that much that you cannot backup it within the required timewindow you will probeably not be able to perform a full backup every night. You will have to find another way to backup safely all your data.

You can try searching the BE site for some documents about backup/restore strategies or try Google. Maybe someone else here has some other pointers about how to backup/restore safely.

Regards
A van der Boom

[Hassan_Ali]

IThank you very much for your answer. I do not want to spend too long reinstalling a crash server - but I don't want my hardware (external) backup tape drive to wear itself out. I am not sure what reset archive bit does?

At present it is already doing full 70 gig backups every night, is this good for the tape drive?

the present time window take about 4-5hours to back up all the data, which is fine at the moment.


I will see if I can find anything useful to read about what is the best way to backup but all the posts i see on the web, they all use a different method.

I just need some guidance what is the best method with the information I have provided.

[Stuart_Feldman]

We curently do a full nightly backup. About 75GB compressed. We'd rather do it that way and make any recovery that much more simple, easier, and faster than be concerned with the life of the drive. Ours also takes around 4-5 hours. Our drive is speced for an mtbf of 250000@100%. Seems like a long time if I'm calculating it properly.

[Joshua_Small]

If you are able to fit a full backup onto a single tape, then you should do a full backup every night.

Anyone stressed about the impact of this on your tape drive is too concerned about doing things cheap to be interested in doing good backups.

Sure, there are other types of backups which are good in situations. Those situations usually involve a backup that won't fit on one tape.

[Gauri_Ketkar]

Hi,

Refer Admin Guide for further info on backup methods :

VERITAS Backup Exec (tm) 9.1 for Windows Servers Administrator's Guide (English)

http://seer.support.veritas.com/docs/266190.htm
Page number 355 onwards


Update us on the same and revert for any further Query
Hope this will help you


Thank you
Gauri


NOTE : If we do not receive your reply within two business days, this post would be marked "assumed answered" and would be moved to "answered questions" pool.

[Hassan_Ali]

Thank you guys for all your help.

I think I was more worried about the stress to the backup tape drive rather than the implications of a recovery from a disaster... and the easiest option is to do a full backup every night that's if my tape size will allow it and it does. This is what Joshua and A Van Der Boom have explained. So many thanks for your help once again... until next time... when the size of the tape is too small and I will have to look for other options. No one did explain 'Reset Archive Bit'?

Regards

Hassan

[Joshua_Small]

Conisider this.
If all you do are small differential backups, sure, you will be spending less time actually writing to a tape.

However, the start of your tapes will still be overwritten every backup, and when the start of your tapes wears out, the tape will fail regardless.

If it's the tape drive you're more concerned about, don't be. Your tape drive should last long enough to be due for upgrade before dying, no matter how much you use it.

[Ken_Putnam]

There is a bit in the MFT for each file. When you make a change to the file, this bit is turned on.

A full backup will turn the bit back off.

An incremental backup will backup only files that have the bit set on, and will turn the bit off, so you only backup files that have been changed since they were last backed up.

A differential backup will backup all files that have the bit set, but will NOT turn it off. This means that you backup alll files changed since the last Full backup.

For Incremental backups, you must restore the last full and all subsequent backups, in the order they were taken. For Diffs, you restore the last Full and the last DIFF

OF course if you use only Full backups, you restore only the last FULL

[Hassan_Ali]

You guys are making sense.

Thanks Joshua and Ken - very simply explained in the best possible terms.

As suggested full backup every night... until the tape drive decides to die one day?

But at the moment backup takes between 5-6 hours and is set up for a nightly backup which does not affect anything..except recently to the POP3/SMTP which I am still investigating - could this be because its backing up exchange it stops and starts the services causing it to go down during the backup hours?

Ken when you say MFT what do you mean .. remember I am still a novice with Server / Veritas etc. but I have understood the rest of your methods about backup.

I have enough space on the tapes another 10gig of free space.

But I recently get the following messagein Alerts:

Media Overwrite Protection is configured to overwrite allocated media.

Please consult the online help for more information on allocated media.

and

Don't forget to run the Intelligent Disaster Recovery Prep wizard to update your disaster recovery disks.

Can you let me know your thoughts on this as well as the email issue during the night where it will not send emails.

Many Thanks

Hassan

[Joshua_Small]

Hi Hassan,

Veritas won't stop any services by default.

Do you have mailbox backups in your backup selection (as opposed to "Information Store")?

Mailbox backups, aside from being a kludge, shouldn't be needed, and are much slower than any other backup.

[Hassan_Ali]

The following is backed up overnight

- Microsoft Exchange Mailboxes
- Microsoft Exchange Public Folder
- Microsoft Information Store

as well as the the other stuff on the Hard Disks. (we have a all in one 'Microsoft 2003 SBS') which has all the files and folders of the staff, exchange and SQL.

I do get a lot of event warning or errors in Event Viewer during the night when it does do the backup.

What's the reason behind this?

Are you saying to remove one of the above items, of mail??

[Ken_Putnam]

I meant MTF - Microsoft Tape Format.


The format that BackupExec uses to write data to the tape. AFAIK, all windows based backup systems will at least read MTF, and I beleive that they all use it to wite the data

What specific Event Log entries are you getting during the backups? Any alerts on the console? anything of note in the job logs?


As far as your selections. I's seriously look at why you are backing up individual mailboxes. They are totally useless for disaster recovery (but you are doing stores backups, so you are covered there), they are extremely slow compared to stores backups, when you go to restore them, you may have all kinds of problems (scan through the forums), and roperly managed, your Exchange system shouldn't require them. except for a few very high profile users perhaps.

It is a little dated by now, but take a look at http://mail.tekscan.com/nomailboxes.htm . It is a pretty good argument for NOT taking brick level backups


If you the backup window available, I'd stick with Fulls every night. Just be sure that the every second or third year you consider new hardware in your budget for the year. Remember that the new drive should be atleast read compatible with the old drive or your current tapes will be useless. (unless of course you keep the old drive on a shelf, waiting to be used :) )

Message was edited by:
Ken PutnamMessage was edited by:
Ken Putnam