Safe Backup

[Scott7]

Hi, I've got a Pentium III, running OpenBSD 4.6 -Stable, its the firewall for my network at home, I also have a few programs running on it such as apache, vsftp and samba being the main ones.

I'd like to do a clone of the HDD every few weeks, but I'd like it to be automated, I can do this with a cronjob, my problem is as far as I'm aware, using DD to backup to another drive isn't all that safe when mounted? I'm hoping I'm wrong however I'd also like to if the main HDD does die, be able to swap the IDE cable over and boot straight off the second HDD I have in the computer and have backed up to.

My Question, is DD a safe way to backup when the HDD is mounted and the system is 'live' lets say? If not how would I go about doing the above in another way?

Thanks

Scott

[jggimi]

dd(1) just copies blocks. In whatever state they are in. Any data changing while your dd task is running will give you a low integrity backup. You will not be able to trust that you have a usable backup. Since you cannot ensure functional filesystems, another method for backup should be considered.

I recommend using dump(8) and restore(8), which are included with your OS. Missing data, such as log files that change, will still be missing, since you are backing up a live system.

If you have a database management system on that platform (PostgreSQL, MySQL, etc.) use the database's live backup facilities separately, since filesystem backup and restore will not ensure integrity of a database.

[Scott7]

Hi jggimi, Thank you for your reply. I also have a question about the new pf synax with OpenBSD 4.7, the reason that i've not upgraded my 4.6 install. I'll get this setup first though.

Scott

[jggimi]

Ask your question on a new subject in a brand new thread. It will make it easier for people who search.

But it is likely your question can be simply answered by the upgrade guide for 4.7, or failing that, in the PF Users Guide.