Doubt about Full Backup

[hispa]

Hi,

I am administering a Zimbra NE, i've seen that incremental backups are being done well, but with full backups i'm not sure since it's size it's very small.

I have 500 users right now, and in incrementals backups there are days where i get 6G - 11G size average, but in full backups i get sizes like 211M or something like that. How is this possible that incremental gets longer than full backups?

Here is the output from zmschedulebackup -q

Default schedule set

Current Schedule:

f 0 1 * * 6 -a all
i 0 1 * * 0-5
d 1m 0 0 * * *


Another thing, what files are being backed up?

Thanks in advance.

[iway]

Well, full backups of all accounts are run only once a week. All other days, the full backup only holds the newly added accounts since the last full full backup.
Can be a little confusing...

[dustys]

If I'm recalling this right, incremental backups will contain any new accounts plus the redo logs since the last backup. The traditional full backups that are performed by default use hard links on the file system to reference previously stored blobs in the current backup, rather than storing them more than once.

This may be of help also: Network Edition Backup Procedure

Cheers,
Dusty

[hispa]

full backups are done once a week, and the others day it only makes incremental backups that are the differences between the last backup until the moment it begins to backup.

Full backups are a set of incremental backups joined together.. how can it be than an incremental backup is larger in size than a full backup? i don't get it.

As its size, i don't know if i can trust in my "full backups" in case i have to use them to recover my system by a disaster situation.


Thanks.

[Rich Graves]

"Full backups are a set of incremental backups joined together"

For a traditional tape backup, this is generally true. For a deduplicating, single-instance disk-to-disk backup regime with database redo logs, it's not.

By all means, test your full backup restore procedure now; don't wait for an actual emergency. Shouldn't require downtime. NFS-export (or SAN-snapshot and clone, if possible) your /opt/zimbra/backup. Mount on another box. Follow the disaster recovery procedure from there.

[mertz]

Originally Posted by iway

Well, full backups of all accounts are run only once a week. All other days, the full backup only holds the newly added accounts since the last full full backup.
Can be a little confusing...

Hello,

Just to be sure (as I can hardly check this on a new unconnected zimbra server) could you confirm that :
- the small full backup created automatically during the week when a new user is added is OK (with its small size)
- and it will not prevent correct recovery assuming I have real weekly full big backup available (+ the incremental backup) ?

thanks if someone could confirm this.

Christophe

[mmorse]

That full of 1 user doesn't affect a full of all the others. (The accounts.xml has a latestFullBackupLabel for everyone and that will be used if you do a zmrestore -f without picking a particular label -lb.) Thus you can feel free to kickoff a full of 1 account at any time: zmbackup -f -a user@domain.com

Just make sure you understand CLI zmrestore restoreToTime Network Edition only - Zimbra :: Wiki
So if your restoring an account, you do an -lb argument to specify a full backup for the account that took place prior to the time period you wish to restore.

~

See all sorts of other options in: CLI zmrestore Network Edition only - Zimbra :: Wiki

(And it never hurts to do a "-ca -pre restored_" to create a new target account to test the restore on first.)

More on auto-grouped (for large systems), zmplayredo, and -zip which ended up being the default mode in 6.0 here: Recent Admin Backup Tidbits - Part 1 » Zimbra :: Blog

[LMStone]

Originally Posted by hispa

full backups are done once a week, and the others day it only makes incremental backups that are the differences between the last backup until the moment it begins to backup.

Full backups are a set of incremental backups joined together.. how can it be than an incremental backup is larger in size than a full backup? i don't get it.

Thanks.

Incremental backups move the redo logs into the ~/backup tree; full backups leave the redo logs where they normally live.

Regardless, it's easy to test if your full backups are OK by doing a restore with a prepended account name. Assuming you test with your own account, just do a "View Mail" on the restored account from the Admin Console and see if everything that you thought should be there is indeed there.

Hope that helps!
Mark

[mertz]

Originally Posted by mmorse

That full of 1 user doesn't affect a full of all the others. (The accounts.xml has a latestFullBackupLabel for everyone and that will be used if you do a zmrestore -f without picking a particular label -lb.) Thus you can feel free to kickoff a full of 1 account at any time: zmbackup -f -a user@domain.com

Just make sure you understand CLI zmrestore restoreToTime Network Edition only - Zimbra :: Wiki
So if your restoring an account, you do an -lb argument to specify a full backup for the account that took place prior to the time period you wish to restore.

See all sorts of other options in: CLI zmrestore Network Edition only - Zimbra :: Wiki

(And it never hurts to do a "-ca -pre restored_" to create a new target account to test the restore on first.)
.....

thx for your reply... very enlightning for me, an testing it as you described is nice.

christophe