Can someone please tell me what the benefit (if any) is to performing a full backup on X day instead of performing constant incremental backups? We are new to Veeam but are starting to roll it out to quite a few of our clients. So far we are really pleased with it .
Regulatory compliance is pretty much the only reason to do periodic full backups. Some customers have requirements to perform full backups every day, basically this option is for them.
But for most customers, it is not needed. Forever-incremental is way to go - which is why it is disabled by default. We did not even have this option until v4, to start with
Manually initiated full backup is what may come handy sometimes, for example after changing job content settings and removing some VMs from the job.
Actually, there are many reasons to preform a full backup every now and then. Here's a few of my reasons:
1. Data Integrity/Safety -- While I generally trust the integrity of Veeam's backup files, when running "incremental forever" this increases the possibility that a single error in the "main" file can actually cause all previous backup to be "non-restorable". The cause of this corruption may or may not be the fault of Veeam itself. For example, the recent issue with CBT where a corner case could potentially cause all future incrementals to be invalid. Other scenarios might be a backup server or storage system crash that corrupts the "main" vbk. If you lose that single VBK file, all previous rollbacks are of no use.
2. Data Optimization/Removal -- At least with current generation Veeam products, if a VM is removed, it remains forever listed in your backup file, the only way to remove it is by running a full. This can happen even if a VM simply changes it's UID, which might happen if it's restored from backup or moved to a new cluster. We've also found that VBK files have a tendency to "grow forever" and running a full every so often generally results in a fresh VBK that's 5-10% smaller than the original.
3. Data Retention -- We've found that running a full backup can really be leveraged for data retention policies. Many companies like us have requirements to keep "monthly" backups for some period of time, and yearly backups for another period of time. For example, we generally keep 12 monthly backups and 3 yearly backups. We leverage our "full backups" to keep these monthly and yearly retentions by using a simple Linux script that is triggered from the Veeam backups which creates a "hardlink" of the file in a "Retention" folder. Veeam goes about it's normal retention policies and removes the full after 30 days, however, since there's a "hardlink" the file actually stays in the "Retention" folder. If we need to restore it we simply import it into Veeam. This way we don't have to have separate "monthly" and "yearly" jobs, and we never have to copy our VBK files around either.