VCB Backup types, file level, image - best option

[LeeClayton]

I know it's in the documentation but I'm trying to get a deffinitive answer on how netbackup does backups via VCB. I'm
talking about the different options when you create the Policy and select Snapshot client Options. You then have options from
0-3 to select the type of Virtual Machine Backup. I've created a table below of what I think from the documentation and some
testing these backups do. I'd appreciate if anyone can add/correct my findings

MS windows-NT policy

0-File - Backs up at a file level (Can do Full & Differential backups) - Restores at a file level

Flashbackup-windows

0-File - Backs up at a drive level (Can do Full & Differential backups) - Restores at a file level

1-FullVM - Backs up the full image only (Can do Full backups only) - Restores only the full image

2-MappedfullVM - Backs up the full image only (Can do Full backups Only) - Restores the full image & File Level

3-Fullvm and for file incremental - Backs up the full and incremental image (Can do Full & Differential backups) - Restores
Full image or File level

I tested the above on a windows server with 50GB of data and 90GB of usable disk space, the 0-File flashbackup-windows backup
only took 15 minutes, although it backed up all the 90GB of usable disk space whereas the ms windows-Nt backup to double 29 minutes.
The image style backups (1,2,3), all took over 50 minutes to backup - just cos it has to copy the image to the
proxy server 1st. I'm trying to work out which is the best way to backup my windows servers.
From what I've found, the only reason to do an image backup is if you require DR capability or you wish to restore complete
servers, am I right? For just file level restores 0-File seems to be the quickest option from my tests

I have another question --- am i right in thinking that the only difference between the Flashback-window backups  0-file & 3-fullvm incremental is that 0
-file does a mapping to the proxy and the 3-fullvm incremental copies the image to the proxy. In which case, 0-file will always be quicker and better to use.

[Karthikeyan_Sun]

As of my Checking this did matter !

0-File option cannot back up Windows system files or VMware
system files

You said 50 GB as the Data size but can divide them and tell me the size of user and os file sizes.

coming to 2nd question. Here is Symantec Answer !

For file-level backups (0-File), the VMware backup proxy server places a link
in this folder. The link points to the VMware virtual disk image that is
associated with the data files on the virtual machine. No virtual machine
data is copied to this folder.

And also for 3-Fullvm and for file incremental backup's- images will be copied to the mountpoint only in case of full Backup,

incremental backups of type 3; just a link is created to point to the original machine.

Let me know how clear you are from my answers :)

[LeeClayton]

It's the windows system files that 0-file does not back up so if I only care about data then it's not a problem, I'm not likely to do a system restore on a vm so I can live with that.
the 50GB data, probably 48GB was data I just copied on there.
so for 3-fullvm - the full backup copies the image to the vcb server but the incremental just creates a mount point?
As the ms-windows-NT policy backs up full and incremental and quicker I was also asking if this is my best option if I just want to back data up and not worry about restore full machines.

[Srikanth_Gubbal · Accepted solution]

From what I've found, the only reason to do an image backup is if you require DR capability or you wish to restore complete
servers, am I right? For just file level restores 0-File seems to be the quickest option from my tests

your understanding is right..

am i right in thinking that the only difference between the Flashback-window backups 0-file & 3-fullvm incremental is that 0
-file does a mapping to the proxy and the 3-fullvm incremental copies the image to the proxy. In which case, 0-file will always be quicker and better to use

option 3 will be usefull; when VM got corrupted.. if you have do not have that requirement for system files backup,you can go  for option 0

but one thing to say; netbackup gives end to end solution; it is how you use it.

[alazanowski]

Here is why I would always recommend number 3 (with a few exceptions of course)

1. A FullVM snapshot by itself WITHOUT being mapped is only useful if you
                                      a) need just the image for entire restores (not any individual file recovery within that full backup)
                                      b) You need to save on time doing the entire image and cannot afford the overhead required for mapping.
2. You don't want to use a File only version because again, you will not get any system files or vmware files (depending if you're the type who is okay with rebuilding a core server image first and then dumping add ons) but it will not contain any registry info as well.
3. Just doing the FullVM mapped  by itself regularly is useless - it just takes up space. With doing number 3, you are saying that it'll do the fullvm mapped first and then incrementals will be handled similar to the WindowsNT backup except that it DOES copy all the files that have been incremented first to the vcb.
4. If you use a FULLVM snapshot and want to restore a file, it doesn't take the same size as the entire snapshot compared to regular flashbackup.


You should understand that having the files and images copied over via san for performing the backups is VERY good when it comes to reducing the load taken by the backed up servers. If you run flashbackup or windows-nt backups directly on a system, you have to use that particular system's resources for this, versus a quick snapshot offload of the image that reduces performance impact.



Sometimes you'll actually have to choose a FullVM without being mapped or the file level only:
1. If the system that you are attempting to backup is EXTREMELY busy with using I/O load, there is the chance that a snapshot cannot occur (the system needs to be idled long enough for it to put a lock on the writes). Also, if theres not enough storage space on the VM for writing the extent of writes that occured during the snapshot, you can crash your VM.

I could think of more but my head would start to hurt.


Let me know if you need any more information, we mostly run VCB proxy backups here. Just remember, even thoguh the initial performance of a backup with just flashbackup only may be fast, if its not mapped and you have a disaster in which you need to restore some files, you have to restore the entire flashbackup image which takes more time versus when its mapped which would take only as long as it takes for those few files. All DR plans should be looked at in the sense of restore times, not necessarily backup times.

 

[Pravs]

Lee, I think you mean to say flashbackup-windows policy and type-0 Backup below?
>>>>As the ms-windows-NT policy backs up full and incremental and quicker I was also asking if this is my best option if I just want to back data up and not worry about restore full machines.

liked Outbacker's this comment- "All DR plans should be looked at in the sense of restore times, not necessarily backup times." so true.

[LeeClayton]

thanks for the replies, I think that's cleared everything up, it boils down to whether you NEED to perform image restores or just file level restores. Of course, with flashbackup and levels 2 & 3 you can do image and file level restores, it just takes more time to back up and will use a little more space (if lots of deletions on the vm has occured).

thanks for the info about 3Fullvm backup, I thought the full and incr backup image was copied to the proxy server, didn't know the incr backup just created a mount point/link, useful to know.