NEtBackup and hotadd

[maxp69]

I have a problem with hotadd.

There is a way to limit the number of disk that can be added to a host?

The backup policy can limit only the number of the virtual machines that can be backupped at the same time, but I have many virtual machine with more that one disk. In this case netbackup try to add too many disks on the same media server and the backup crash. I've tried to add more controllers but the problem remains.

I would like to limit the number of disk that can be added. There is a way to do it?

Thanks,

Max

[rookie11]

I have nt really understood ur problem. So far i got ur taking backup of variours server which are virtual. ur taking backups via vcenter.

please elaborate " I have many virtual machine with more that one disk. In this case netbackup try to add too many disks on the same media server and the backup crash "

[maxp69]

I'm talking about vmware backup with hotadd.

I have a limit of 8 sessions on the storage unit. If i make a backup of 8 vitual machine with only 1 disk, on media server are attached 8 disks, but the if the virtual machines have for example 3 disks, on the media server will be attached 24 disks and the backup chrash.

[Michael_G_Ander]

The place to look is Resource Limit under the master server properties where you can limit a lot of things for vmware backups. Guess that hotadd would be affected by limiting Cluster and Datastore

http://www.symantec.com/docs/HOWTO70967 Info on the Resource Limit

[maxp69]

Hi Michael,

I've already checked but the limits are only for number of backups, and  a virtual machine with 10 disks it's a single backup.

[Marianne]

Why are you using hotadd?
Have you read up about all the requirements and limitations of hotadd?

Why not use Windows or Linux media server as backup host?

What is you NBU version and OS on Master/media server(s)?

VCentre/ESX version?

[maxp69]

Hi Marianne,

NBU is 7.6.1 and media servers are Windows 2008 R2 (I've tried also Windows 2012 and RedHat 6.5 but I have the same problems).

I cannot use SAN mode because I do not have a phisical host and NBD is too slow.

Vcenter and ESX are 5.5 update 2.

[Marianne]

You do not have a physical host??

Are you saying that all media servers are VMs?
(Not a good idea IMHO)

Have you gone through the Notes on the hotadd transport mode in NetBackup for VMware Administrator's Guide ? 
It contains a list of restrictions and requirements with links to VMware documentation.

[maxp69]

I've already checked but no luck.

The backup of 130 VM with only one disk works without problems. If I add to the job some VM with more that one disk (some VM has 8 or 9 disks) the backup chrash because the media agent has too many disk attached. It's a limit of netbackup with hotadd?

[RonCaplinger]

Is this the problem you have?

"HotAdd restore by Windows 2008 proxy when opening multiple disks.

• When a Windows Server 2008 virtual machine is deployed as a proxy, HotAdd failures can occur when writing to the second and subsequent disks of a virtual machine that is being restored. Due to SAN Policy changes, W2k8 R2 and W2k8 R2 SP1 are more prone to this than earlier editions. The cause: if COM function IVdsServiceLoader::LoadService is called soon after its interface was released by a previous iteration, the call might fail. There is no workaround. IVdsServiceLoader::LoadService can fail the second time when called rapidly in succession, and VMware code enumerates and mounts all disks the first time any disk is opened. A fix has been identified for availability in a future release."

[maxp69]

Hi Ron,

the problem is the backup, not the restore.

[Marianne]

You have not answered my previous questions:

You do not have a physical host??

Are you saying that all media servers are VMs?
(Not a good idea IMHO)

[maxp69]

Hi Marianne,

yes, I do not have any phisical host. All my media servers are virtual.

[Marianne]

All virtual media servers is probably not a good idea.

Have you seen this?

http://www.symantec.com/docs/HOWTO70878 

For Windows backup hosts, a backup that uses the hotadd transport mode fails if a vmdk file spans multiple disks. In this case, select a different transport mode for the backup. 
VMware has acknowledged this issue (SR#12204838207). This problem will be fixed in a future release.

More reading matter: 
http://www.symantec.com/docs/TECH183072

[maxp69]

Hi Marianne,

I've already checked but my problem is the number of disk attached to the proxy in hotadd.

With 1 or 2 concurrent jobs, the backup works without problems but it's too slow.

With 8 concurrent jobs, when the proxy has too many disks attached because some VM can have 7 or 8 disks, the backup crash. Always. And is not a problem of SCSI controllers because I have 4 SCSI constrollers.

[Marianne · Accepted solution]

You know the answer:

Select NBD or add physical media server as backup host.

[RonCaplinger]

Understood, BUT the info I posted was from a VMware forum that indicates there is a problem in VMware with mounting multiple disks, as you mentioned:

IVdsServiceLoader::LoadService can fail the second time when called rapidly in succession, and VMware code enumerates and mounts all disks the first time any disk is opened.

And VMware acknowledges its a problem but hasn't fixed it yet:

A fix has been identified for availability in a future release.

I think we're all saying the same thing, you will have to change your backup strategy, at least for now, in order to back up those VMs.