Vmmaxbackupsessions

An optimized backup operation is one in which parallel backup capability is enabled at the VM, virtual disk, or subdisk level.

The vmmaxbackupsessions option works with the vmmaxparallel, vmlimitperdatastore, and vmlimitperhost options to optimize backup operations and to help control the amount of resources that the backup can create on a host in the vSphere infrastructure. Adjust the values of these options to find the values that provide optimal performance for the backups that are in your environment.

Supported clients

This feature is available only if the client operates as a data mover for IBM Spectrum Protect for Virtual Environments: Data Protection for VMware.

This option can be used with supported x86_64 Linux clients.

This option can be used with supported Windows clients. This option is not valid for Data Protection for Microsoft Hyper-V backups.

Syntax

                           .-vmmaxparallelvalue-.   
>>-VMMAXBACKUPSEssions-- --+-+---------+--------+--------------><
                             '-integer-'            

Parameters

integer

Specifies the maximum number of IBM Spectrum Protect server sessions that can be created during the backup operation.

Review the following information for using the vmmaxbackupsessions option along with the vmmaxparallel option or the maxnummp server parameter:

vmmaxparallel

The vmmaxparallel option specifies the maximum number of virtual machines that can be backed up to the IBM Spectrum Protect server at any one time. The value of the vmmaxbackupsessions option must be equal to or greater than the value of the vmmaxparallel option.

If the value is less than the value of the vmmaxparallel option, the following message is returned and the value is changed to the same value as the vmmaxparallel option:

ANS9995W The value of the VMMAXBACKUPSESSIONS option is number_value. This value must be greater than or equal to the value of the VMMAXPARALLEL option, which is number_value. The value will be set to the value of the VMMAXPARALLEL option.

maxnummp

The maxnummp server parameter specifies the maximum number of mount points a node is allowed to use on the server when the copy destination of the storage pool is FILE or TAPE. The maxnummp parameter must be equal to or greater than the vmmaxparallel and vmmaxbackupsessions option settings. When multiple instances of the client are backing up files, or when a single client performs parallel backups, more mount points might be needed.

If the values for vmmaxparallel or vmmaxbackupsessions exceed the value for maxnummp, ANS0266I and other messages are displayed. Depending on the message, the client reduces the value of the vmmaxparallel option to match the number that is specified by maxnummp parameter or prohibits additional sessions from being opened for the specified VM. In either situation, the backup operation continues.

If additional ANS0266I errors are detected, the client reduces the vmmaxparallel value by 1 and attempts to continue the backup. If vmmaxparallel is decremented to 1 and the client receives more ANS0266I errors, the client ends the backup and issues the following error:

ANS5228E A backup VM operation failed because VMMAXPARALLEL was reduced to 1 and the client still cannot obtain a server mount point.

Contact your server administrator if you want the value that is currently set for maxnummp increased so your node can support additional parallel backup sessions.

On Windows Server 2012 and 2012 R2, during Hyper-V virtual machine backups, IBM Spectrum Protect creates VSS snapshots of all volumes that contain virtual machine data. Backup data is read from the VSS snapshots, and not from data that is on the live file system. In many cases, when IBM Spectrum Protect attempts to create several snapshots concurrently, the VSS software provider might fail to satisfy a snapshot request for several virtual machines. The failures occur because the VSS software snapshot provider can not handle the load that is created by several backups that are attempted in parallel. To avoid this issue, use a VSS hardware snapshot provider instead of a VSS software provider.

The maximum that you can specify is 100 sessions. The default is the value that is set for the vmmaxparallel option.