Using the tagschedule option to rebalance scheduled operations

To optimize a tagged schedule operation, you can balance tagged schedules according to the size (total storage occupied) of the VMs in the selected schedule. By rebalancing tagged schedules, you reset which data mover processes each VM that is backed up by the schedule.

The vSphere Web client plug-in assigns data movers to VMs as they are added to a schedule. To rebalance tagged schedules by using the GUI, you must edit the schedule and ensure that the check box for rebalancing the schedule is selected upon saving. VMs are added to schedules by other means. For example, new VMs are also assigned data movers after the first backup by the default data mover. You may want to periodically issue a full rebalance. The advantage of rebalancing tag schedules is that backups are distributed evenly across storage resources. This can be done with the vSphere Web client plug-in or by using the data mover command-line interface.

Re-balance operations are rarely necessary. VMs are balanced when they are added to a schedule and new VMs are also assigned balanced data movers. A full rebalance operation might be required when a significant number of VMs are deleted or moved. Use the VMREBALANCESCHEDULEONLY option when you need to rebalance all data movers and VMs associated with a schedule.

To automate rebalance operations, a VMREBALANCESCHEDULEPERIOD option can be manually added as a parameter on the schedule option string, or in the options file. Although you can place the option in the default data mover's option file, it is preferable to add the option to the OPTion string of the schedule. In this way, you can avoid ambiguity if one data mover services multiple schedules.

Specify the VMREBALANCESCHEDULEPERIOD option only if the schedule has multiple data movers assigned. The option will be used only by the default data mover. A default data mover is assigned when adding data movers to a schedule. The schedule is rebalanced after the number of days specified by the VMREBALANCESCHEDULEPERIOD option and only after the schedule has completed its current backup operation.

Syntax


>>-TAGSCHEDule=--schedule_name-- -VMREBALANCESCHEDULEONLY------->

>-- -ASNODENAME=--datacenter_name------------------------------->

>-- -OPTFILE=--datamover_option_file_name----------------------><

Parameters

-VMREBALANCESCHEDULEONLY: Use this parameter to balance data movers in tag schedules according to the size of the VM. Data movers are assigned to the VMs by size, with the largest VM being assigned to the first data mover on the list, the next largest VM assigned to the next data mover, and so on. Existing data mover assignments are overwritten by reassigning the data mover tag on each VM.
-VMREBALANCESCHEDULEPERIOD: Use this parameter in the options file to specify the time (in days) between rebalancing operations by the client. You can specify a value in the range 0 to 365. If you specify 0, which is the default, rebalancing never occurs. If you specify 365, rebalancing occurs about once a year. The scheduled rebalance operation is run on the default data mover.
-ASNODENAME: Use this parameter to specify the name of the data center.
-OPTFILE: Use this parameter to specify the name of the options file.

Examples

Command line:: dsmc backup vm -OPTFILE=dsm.MM1_DATACENTER1_DM1.opt -tagschedule=VMWARE01 -vmrebalancescheduleonly -asnodename=MY_DATACENTER_NODE
Rebalances the schedule named VMWARE01, which targets the node MY_DATACENTER_NODE. After the rebalance operation, VMs that were asymmetrically assigned across data movers are now symmetrically assigned. VMs that were unassigned to data movers are now assigned.

The following output shows before and after scenarios for a rebalance operation for schedule named vmware_sxf1_cldev:

dsmc backup vm -tagschedule=vmware_sxf1_cldev -vmrebalancescheduleonly -asnode=sxf1_cldev
Node Name: DEFENDER1
Accessing as node: SXF1_CLDEV
ANS4313I Rebalance Schedule VMWARE_SXF1_CLDEV Type: Full

Before Rebalance
----------------
   Data Mover Name               : DEFENDER1
   Total Bytes Protected         : 432.16 GB
   Virtual Machines Protected    : 10

   Data Mover Name               : SXF1_CLDEV_DM
   Total Bytes Protected         : 116.04 GB
   Virtual Machines Protected    : 3

   Virtual Machines not assigned : 1

After Rebalance
----------------
   Data Mover Name               : DEFENDER1
   Total Bytes Protected         : 332.08 GB
   Virtual Machines Protected    : 7

   Data Mover Name               : SXF1_CLDEV_DM
   Total Bytes Protected         : 316.12 GB
   Virtual Machines Protected    : 7

   Virtual Machines not assigned : 0

The rebalance output information is recorded in the schedule log and logged to the server activity log.

UPDate SCHedule domain_name schedule_name OPTions="-vmfulltype=vstor
-vmbackuptype=fullvm -asnodename=sxf1_cldev -mode=IFIncremental 
-domain.vmfull=SCHEDULE-TAG -vmtagdefaultdatamover=DEFENDER1 
-vmrebalancescheduleperiod=1"

Specifies that the default data mover rebalances the schedule every day.