5 1 0:VMware Backup

From SEPsesam

Welcome to the latest SEP sesam documentation version 5.1.0 Apollon. For previous documentation version(s), check documentation archive.

Virtualization Are you looking for an alternative for your VMware environment?

SEP supports a range of hypervisors, offering snapshot-based online backup of VMs.

Click HERE to get an overview of the available SEP modules and explore supported features like CBT, Single File Restore, and more.


Quick setup
  1. Linux specific: Install VMware VDDK on SEP sesam data mover (SDM-VV) on Linux.
  2. Install SEP sesam to a data mover.
  3. Select the relevant transport mode.
  4. Configure a vCenter Server as a SEP sesam Client.
  5. Configure a standalone ESX Server as a SEP sesam Client without vCenter Server.
  6. Configure the VM backup.

SEP sesam provides efficient data protection for virtual machines (VMs) running on VMware ESXi servers by using VMware vSphere Storage APIs – Data Protection (formerly known as VMware vStorage APIs for Data Protection or VADP).

The vSphere Storage APIs - Data Protection is included in all vSphere editions and kits. If a storage network environment (SAN) is properly configured, SEP sesam can perform LAN-free, centralized virtual machine backups without involving backup tasks to be run from inside each virtual machine on the ESX host. Off-host backup off-loads backup processing from the ESX server and thus also reduces costs, as each ESX host can run more virtual machines. SEP sesam provides simultaneous backup of a large number of virtual machines on SAN connected ESXi hosts.

SEP sesam VMware backup

SEP sesam uses VMware vSphere Storage APIs to create to create a consistent backup of the virtual machine. It requests a snapshot of the VM and backs up the complete virtual machine or individual virtual machine disk (VMDK) files to SEP sesam Server or SEP sesam Remote Device Server (RDS) directly over SAN to avoid network traffic. For an application-consistent backup, the quiescence snapshot option is used. When Changed Block Tracking (CBT) is enabled, SEP sesam provides a fast and efficient backup by backing up only those blocks that have changed since the last incremental or full backup.

It is also possible to specify additional options, such as shutting down a VM before backup or specifying the transport hierarchy, by using Backup options in the properties of the backup task.

For the list of supported VMware versions, see support matrix.

If you have just upgraded SEP sesam to version 5.0.0.x, which uses the enhanced LIS file format to improve performance, you should perform a new full vSphere backup to enable mounting and attaching VMDKs.
  • By using the integrated Si3 target deduplication for VMware backups, you can benefit from reduced disk capacity and increased overall storage performance.
  • Whenever a new vCenter or ESXi host is added and there is a lot of new VMs present that need to be backed up, you can automate the backup of VMs by including VMs to task groups according to the selection filter and automating the operation of creating backup tasks for VMs. For details, see Automating Backup Process.


  • SEP recommends a SEP sesam volume license which is based on the data volume per front-side terabyte and on the utilisation of SEP database agents. The volume license includes unlimited use of clients, hypervisors, disk storage, tape, Si3 deduplication and replication. For more details on volume licensing and front-side capacity calculations, see SEP volume licensing.
  • Because SEP sesam integrates with VMware vSphere Storage APIs – Data Protection, you need at least a VMware vSphere Essentials license.

Key features

  • VMware CBT support: copy, full, differential and incremental image-level backups of VMware virtual machines for storage optimization, single file restore and instant recovery (IR). See VMware single file restore & instant recovery support matrix for details.
  • Complete protection of VMware resources: vCenter Servers (VMs in the vCenter environment are discovered automatically) or individual vSphere ESX/ESXi servers can be added as a client to the SEP sesam environment.
  • Support for all VMware transport modes for backups and restores: SAN, HotAdd, NBD and NBDSSL are supported and their priority can be adjusted (see Selecting a VMware transport mode).
  • By using an SI3 NG deduplication store, redundant data blocks can be eliminated thus reducing the size of the backed up data.
  • Flexible restore can be performed using the GUI restore wizard or via the web interface Restore Assistant, which is more intuitive and offers additional advanced restore options. For details, see VMware Restore.


To ensure error-free operation of SEP sesam and improve performance, make sure that the following conditions are met:

Configuring your VMware system as a SEP sesam Client

Depending on your VMware environment (single server or cluster), some steps differ when configuring a client. Follow the appropriate procedure below.

Configuring vCenter Server as SEP sesam Client

To protect your virtual machines, you need to configure the VMware Virtual Center server as SEP sesam Client. SEP sesam supports the following vCenter types:

  • vCenter appliance from VMware
  • vCenter installed on a Windows Server environment

The procedure for configuring vCenter Server may differ slightly depending on your SEP sesam version.

  1. From Main Selection -> Components -> Clients, select your location and click the New Client button. The New Client window opens.
  2. In the New Client window, enter the DNS name of the vCenter server.
  3. From the drop-down list of configured locations, select a location to which you want to add a new client.
  4. From the Platform drop-down list, select the appropriate platform. The Operating system is automatically selected.
  5. Define your client as a vCenter server; select Virtualization server and then vCenter from the Virtualization server type drop-down list. Note that the access mode PROXY is automatically selected.

  6. Click the tab vCenter Access and enter vCenter credentials with highest administrator rights.
  7. Then select a Data mover.
    The VMware backup performance is highly dependent on the transport mode. To check the recommendations for the optimal data mover, see Selecting the best VMware transport mode for your environment.

  8. Click OK to add the new client.

Configuring a standalone ESX Server as a SEP sesam Client without vCenter Server

In case no vCenter is available, the ESX server itself can be added to SEP sesam.

  1. From Main Selection -> Components -> Clients, select your location and click the New Client button. The New Client window opens.
  2. In the New Client window, enter the DNS name of the ESX server.
  3. From the drop-down list of configured locations, select a location to which you want to add a new client.
  4. From the Platform drop-down list, select UNIX and then select the ESX-Server. When selected, all other required options are set automatically and cannot be changed.

  5. Click the tab ESX Server Access and enter ESX server credentials with administrator rights.
  6. Then select a Data mover. Note that the optimal data mover depends on storage type and selected transport mode. For details on which data mover is optimal, see Selecting a VMware transport mode.

  7. Click OK to add the new client.

Creating a backup task

You can use different SEP sesam data stores (Path, Si3 deduplication data store, HPE StoreOnce, etc.) for your Vmware VM backup.

SEP sesam cannot back up the data on the independent or RDM disks, due to a VMware limitation that does not support including independent/RDM disks in virtual machine snapshots; a warning about the missing data is issued. If a restore of a VM with an external disk is performed to the original VM by using the option Overwrite, the disk is re-created and all existing data on the restore target is lost.

To back up VMs that contain independent disks or RDMs, you should exclude the independent disks/RDMs from the backup task or install a SEP sesam Client in the virtual machine and perform an additional file or application backup to back up this data.

For general information on backup configuration and prerequisites, see Standard Backup Procedure. This section deals only with VMware-specific information.

  1. From Main Selection -> Tasks -> By Clients, select the vCenter client and click New Backup Task. The New Backup Task window opens.
  2. Specify the Source. Browse for the VM that you want to include in the backup and select it. Note that you can only configure one VM per backup task. By selecting the source, the task type and task name are set automatically.
  3. Note
    The Client Browser (Client File View) displays VM-related metadata details, such as server name, memory, host name, etc., and under Description information whether and how often this item is already covered by backup tasks. In the Details column, you can check and copy the details of the selected item, i.e. VM, host, etc.

  4. Optionally, in the Exclude list select one or more VMDKs that you do not want to back up by using the big browse button (next to the fields Source and Exclude list) and selecting your source for exclude. In our example, we have excluded one VMDK, as shown in the screenshot below.

    Using symbolic exclude
    If the number of VMDKs to be excluded for backup exceeds allowed length, you can use the symbolic exclude, as shown in the following example.
    Note that specifying the exclude list by using the symbolic names is not the recommended procedure and should only be used if you know what you are doing.

    The symbolic names reference the order of VMDKs of virtual machine definition. In our example we have 13 disks as a backup source, as shown in the screenshot below.

    The first virtual disk is usually SCSI0:0, the second is SCSI0:1, and so on. The vmdk0 would exclude SCSI0:0, the vmdk1 would exclude SCSI0:1, etc. Note that if SCSI0:1 does not exist, the second disk would then be SCSI0:2 and the vmdk1 would exclude this second disk (SCSI0:2). However, if you later add a new disk SCSI0:1, then vmdk1 would exclude the newly added disk SCSI0:1 rather than previously specified SCSI0:2, because SCSI0:2 would now be the third disk.

    If you want to add a comment, enter it in the Notes field.
  5. Use the following options carefully.

    • Execution off: If this task needs to be excluded from the backup for technical or other reasons, you can deactivate it by checking this option. If this option is set, the backup of this task will not start until it is unlocked again, even if it is scheduled for backup. For details, see Disabling and Enabling Backup Task.
    • If the Backup as image option is enabled, a FULL raw backup of VMDK without CBT is performed, even though the CBT is selected. However, CBT is applied for consecutive differential and incremental backups. If Backup as Image option is deselected while the CBT stays enabled, the CBT is fully utilized. For details on how the combination of these options affects the size of your backed up data, check VMware single file restore & instant recovery support matrix.
    • Unlike previous versions, it is now possible to prevent all data from being stored in a single saveset when performing COPY backups. If the option When running with backup level 'COPY', write all data to a single saveset (no mounting possible) is disabled while the CBT remains enabled, the CBT is fully utilized. For details on how the combination of these options affects the size of your backed up data, check VMware single file restore & instant recovery support matrix.
    • If you want to exclude a dedicated virtual disk (VMDK) from snapshot operations and backup only VM configuration, select the Backup only the VM configuration check box. In this case, only Open Virtualization Format (OVF) file and VM configuration are backed up.
    • By default, Changed Block Tracking option is enabled. For details, see Changed Block Tracking (CBT).
    • Note
      Resetting CBT requires administrator privileges.
  6. Optionally, switch to the Options tab and enter additional options in the Backup options field:
    • You can specify a transport hierarchy for your VMware backup job by entering the preferred order. For example, -a trans=hotadd:san:nbd:nbdssl will define the order as HotAdd (preferred transport mode), then SAN, followed by NBD and NBDSSL.
    • You can also define whether you want to quiesce the VM file system. Quiescing a file system is a process of bringing the data on disk into a consistent state suitable for backups. VMware Tools work with Microsoft Volume Shadow Copy Service (VSS) to quiesce applications before they are backed up. For this, the <quiesce> flag must be set to 1 (or true).
      • To enable quiescing, enter the following in the Backup options field: -a qui=1.
      • To disable quiescing, enter the following in the Backup options field: -a qui=0.
      If you want to specify more commands, for example, set the above transport hierarchy and quiescing, simply enter the options one after another, for example: -a trans=hotadd:san:nbd:nbdssl -a qui=1.
      Alternatively you could merge the -a options together using comma: -a trans=hotadd:san:nbd:nbdssl,qui=1. Note that you have to use a comma without spaces to separate the commands.
    • You can also chose to shut down a VM before the snapshot is created, as described in the section Shutting down VM.
    • For the list of actions you can use for a VM backup refer to Available sandbox actions.
  7. Optionally, click the corresponding tabs in the New Backup Task window to define additional options. Then click OK to create the task.

You can group your backup tasks to task groups. For details, see Adding a Task to the Task Group.

Plan your backup schedules carefully. It is recommended to balance your backup schedules to even out the resource usage: for example, schedule a greater number of VMs on the same host or the same LUN to run consequently rather than concurrently. For details, see Creating a Schedule.

The final step in the backup configuration is creating a new backup event. For general information, see Creating a Backup Event. For VM backup the following backup levels are available:

  • COPY: Uses CBT to back up the entire VMDK unless the option When running with backup level 'COPY', write all data to a single saveset (no mounting possible) is enabled.
  • FULL: Uses CBT to back up only used blocks of VMDK files, located on a VMFS volume. In combination with the option Backup as image, a full raw backup of VMDK without CBT is performed, even though the CBT is selected. However, CBT is applied for all subsequent differential and incremental backups.
    Full backup cannot be performed for VMDKs that are stored on NFS volume.
  • INCR and DIFF: Uses CBT to get the list of blocks that have changed since the last run of this backup task and backs up only the changed blocks of data. A full VMDK backup is required before you can create incremental/differential backups.
To protect VMware virtual machines and enable a smooth restore, it is recommended to use a seven-day rotation with differential and incremental backups, where a full backup is run over the weekend every 7th day. This helps you ensure safety of backup data and avoid long chains of incremental/differential backups. For details, see Backup Strategy Best Practices.

Finally, run the VM backup.

You can view the status of your backup jobs in the GUI (Monitoring -> Last Backup State or Job State -> Backups) or SEP sesam Web UI. The backup status overview provides detailed information about the last run of backup jobs, including the task name, start and stop time of the last backup, backup level, data size, throughput, assigned media pool, etc.

Recommendations for backing up a vCenter Server

  • The vCenter backup should run every day via vSphere backup. This backup task must run exclusively at the time when no other vSphere backups are active!
  • If a vCenter server is a physical host, it is highly recommended to schedule daily SEP sesam BSR Pro – Backup Configuration, file and MS SQL backups.

Shutting down VM

For application-consistent backup and consistent state of the complete VM, you can shut down the VM before the snapshot is created and backup is performed. You have to enter the following option when creating a backup task, under the Options tab in the Backup options field: -a action=stop.backup.start. Once the backup is completed, the VM is started automatically.

Available backup actions

SEP sesam supports the following actions that can be used for VMware backup. For additional actions that are available for VMware see also Available sandbox actions.


This command starts the given actions on the running virtual machine using the VMWare guest tools. The precondition to use the action command is that the virtual machine boots and has the VMWare guest tools installed and running. The command will either succeed or log the cause of the failure.

In case an action command is not specified, SEP sesam VMware backup executes actions snap.backup.dele by default.

The general action syntax is:


The actions can be combined with the "." (dot) as the separator between the steps. Note that the run action can appear multiple times within the action command sequence. The options, customizing the action behavior, are separated by "," (a comma).



In this example the following actions are executed:

  1. Start VM (start).
  2. Run script (run=/tmp/gt).
  3. Create snapshot (snap).
  4. Back up VM (backup).
  5. Run script (run=/tmp/gt2).
  6. Delete snapshot (delsnap).

The table below contains available actions.

Action Syntax Description
snap -a action=snap Create the VM snapshot
backup -a action=backup Back up the VM
run -a action=run=<script> Run a script directly on VM
crea(te) -a action=crea Create a snapshot of the VM
dele(te) -a action=dele Delete a snapshot of the VM
delsnap -a action=delsnap Delete a snapshot of the VM. If combined with snapdelete=<days> is specified, snapshots that are older than <days> are deleted.
snapdelete -a action=delsnap.snapdelete=<days> Delete VM snapshots that are older than <days>.
alld(elete) -a action=alld Remove all SEP sesam snapshots of the VM
deletebefore -a action=deletebefore Delete a snapshot of the VM before the backup starts
dele(te)_after_<n><min|sec> -a action=delete_after_<n><min|sec> Delete the snapshot of the VM after <n> seconds or minutes
cbtf(iles) -a action=cbtf Create the CBT information files for FULL, DIFF and INCR backups. For CBT backups, this action is automatically included.
cidf(ile) -a action=cidf Create the CBT information files for DIFF and INCR backups. For CBT backups, this action is automatically included.
cbt0|cbt1 -a action=cbt0
-a action=cbt1
Disable (with cbt0) or enable (with cbt1) CBT for the VM
resetcbt -a action=resetcbt Hard reset the CBT information for the VM (with additional snapshot revert)
softresetcbt -a action=softresetcbt Reset the CBT information for the VM
start -a action=start Start the VM
stop -a action=stop Stop the VM
restart -a action=restart Restart the VM
shutdown -a action=shutdown Shut down the VM
exec -a action=exec=<script> Run an external command, which must be located in sepsesam/bin/sesam
sleep -a action=sleep=<seconds> Specify wait time in seconds
check -a action=check=<condition> Test if a VM property matches specified condition

What is next?

Automating Backup ProcessVMware RestoreVMware Single File RestoreVMware Instant RecoveryVMware Sandbox Restore

See also

VMware Backup Using Hardware Snapshots - Changed Block Tracking (CBT)VMware Advanced ConfigurationTroubleshooting

External references

Copyright © SEP AG 1999-2024. All rights reserved.
Any form of reproduction of the contents or parts of this manual is allowed only with the express written permission from SEP AG. When compiling and designing user documentation SEP AG uses great diligence and attempts to deliver accurate and correct information. However, SEP AG cannot issue a guarantee for the contents of this manual.