Archive:RHEV backup

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Overview

SEP AG offers a solution to perform snapshot based backups of virtual machines in RHEV (Red Hat Enterprise Virtualization) environments. This backup technology is developed together with Red Hat and uses components of the libvirt API to grant a consistent backup.

Key features

Supported Systems

• Red Hat Enterprise Linux Server 7

Backup level

For now, only COPY backup is supported for RHEV. With this backup all data defined by the backup task is backed up (provisioned space). Therefore it is recommended to use the SEP Si3 target deduplication for your RHEV backups. Note that other backup levels will be available soon.

By default the RHEV backup module creates fully memory aware snapshots of the virtual machine, if you want to disable memory snapshots you can add the additional option "-a qui=0" in the expert options.

Backup

• SEP sesam supports backup for RHEV single server and RHEV cluster with libvirt API.
• The backup of individual VMs is supported on RHEV single server as well as on RHEV cluster.
• The following backup methods are available for backing up multiple VMs in a RHEV cluster/data-center or RHEV single server:
  • A config only backup which backs up only the virtual machine configuration
  • Backup of individual VMs which can be grouped together in one task group running on multiple hosts via the RHEV Manager resource
    • Backup of VMs with specific disks (disk exclude)

Restore

• You can restore your VM to the original or different locations with the same or a different VM name using relocation.
• You can restore your VM to the same or a different single RHEV server as well as to the same or a different RHEV cluster.
• You can perform a simple path restore of your selected RHEV virtual machine configuration directly to a directory on any system rather than restoring and importing VM to the RHEV environment.

Limitations

• SEP sesam supports restore of only one VM at a time.
• Direct attached disks (via passthrought) are not supported.
• Only one virtual machine per task can be backed up
• Only FULL backup or configuration backup is possible currently
• Only RHEL7 can be used as data-mover for backups and restores.
• During restore the Virtual Disk will consume complete thick provisioned space on the target storage! In case you have backed up a 1 TB VM disk, 1 TB must be free on the target pool the VM is created on!

Prerequisites

• RHEL Version 7
• SEP sesam Server Version V4.4.3 or higher
• SEP sesam Client 4.4.3.x
• Working name resolution for RHEV nodes and the RHEV resource (RHEV Manager)
• Check the support matrix for the list of supported RHEV versions.
• Access to the RHEV management center (administrative user)
• For RHEV 4.0 and sesam versions <= 4.4.3.22 an additional servicepack has to be installed on the data-mover system:

https://www.sep.de/downloadportal/servicepacks/4.4.3/<release_version_number>/linux/sbc_proxy_d795ebc_x86_64_rhel7-4.4.3.22.tgz

	Note
	We recommend our customers to update to the latest RHEV stable version available. Older RHEV versions often have problems on snapshot consolidations which can lead to broken backups. Newer RHEV versions have gained more stability in this regard and are recommended to use.

Hardware

The following are the hardware requirements for the SEP sesam Server, RDS or SEP sesam Client. They are similar for both servers, SEP sesam Server and RDS, except for the required space on the file system for the SEP sesam database, which is not necessary for RDS.

• The hardware requirements for the SEP sesam components represent the common requirements. Additional amount of RAM/CPU may be required for bigger Si3 data stores. For details, see Si3 Deduplication Hardware Requirements.

• (Windows only) Make sure that you are using CPUs with supported AVX versions (AVX, AVX2, or AVX-512) and FMA3 (Fused Multiply-Add 3-operand Form) or FMA4 (Fused Multiply-Add 4-operand Form) to prevent the Sesam Transfer Protocol Server (STPD) from automatically disabling the HTTPS port. This happens when the CPU instructions are missing due to unsupported AVX. Consequently, the TLS key and certificate cannot be created. For a list of supported AVX versions, see Advanced Vector Extensions.

Requirements	SEP sesam Server Standard edition	SEP sesam Advanced Server edition	SEP sesam Premium Server edition	SEP sesam Enterprise Server	SEP sesam Client
Memory (without Si3 deduplication)	8 GB RAM	Minimum 16 GB RAM	32 GB RAM	Minimum 64 GB RAM	2 GB (recommended 4 GB)
Memory (with Si3 deduplication)	Minimum 32 GB RAM	Minimum 32 GB RAM	64 GB RAM	Minimum 128 GB RAM	Minimum 8 GB
Core (without Si3 deduplication)	1x CPU with 4 cores (≥ 2,4 GHz)	1x CPU with 8 cores (≥ 2,4 GHz)	Minimum 1x CPU with 8 cores (≥ 2,4 GHz)	Minimum 2x CPUs with 4 cores (≥ 2,4 GHz)	-
Core (with Si3 deduplication)	1x CPU with 6 cores (≥ 2,6 GHz)	2x CPUs with 8 cores (≥ 2,6 GHz)	2x CPUs with minimum 8 cores (≥ 2,6 GHz)	Minimum 2x CPUs with 8 cores (≥ 2,6 GHz)	-
Minimum hard disk space for SEP sesam metadata	200 GB	300 GB	500 GB	500 GB	4 GB (for all client data)
No. of backup clients	Up to 15	Recommended up to 50	Recommended up to 150	Recommended for more than 150	-

Functionality

Backup workflow

During the Backup the following workflow is happening

• A Snapshot of the virtual machine is created.
• Virtual machine configuration is exported from the snapshot and backed up as the first saveset stream.
• The virtual disks represented in the snapshot are attached to the data-mover virtual machine.
• The data of the virtual disks is backed up.
• The snapshot of the virtual machine is removed.

Restore workflow

• Virtual machine configuration is restored to the data-mover.
• Target Virtual machine is created based on the configuration.
• Target Virtual machine disks are created on the target storage domain.
• Provisioned disks are attached to the data-mover VM.
• Data of the disks is restored.
• Disks are re-attached from the data-mover VM to the Target virtual machine.

The following pictures show variants on how to use the backup module for lan or lan-free backup:

LAN or LAN-Free backup

To run a SEP sesam backup and restore in a RHEV environment with the RHEV API a SEP sesam Client is necessary. This functions as a SEP sesam DataMover (central communication element) between SEP sesam Server and RHEV Data-Center. Therefore a snapshot of the virtual machine is created during the backup process and mounted to the SEP sesam DataMover. The snapshots can be transferred via LAN or SAN (Storage Area Network). If a SAN storage device is available for SEP sesam, the transfer is done directly (LAN free).

The blue arrows in the illustration are showing the direction of the connection establishment for communication and metadata transfer.

The red arrows in the illustration are showing the direction of the connection establishment for data transfer to connected storages.

LAN based backup scenario

1. Start backup process with connection to the RHEV Manager host.

2. Create consistent snapshot of virtual machine with RHEV Manager backup API.

3. Mount snapshot to Sesam DataMover VM.

4. Transfer snapshot from Sesam DataMover VM to Sesam Server via LAN.

5. Store Snapshot on connected storage devices (Sesam DataStore, Sesam Si3 DedupeStore, Autoloader).

LAN based backup

LAN free backup scenario

1. Start backup process with connection to the RHEV Manager host.

2. Create consistent snapshot of virtual machine with RHEV Manager backup API.

3. Mount snapshot to Sesam DataMover VM (SEP sesam Remote Device Server) wich is direct connected to a storage device via SAN.

4. Transfer snapshot from Sesam DataMover VM (SEP sesam Remote Device Server) to connected storage via SAN.

5. Store Snapshot on connected storage devices (Sesam DataStore, Sesam Si3 DedupeStore, Autoloader).

LAN free backup

Installing RHEV Backup Client

In order to use the RHEV backup module a SEP sesam client with additional components must be installed on a virtual machine running RHEL 7 OS inside the RHEV environment.

Step

1. Install the downloaded SEP sesam client package on the RHEL 7 OS.

rpm -ihv sesam_cli-4.4.xxx.rhel7.x86_64.rpm

Preparation of SEP sesam Backup Server

Before you start with the configuration of the backup client the following steps have to be done to prepare the backup server.

Steps

1. Login via SSH and root rights to your backup server and source the sesam profile:

source /var/opt/sesam/var/ini/sesam2000.profile

2. Set the global variable for multi restore:

sm_glbv w gv_multi_restore 1

Configuring RHEV Backup Client as Data Mover

Now the virtual machine with installed sesam client must be added with the SEP sesam server GUI. This client acts as the data mover for backups.

Steps

1. In the Main Selection -> Components -> Topology, select the location of your choice (e.g. RHEV) and click the New client button. The New client window appears.

2. Enter the Client Name.

	Note
	The datamover must have the same name as the VM in RHEV has! Means the RHEV virtual machine name for the datamover must be the same as hostname for sesam client.

3. From the Platform drop-down list select Unix, and from the Operating system select Linux.

Click OK to add the new client.

Configuring RHEV Manager as Client

The RHEV Manager must be added as client.

Note:

It is not necessary to install a SEP sesam client on the RHEV Manager system.

Steps

1. In the Main Selection -> Components -> Topology, select the location of your choice (e.g. RHEV) and click the New client button. The New client window appears.

2. Enter the Client Name.

3. From the Platform drop-down list select Unix, and from the Operating system select Linux.

4. Change the Access Mode from CTRL to PROXY.

5. Change the VM Server Type to RHEV-Management-Server.

6. Select the RHEV Access tab and enter Account, Password and Data Mover.

Backing up RHEV Virtual Machines

Now we have to create new backup tasks for the RHEV Manager client.

Steps

1. In the Main Selection -> Tasks -> By clients, select the RHEV Manager client and then click New backup task. The New backup task window appears.

2. Specify the Source of the virtual machine you want to backup. By selecting the source, the task type and task name are set automatically.

Excluding Disks

Disks can be excluded by specifying the disks name in the exclude section of the backup task. As exclude the logical disk name as shown in the RHEV managment center has to specified in the exclude list. Multiple disks can be excluded by beeing seperated, example: "disk_name1,disk_name2"

Click OK to create the task.

3. If you want to start the newly created task immediately, right-click the name of the task and click Immediate start. If you want to schedule the task, click New schedule in the Main Selection -> Scheduling -> Schedules.

4. Check backup status in SEP sesam GUI under (Main Selection) Job State -> Backups.

Tip: You can also add your backup task to an already existing schedule by double-clicking the backup task, selecting the tab Schedules and adding it to one or more schedules.

Once you configured a schedule, you need to create a new backup event for it. Go to the Main Selection -> Scheduling -> New Backup Event, click the Parameter tab and select COPY backup from the Backup Level drop-down list. Note that COPY is the only supported backup level for SEP sesam RHEV clients! For more information on Schedules and related events, see Creating a Schedule.

Adding a task to the task group

Optionally, you can add your tasks for individual node or individual VM to a task group and enable triggering all tasks at once with a single event.

1. In the Main Selection -> Tasks -> By groups, click New task group. The New task group window appears.

2. Enter the Group name. Under the Tasks for this group select the tasks (from the list of all available tasks on the left) and add them to your newly created task group list.

3. If you want to start backups for the task group immediately, right-click the name of the task group and click Immediate start. If you want to schedule the task group, click New schedule in the Main Selection -> Scheduling -> Schedules.
Tip: If you already have a configured schedule, you can link your task group to it by clicking the Schedule tab in the Task group properties window.

Once you configured a schedule, you need to create a new backup event for it. Go to the Main Selection -> Scheduling -> New Backup Event, click the Parameter tab and select COPY backup from the Backup Level drop-down list. Note that COPY is the only supported backup level for SEP sesam RHEV clients! For more information on Schedules and related events, see Creating a Schedule.

Restoring RHEV Virtual Machines

Now we have to create new restore tasks for the RHEV Manager client.

Steps

1. Start the Restore Wizard from Main Selection and select the RHEV backup task you want to restore.

2. Select the RHEV backup saveset you want to restore.

3. Select the target virtual machine name you want to restore the virtual machine to.

4. Optionally, if the virtual machine should be restored with a different name select the option New restore Target and enter a different virtual machine name.
5. As of v. 4.4.3 Tigon, you can use the dd utility to create a thin-provisioned (sparse) disk file, thus restoring only the actual size of the VMs: Click the Expert Options button and enter the following under the Restore Options: -a use_dd


6. If you want to start your restore immediately, click Start. If you want to save the restore task, click Save.

	Note
	A restore task can be scheduled like any other task. If you want to add a restore task to the schedule, see Scheduling Restore.

You can view the status of your restore jobs by selecting Job state -> Restore from the Main selection. Restore overview provides detailed information on the last run of restore jobs, including the task name, status (successful, error, in queue ...), start and stop time of the last backup, data size, throughput, client and message.

Troubleshooting

For troubleshooting Red Hat Enterprise Linux issues, see Troubleshooting Red Hat Enterprise Linux.