EMC PowerPath limitations of Veeam Agent for Linux

If a Linux server has EMC PowerPath devices attached, all the underlying block devices representing the network paths to the server are skipped from processing. This will result in the error "No objects to backup" or PowerPath devices missing from the backup. If non-PowerPath devices are part of the backup scope (i.e., the Entire Computer scope is selected), the backup will technically be green, but the PowerPath devices will be silently skipped.

Veeam Agent for Linux detects only the DM-Multipath-based devices as aggregated. Additionally, block devices with the same MBR/GPT ID cannot be backed up. Because of this, both individual paths and aggregated devices are considered different block devices and are skipped from processing.

EMC PowerPath support will be introduced in future versions of Veeam Agent for Linux.

You must exclude all individual IO paths using the ignoreDevices parameter within the /etc/veeam/veeam.ini configuration file. The ignoreDevices parameter must be manually created under the [backup] section of the veeam.ini file.

 

Example

1. Using the command powermt display dev=all to list the EMC PowerPath aggregated device name and underlying devices.
   ^{For more information about powermt and PowerPath CLI, please review: CLI and System Messages Reference}
   

   [root@localhost ~]# powermt display dev=all
    
   Pseudo name=emcpowerea
   Symmetrix ID=000343607604
   Logical device ID=07BA
   Device WWN=60000980000262604497023030364553
   state=alive; policy=SymmOpt; queued-IOs=0
   ==============================================================================
   --------------- Host ---------------   - Stor -  -- I/O Path --   -- Stats ---
   ###  HW Path               I/O Paths    Interf.  Mode     State   Q-IOs Errors
   ==============================================================================
      6 lpfc                   sdef       FA 10f:00 active   alive      0      0
      5 lpfc                   sdcm       FA  6f:00 active   alive      0      0
      4 lpfc                   sdau       FA  7f:00 active   alive      0      0
      3 lpfc                   sdb        FA 11f:00 active   alive      0      0
   

   In this example, there are the following devices:

   • /dev/emcpowerea — aggregated EMC PowerPath device
   • /dev/sdef, /dev/sdcm, /dev/sdau, /dev/sdb — underlying block devices representing the network paths

    

   Accordingly, the mount table lists /dev/emcpowerea device mounted under /data folder:
   

   root@localhost:~# mount | grep emcpowerea
   /dev/emcpowereap1 on /data type ext4 (rw,relatime,errors=remount-ro,stripe=256,data=ordered)
   

    

2. From the example above, the following is a formatted list of individual IO paths for the /dev/emcpowerea block device:

   /dev/sdef;/dev/sdcm;/dev/sdau;/dev/sdb
   

3. Specify those paths with the ignoreDevices parameter created under the [backup] section of the veeam.ini file. Use a semicolon without whitespace as a separator.
   
   Example:

   [backup]
   # Backup cluster alignment logarithm
   # clusteralign= 3
    
   # Ignore inactive LVM logical volumes during backup
   # ignoreinactivelvm= false
    
   # IO rate limit, from 0.01 to 1.0
   # ioratelimit= 0.9
    
   # CPU priority for veeamagents, from 0 to 19
   # priority= 10
     
   # Verbose logging of device enumeration
   # verbosedevenumlogging= false
    
   ignoreDevices= /dev/sdef;/dev/sdcm;/dev/sdau;/dev/sdb
   

4. Save the veeam.ini file and ensure no backup or restore sessions are running on the Veeam Agent machine. If no backup or restore sessions are running, restart the veeamservice daemon to pick up the new values from the configuration file.

   systemctl restart veeamservice
   

   or

   service veeamservice restart