Yosemite Xsan clients may not mount volumes if they exceed max connections

Xsan volumes created with Server 4.0 default to a maxConnections value of 10.

This article has been archived and is no longer updated by Apple.

Before you begin

This article applies to volumes created with Server version 4.0. Volumes created with Server 4.0.3 or later are not affected by this issue.

Volumes created with OS X Server v4.0

Xsan volumes created with Server 4.0 default to a maxConnections value of 10. Additional clients are unable to mount the Xsan volume or make other connections to the volume's controller when the maxConnections limit is reached.

When this happens, the volume's cvlog (located in /Library/Logs/Xsan/data/volumeName) reports an error like the following:

(**Error**) Number of connections: (11) would exceed max connections (10)

To increase the maxConnections value for a volume, do the following on one of the volume's metadata controllers:

  1. Make a backup copy of the volume's current .cfgp file from the /Library/Preferences/Xsan folder.
  2. In Terminal, enter the following command to check for an existing maxConnections value, replacing "volumeName" with the name of your volume:
    sudo /usr/libexec/PlistBuddy -c "Print :config:globals:maxConnections" /Library/Preferences/Xsan/volumeName.cfgp
    

    If the command reports that the value does not exist, continue to the next step. If the command reports a number, then a value has already been set for the volume and you do not need to proceed.

  3. Enter the following command to add a maxConnections value of 256, replacing "volumeName" with the name of your volume:
    sudo /usr/libexec/PlistBuddy -c "Add :config:globals:maxConnections string 256" /Library/Preferences/Xsan/volumeName.cfgp
    
  4. Enter the following command to propagate the new configuration for the volume to other Xsan metadata controllers.
    sudo xsanctl pushConfigUpdate
    
  5. Go to the Xsan pane in Server app, select the volume from the Volumes list, then choose Stop Volume from the gear menu at the bottom of the window.
  6. Once the volume status shows it's offline, choose Start Volume from the gear menu to restart the volume with the new maxConnections value applied.
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