VMRC becomes unresponsive when attempting to mount an ISO file that is mounted to too many virtual machines

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:

When mounting an ISO volume to a virtual machine, you experience these symptoms:

• Some virtual machines fail to start, while others on the same Port Group remain unaffected.
• The Virtual Machine Remote Console (VMRC) becomes unresponsive to command.
• Ping requests fail or succeed with huge latency.
  
  For example:
  
  Pinging xxx.xxx.xxx.xxxx with 32 bytes of data:
  Reply from xxx.xxx.xxx.xxxx: bytes=32 time=3438ms TTL=60
  Request timed out.
  Reply from xxx.xxx.xxx.xxxx: bytes=32 time=2547ms TTL=60
  Request timed out.
  
  
• In the virtual machine's vmware.log file, you see messages similar to:
  
  ide0:0: Command TEST UNIT READY took 4.041 seconds (ok)
  TESTVM: Failed to open '/vmfs/volumes/524be099-79433ba4-f717-0090fa27f4cc/ISOs/TESTDISC.ISO' : Too many users (22274) (0x2001).
  CDROM-IMG: image open for '/vmfs/volumes/524be099-79433ba4-f717-0090fa27f4cc/ISOs/TESTDISC.ISO' failed: Too many users (22274)

Environment

VMware ESX 4.1.x
VMware ESXi 4.1.x Embedded
VMware ESXi 4.1.x Installable
VMware vSphere ESXi 5.0
VMware vSphere ESXi 5.1
VMware vSphere ESXi 5.5

Cause

When the ISO is mounted in a virtual machine running on an ESXi/ESX host, a file lock is maintained on the ISO file. Each host connection to the file consumes one lock. There is a maximum of eight locks possible for a file residing on a VMFS 3 datastore. This limits the amount of virtual machine hosts that can access a disk to a cluster of eight ESX/ESXi hosts. This restriction applies to virtual disk (VMDK) files, ISO CD/DVD images, floppy images, or any other file.

Note: The number of virtual machines running on the hosts and accessing the same virtual disk can exceed eight.

For more information, see VMFS File Locking and Its Impact in VMware View 5.1.

Resolution

To work around this limitation, use one of these options:

• Upgrade the hosts to ESXi 5.1 or later and VMFS to version 5.
  
  
• For more information on updating to VMFS 5, see Frequently Asked Questions on VMware vSphere 5.x for VMFS-5 (2003813)
  
  
• Check all hosts that have access to the VMFS 3 datastore that contain the ISO for a virtual machine or template with the ISO file mounted. Unmount the file to release one lock, so that you can mount the file on a different host. After removing the lock, connection to the virtual machine responds again and the error messages ceases.
  
  
• Unmount the ISO file from all locations and migrate the file to an NFS datastore. There are no file locking limits on NFS datastores.

Additional Information

For additional information on file locking issues, see Understanding the VMkernel log message: FS3: Reached maximum number of holders (1015797). Understanding the VMkernel log message: FS3: Reached maximum number of holders
既に数多くの他の仮想マシンにマウントされている ISO ファイルをマウントしようとすると、仮想マシンのリモートコンソールが応答しなくなる