Configuring storage

There are two options to provide storage to the Virtual Machines (VMs) that will host the Cluster File System:

This deployment example uses VMDK files with the multi-writer option enabled. In this section we will show how to configure the ESXi server and virtual machines to share a VMDK file and how to configure SFCFSHA to consume that storage and create a file system. Support for VMDK files is based on the multi-writer option described in this VMware article: By default, one VMDK file can only be mounted by one VM at a time. By following the steps in the VMware article, simultaneous write protection provided by VMFS is disabled using the multi-writer flag. When choosing this configuration, users should be aware of the following limitations and advantages.


The advantage is that server vMotion is supported.

The lack of SCSI-3 PR IO fencing support requires the usage of at least three Coordination Point servers, to provide non-SCSI-3 fencing protection. In case of a split brain situation, CP servers will be used to determine what part of the sub-cluster will continue providing service. Once the multi-writer flag is enabled on a VMDK file, any VM will be able to mount it and write, so special care in the provisioning phase needs to be taken.

Note that if the number of SFCFSHA nodes is greater than eight, several nodes will have to run in the same ESXi server, based on the limitation that a maximum of eight ESXi servers can share the same VMDK file. For example, if you are running at the SFCFSHA maximum of 64 nodes, those 64 VMs would share the same VMDK file, but you could only use eight ESXi servers to host the cluster.

These are the steps that need to be taken when configuring VMDKs as shared backed storage and that will be presented in the next sections:


Storage deployment task

Deployment steps

Enabling Disk UUID on virtual machines (VMs)

See Enabling disk UUID on virtual machines.

Installing Symantec Array Support Library (ASL) for VMDK on cluster nodes

See Installing Symantec Array Support Library (ASL) for VMDK on cluster nodes.

Excluding the boot disk from the Volume Manager configuration

See Excluding the boot disk from the Volume Manager configuration.

Creating the VMDK files

See Excluding the boot disk from the Volume Manager configuration.

Mapping VMDKs to each virtual machine

See Mapping the VMDKs to each virtual machine (VM).

Enabling the multi-write flag

See Enabling the multi-write flag.

Getting consistent names across nodes

See Getting consistent names across nodes.

Creating a Cluster File System

See Creating a clustered file system.