VMware Getting Started - Configuring VM Settings

Required Settings

After installing the OVF to create the SoftNAS Virtual Storage Appliance VM, configure the VM settings in accordance with best practices and network needs. The boot disk (Hard Disk 1) should be set to 30 GB, thin-provisioned.

For a quick benchmarking resource configuration, use 4 vCPUs and 4 to 8 GB of RAM. Configure storage and run benchmarking tools to observe resource utilization in the SoftNAS StorageCenter Dashboard charts and vSphere performance charts.

RAM Note: The operating system and SoftNAS consume up to 1 GB of RAM, using most of the remaining RAM for cache memory and metadata. The more RAM assigned to the VM, the better read cache performance will be, as SoftNAS will keep as much data in RAM cache as possible. Consider this resource allocation for deduplication: at least 1 GB of RAM per terabyte of deduplicated storage, to keep the deduplication tables in memory (or supplement the RAM cache with a read cache device).

Optional Settings

Paravirtual SCSI Disk Controller Support

For maximum throughput and IOPS on VMware, choose the Paravirtual SCSI Controller for the SoftNAS VM (instead of using the default LSI Logic Parallel SCSI controller). 

VM Snapshot Mode

Before applying software updates to SoftNAS after it is in production, and to support online backups in popular backup programs, VM snapshots are useful as part of the backup and recovery process. Depending on the plan to manage backups of VM data, choose which mode snapshots will operate in.

  • Independent Mode - to enable smaller VM snapshots, configure the boot disk, Hard Disk 1, in the "Independent" mode. This causes VM snapshots to apply only to this first hard disk by default (and not include all added data disks, which could be prohibitively large). The advantage of using Independent mode is VM snapshots will be faster and smaller.
  • Dependent Mode - by default, VM snapshots include all hard disks attached to the VM. When used with SoftNAS and a VM backup process, this setting causes all SoftNAS VM disks to be backed up together as a set. This results in much larger backup sets, but may be preferable as a means of achieving additional protection and recoverability in the event of a disaster or need to restore the entire storage system to a different computer or location. If there are only a few terabytes to back up, this may be the prudent choice.

Network Adapter

On a typical 1 gigabit network, the default E1000 network adapter is sufficient; however, for a 10 gigabit or higher-performance network card, the VMXNET 3 network adapter should be used for best results and higher throughput. Note that installation of the VMXNET 3 requires installation of the proper VMware Tools in the guest operating system (in this case, CentOS 64-bit Linux).

Memory / CPU Hot Plug

It is recommended to allow CPU Hot Plug and disable Memory Hot Add, which will make it more convenient to add CPU later to use a lot of data compression or other features that consume additional CPU. Linux seems to do fine when additional CPU are added at run-time. 

Note: Add memory with the system powered down and disable hot add of memory at run time.