Add Data Disks to SoftNAS VM

 

Adding storage to SoftNAS involves adding virtual hard disks (VMDK's on VMware/Hyper-V, EBS volumes on AWS EC2) to the SoftNAS VM.  The first step is to decide how you want to connect the drives, then associate the disks' storage with the SoftNAS VM as virtual disks.

 

For example, let's say you have ten 300 GB 15K SAS drives attached to your VMware host.  There are a several ways to incorporate these drives into SoftNAS.

 

Option 1 - Add Hardware RAID Datastore and Virtual Disks (VMware and Hyper-V)

 

In this case, you treat the 15K SAS drives just like any other RAID array you would create for a VMware host, using the vendor-supplied software that came with your disk controller to configure and establish a RAID array. 

 

For example, let's assume you chose to configure ten disks as RAID 6 (dual parity), plus one hot spare.  This leaves you with seven data drives in the array.

 

In VMware, the disk array will appear as a single datastore to VMware.  You will add this storage in the usual way, using Add Storage menu in vCenter / vSphere client to create a datastore from the array.  We'll call this datastore, hwraid1.

 

      hwraid1 array ---  7 data disks

                                ---  2 parity disks

                                ---  1 spare disk

 

       datastore1 - hwraid1 array

 

Then, in VM Settings for SoftNAS, you can allocate one or more VMDK's to the SoftNAS VM in this new datastore hwraid1.  If you're running ESXi 5.x or later, you can allocate one large VMDK so the entire datastore is allocated to SoftNAS as a single virtual disk.  If you're using ESXI 4.x, then datastores are limited to 2 TB maximum, so you can allocate as many virtual disks as needed to add this storage to the SoftNAS VM.

 

Thin-provisioned VMDK's are faster to back up later (using a VMware backup tool), since you only back up the storage that's actually used.  Thick-provisioned VMDK's are slightly faster and may be preferred for higher-performance applications.

 

Hardware RAID generally provides the highest-performance, since the disk controller is optimized for managing the RAID operations and all RAID overhead is handled in hardware, and LED indicators and other hot-swap functionality is handled by the vendor sofware (including failure notification and remediation).  When a disk fails, the hardware is optimized for rebuilding the array with the replaced disk (whether hot-swapped or manually swapped).

 

If you have a large number of disks (e.g., 48 or more), using hardware RAID with an optimal number of physical drives per RAID array provides significant performance advantages vs. very large single arrays (and hardware RAID rebuilds will be much faster this way).

 

After creating the RAID array, follow the usual steps in VMware vSphere / vCenter to add the array as a storage device and create a datastore.  This datastore will then be used to create one or more VMDK's to be used as SoftNAS data disks.

 

 

Option 2 - Add Disks Individually to VMware and use Software RAID

 

In this case, you will add each 15K SAS drive to the VMware host directly.  You will have the option in VMware to either format each disk and create a corresponding datastore per disk device, or use the disks directly as raw disks.  Whichever approach you choose to take, the goal is to make the disks available to the SoftNAS VM on a one-to-one basis; i.e., each disk's storage is mapped to the SoftNAS VM as a separate VMDK.

 

Disks mapped to datastores:

 

      disk 1 ---   datastore1

       disk 2 ---   datastore2

       . . .

       disk 10 --- datastore10

 

 

Disks mapped as raw devices:

 

       disk 1 ---   rawdisk1

       disk 2 ---   rawdisk2

       . . .

       disk 10 --- rawdisk10

 

The key at this stage if to map the disk drives to VMDK's and attach to SoftNAS.

 

SoftNAS will map disks into one or more storage pools, and software RAID will be applied to each disk group.  Software RAID provides may provide increased flexibility of administration, enabling the SoftNAS administrator to more quickly and easily add, expand and manage RAID groups from the SoftNAS StorageCenter interface.  Of course, software RAID is handled by the CPU, which adds overhead to the VMware system and SoftNAS VM.  In the event of a drive failure, the rebuild process also must take place in software, which is typically much slower than when handled by a hardware RAID controller.

 

 

Add Elastic Block Storage (EBS) to SoftNAS Instance (AWS EC2)

 

On Amazon EC2, you attach EBS volumes to SoftNAS as block storage.  Then, within SoftNAS Disk Devices configuration panel, those devices are partitioned in preparation for use.

 

Be sure to make note of the EBS volume naming recommendations.

 

 

Amazon S3 Cloud Disks for Cloud Storage (All Platforms)

 

You can also use S3 Cloud Disks to manage up to 4 petabytes of Amazon S3 cloud storage per device, with no additional local storage required.  Learn more.

 

Artisan OBS Cloud Discs

 

You can use Artisan OBS Cloud Discs to use object based storage (OBS) and create cloud disks.  You can leverage SoftNAS to manage this storage by creating Artisan data disks (buckets) and storage pools.

 

 

Add VMDK's to SoftNAS VM (VMware/HyperV)

 

Once you have chosen between options 1 and 2 above, proceed and connect the disk drives to the SoftNAS VM as data disk VMDK's.

 

Inside of Linux (where SoftNAS executes), each attached VMDK will appear as a block disk device.  The devices will be named /dev/sdb, /dev/sdc, etc. - one Linux block device per data disk VMDK.  These block devices appear as unpartitioned, raw disk devices inside of Linux, so the next step will be to partition the block devices with a GPT partition.

 

After adding the VMDK's to the SoftNAS VM and partitioning the disks, they become available to assign to storage pools.

 

Note:  After you have added VMDK's to a SoftNAS VM, do not remove the virtual disks attached to the VM after they are placed into production, as the next time you reboot it will cause the drives to be renumbered, requiring an "Import" of the storage pools after the reboot (if you must remove VMDK's for any reason, be aware of the implications).