VMware Storage I/O Control:-
Requirements of VMware Storage I/O Control:-
- vSphere 4.1 or later
- Only Fiber channel and ISCSI is supported and not NFS and RDM
- Datastores must be supported by single vCenter server
- Multiple extend datastores are not supported for SIOC
How VMware Storage I/O Control Works :-
Graphic thanks to VMware.com
The above diagram describes the difference between without & with Storage IO Control. In the left side of diagram, There are 2 ESX servers which contains a shared LUN without configured with the storage I/O control. 3 Virtual machines are running in total of 2 hosts. In the ESX server 1, 2 VMs (VM A with 1500 shares & VM B with 500 Shares) and in ESX server 2, 1 VM (VM C with 500 shares). If you noticed the VM B & VM C both are configured with the share value of 500 but VM B is utilizing 12% in the storage array Queue but VM C with the same share value of 500 utilizing 50 % of Storage Array Queue. This is imbalanced and we don’t have any control over these.
In Right Side of Diagram, There are 2 ESX servers which contains a shared LUN configured with the storage I/O control. 3 Virtual machines are running in total of 2 hosts. In the ESX server 1, 2 VMs (VM A with 1500 shares & VM B with 500 Shares) and in ESX server 2, 1 VM (VM C with 500 shares). If you noticed both the VM B & VM C are configured with the share value of 500 and utilizing the 20% in the storage array Queue unlike the above imbalanced approach.each VM is given an appropriate allocation of disk resources in the storage array.
How to enable SIOC in datastore
Check the Storage I/O Control Enabled check box to enable the Storage I/O Control for that particular Datastore.
If you want to edit the Congestion Threshold, Click advanced and enter the Value like 10 ms. Default value is 30 ms
Configure Shares in Virtual Machines in the above datastore:
To configure the shares and IOPs,Right-click on a Virtual Machine and edit settings.
Goto Resources Tab and select Disk. Select the share type (Low, Normal, High & Custom) which you want to configure for the Virtual machine and click on OK.
I hope this is informative for you. Thanks for Reading!!!. Be social and share it in social media like Facebook, Google+ and twitter, if you feel worth sharing it.