LUN to VM and Host Ratio
Posted on 2013-02-06
We are currently planning to virtualize our physical environment. We have purchased a dell equallogic PS4100X (iscsi) with 24 x 600GB SAS disks which will be configured in a RAID 50 Configuration with two hot spares. Total usable storage will be approx 13 TB.
We will be running Vsphere 5.1 essentials plus across two Physical Vmware hosts.
15 physical servers will be virtualized and another 5 servers will be deployed over the next 3 months.
Our current data storage usage is 2TB and approx storage to be used up after virtualization will be approx 3 TB.
We are planning to dedicate a LUN for disk backups (before spinning off to tape)
Initally we were thinking of have two luns and two datastores. One for production servers and the other as the backup storage area However after some research we have some concerns if this will impact performance.
After reading a best practice white paper from vmware it was recommended to have a "consolidation with some level of isolation"
Our servers are not very resource hungry we have a typical windows environment with file servers, DCs, SQL 2005, 2 x citrix servers with approx 60 citrix users and Exchange.
As a rough guideline how many LUNS per VM should we have? What whould we be considering?
Is there an issue with two vm hosts accessing the same datastore/LUN ?
I think we should carve out LUNs as required so maybe we should start with 2 or 3 LUNs and spread our servers across there then create additional LUNs as required.
any advice would be appreciated.