Hello,
I first size my VMs, then size the LUN based on that.... The formula is:
Size of VMDKs * 2 (to include possible snapshots) + 15mbs (sundry metadata files) + sizeof Allocated Memory + 4GBs (sundry log files) = Size of VM
Size of VM * # of VMs * 1.2 = Space required for LUN with a 20% buffer.
You never want to fill a LUN past 90% and 80% is a much better number. If the VMFS is too full things stop working.
If you have a LUN size already in mind you can determine how many VMs will fit using:
Size of LUN * 0.8 / Size of VMDKS = # of VMs
Yes this sounds like a bit of empty space per LUN but it is a conservative approach for a base #.
Best regards,
Edward L. Haletky
VMware Communities User Moderator
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Author of the book 'VMWare ESX Server in the Enterprise: Planning and Securing Virtualization Servers', Copyright 2008 Pearson Education.
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