the least entitlement / shares ratio ???

[KevinLee]

Hello All,,

I try to set Reservation / Limit / Share values to VMs.

And find out a document 200704231539110.TSX2007-CpuSched-Handout.doc by googling.

Article: http://www.vmware-tsx.com/download.php?asset_id=36

Document introduces 3 rules.

1. A VM or resource pool is always entitled to its reservation

2. A CPU entitlement can never exceed the limit, even if there are unutilized CPU entitlements available.

3. Entitlements are granted preferentially to the resource pools and VMs which have the least entitlement / shares ratio. This is because the VMs or resource pools with more shares are entitled to more CPU resources. In other words, we try to equalize the entitlement / shares ratio of all the VMs. This handing out of entitlements to VMs and resource pools is done in an iterative manner, where CPU entitlements are handled 1 MHz at a time, to the most deserving VM or resource pool.

Rule 1 & 2 is easy to understand. But I don't fully understand Rule 3.

Is there anybody who can describe principle of Rule 3 ?

and also

Find X, Y which minimize | X / 200 – Y / 600|

Thanks in advance.

[KevinLee]

I tested CPU entitlement as document described.

Admin = 4000 MHz

Alice Pool = \[1500-U], S=200

Bob Pool = \[1000-U], S=600

in Alice Pool

VM1 = \[0-500], S=600

VM2 = \[750-U], S=200

in Bob Pool

VM3 = \[500-1000], S=400

VM4 = \[500-U], S=200

The test results are different from Document calculation.

Document calculation =

Alice = 1500

Bob = 2500

VM1 = 500

VM2 = 1000

VM3 = 1000

VM4 = 1500

Test results =

Alice = 1720

Bob = 2250

VM1 = 500

VM2 = 1220

VM3 = 1000

VM4 = 1250

Please explain these different results.

[oreeh]

Read the following thread http://www.vmware.com/community/thread.jspa?threadID=73411