nicholas1982
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Fibre Channel - Paths to a LUN

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Hi, Could someone kindly confirm this from the vSphere Config Max document.

6290_6290.jpg

Is this the maximum paths to a single LUN from an ESX4 host?

If that the case a single ESX host can see max 256 LUNS

256 LUNS x 16 paths = 4096 paths, however it also state max paths per host is 1024. So if I understand correctly "Total paths on a host"

would be the limiting factor, and we can say based on the amount of paths per host that would limit the amount of LUNS it could see.

Nicholas VCP6
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AndreTheGiant
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Usually (in switched fabric with 2 HBA for each host) the number of path for each LUN is 4.

So 256 x 4 = 1024.

You can use more HBA to have more path, but in this case I think that the number of total LUN (for each hosts) will be smaller.

Andre

Andre | http://about.me/amauro | http://vinfrastructure.it/ | @Andrea_Mauro

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AndreTheGiant
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Usually (in switched fabric with 2 HBA for each host) the number of path for each LUN is 4.

So 256 x 4 = 1024.

You can use more HBA to have more path, but in this case I think that the number of total LUN (for each hosts) will be smaller.

Andre

Andre | http://about.me/amauro | http://vinfrastructure.it/ | @Andrea_Mauro

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nicholas1982
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Thanks Andre,

I'm just going through this document to study for the VCP4 exam, are you able to explain the next two item's

LUNs concurrently opened by all virtual machines = 256

And

LUN ID = 255

Thanks Nicholas

Nicholas VCP6
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AndreTheGiant
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I also are study for the VCP4 exam Smiley Happy

LUN ID start from ID 0, so the max id is 255.

Andre

Andre | http://about.me/amauro | http://vinfrastructure.it/ | @Andrea_Mauro
nicholas1982
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Thank's Andre,

Now I just need to find out what LUNs concurrently opened by all virtual machines means exactly.

Do you mind me asking what docs you are studying for the VCP4? I found this link quite usful. most link to VMware PDFs

http://www.simonlong.co.uk/blog/vcp-vsphere-upgrade-study-notes/

Thanks

Nicholas

Nicholas VCP6
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AndreTheGiant
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Do you mind me asking what docs you are studying for the VCP4?

There are also some other links in VCP Community (http://communities.vmware.com/community/vmtn/certedu/certification/vcp)

Andre

Andre | http://about.me/amauro | http://vinfrastructure.it/ | @Andrea_Mauro
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