Max emcpower devices on Linux 4 server

Question

I am running a Linux server with the following;

PowerPath Version 5.1.0 (build 194)
RedHat AS 4.0 Kernel 2.6.9-67.0.1.ELhugemem
On a DMX-3
Two Emulex LP-10000's

I currently have 17 devices assigned to this server which go up to /dev/emcpowerq. I need to add more capacity this server, but before I do I wanted to know if there is a maximum number of power devices this server configuration can handle?

Conor · Answer

Hi PMac - welcome to the forum!

The limit of supported (by EMC) SCSI devices on Linux hosts is 1024.. Every path to a LUN is counted as a SCSI device, so if you have 4 paths to each LUN then the maximum number of emcpower devices is 1024/4 = 256.

PowerPath supports up to 32 paths to each device.

Let me know if this answers your question.

Conor

pmcmurray · Answer

Conor,Thanks for your reply. My next question is if I assign more devices to this server and I reach device emcpowerz, what will be the next pseudo name that gets assigned?

pmcmurray · Answer

I ended up having to add more devices to this same server. After I added emcpowerz, the next device had the pseudo name of emcpoweraa.

PowerPath

Max emcpower devices on Linux 4 server

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