This post is more than 5 years old
59 Posts
1
8952
HOW TO CHECK MULTIPATHING IS WORKING OR NOT
Hi friends,
Recently we have a director(7d processor only faulted,only used for srdf) failure in DMX 4 at DR site.Before director replacement time
we took down time from all single path servers assosciated with that director.But we did not take any down time from dual path servers.But
while replacement time,it is observed that dual path server also faced problem in accessing lun.Later
we observed power path licensing is not done properly,so it did not work.what I want to know is,is there any method for knowing powerpath
or any multipathing software working properly or not?,other than removing cables manually to disable redundant paths and testinng it.
anoopcr
148 Posts
1
April 12th, 2012 02:00
Hi Srik,
"Unlic" means unlicensed. The path is not licensed. If the path is not licensed there wont be any communication through this path.So when you replace the director 7,all the 4 processor become inaccessible. Here during that time there was no active path to the luns(10bA in unlicensed mode )
During initial PowerPath installation, the license key is added after a host reboot, the PowerPath policy by default is set to Basic Failover. After adding the license key the PowerPath policy must be manually changed to ClarOpt for CLARiiON arrays and SymmOpt for Symmetrix storage systems in order to maximize PowerPath's potential.
To Fix this unlicensed paths in powerPath issue you can follow below work around mentioned in primus solution emc135527
To resolve the issue with LUN from Symmetrix :
1. powermt check_registration (Make sure the license shows with full capabilities.)
2. powermt set policy=so dev=all (Set the Policy to SymmOpt.)
3. powermt display dev=all (Make sure all device paths are now licensed.)
4. powermt save (Save configuration.)
To resolve the issue with LUN from CLARiiON :
1. powermt check_registration (Make sure the license shows with full capabilities.)
2. powermt set policy=co dev=all (Set the Policy to ClarOpt.)
3. powermt display dev=all (Make sure all device paths are now licensed.)
4. powermt save (Save configuration.)
To resolve the issue with LUN from Other Storage Systems :
1. powermt check_registration (Make sure the license shows with full capabilities.)
2. powermt set policy=ad dev=all (Set the correct policy.)
3. powermt display dev=all (Make sure all device paths are now licensed.)
4. powermt save (Save configuration.)
Note:
UNIX Servers: If the license key is not installed, use the emcpreg –install command.
Windows Servers: If the license key is not installed, use the emclictool.exe via the Programs Menu.
dynamox
1 Rookie
1 Rookie
•
20.4K Posts
1
April 11th, 2012 21:00
that can only be checked from the host side, "powermt display dev=all". There should be multipath paths, all alive, correct policy ..etc.
Srik1920
59 Posts
0
April 11th, 2012 23:00
Hi dynamox,
can you explain the below screenshot,it is output of "powermt dispaly dev=all".for one path mode it is showing "unlic",what does it mean.
sauravrohilla
859 Posts
1
April 12th, 2012 05:00
Thanks Anoop for sharing this useful information.
Srik, unlic means that you can only opt for BasicFailover policy in PP (simply menas unlicensed). If the path 7ba (from your snapshot) goes down then it PP will not route the IOs to unlic path.
regards,
Saurabh
Srik1920
59 Posts
0
April 12th, 2012 05:00
Hi Anoop,
Thanks for your reply.It is very useful to me.