powerpath upgrade issue

Question

Hi I am running  some DBs on a  Solaris Sparc server with PowerPath .The DBs are on  raw LUNs from a Clariion array . I  had to do a upgrade of Powerpath from 5.3 to 5.5 .I followed the normal steps  Unistall the earlier version  and Install the new version But after installing 5.5 the emcpower pseudo devices  mapping  got changed. i.e the LUN with pseudo device name emcpower1a earlier  is now showing emcpower2a .This has happened to all the LUNs  Needless to say the databases and the filesystems on the LUNs  have become  inaccessible I tried to  copy the original emcp.conf file but it gets regenerated with  each reboot and  changes  the contents I   tried to manually change the  pseudo device names to their correct device files  using emcpadm renamepseudo commands  after which  the filesystems became accessible but these changes do not persist  over the reboot How can I now restore the  original  mappings  For the time being I have now started the servers with the alternate boot  environment Is this a expected behaviour  Is there any  configuration backup  should be taken before  installing the new PP version  which can then be imported back Appreciate any insights  and help regarding this

daverush · Answer

rkk1969, You'll need to issue a 'powermt save' for your renamed mapping to persist past a reboot. To answer your questions: Is this a expected behaviour It is. Without a saved configuration, PowerPath numbers devices in the order they are scanned. How can I now restore the  original  mappings Rename the LUNs again, and a 'powermt save' will make them permanent. Is there any  configuration backup  should be taken before  installing the new PP version  which can then be imported back There is. Page 119 of https://support.emc.com/docu10576_PowerPath-Family-5.5-for-Solaris-and-5.2-for-HP-UX-CLI-and-System-Messages-Reference.p… lists the emcpadm command syntax to export and import mappings. Export the mapping before upgrading/reinstalling PowerPath and import it after.  Remember to 'powermt save' afterward.

sgtserge1 · Answer

Hi rkk1969,

after configuring the right pseudodevices have you tried the command:

/etc/powermt save

Also there's a command to export the exsisting pseudodevice config:

/opt/EMCpower/bin/emcpadm export_mappings -f pseudodevices.cfg

This save the conf to file "pseudodevices.conf" that can be used with the "import" switch.

hope this helps.

Sergio

PowerPath

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