I have a server running RHEL 5.5 with EMC PowerPath installed. Due to the security requirement, I had to upgrade the kernel to a newer version. Unfortunately, I was not aware of the impact of the upgrade on EMC PowerPath. After the upgrade, the server cannot load the PowerPath kernel modules anymore.

So, I downgraded back to the original kernel. Still the kernel modules refused to load.

I tried up load the modules manually, but get the following error.

[root@cvoapd05 EMCpower.LINUX-]# modprobe emcp
FATAL: Error inserting emcp (/lib/modules/2.6.18-194.32.1.el5/powerpath/emcp.ko): Device or resource busy

The .ko files are still in the path "/lib/modules/2.6.18-194.32.1.el5/powerpath", and the file sizes and dates are unchanged.

Is there anyway I can recover from this problem?


# grub.conf generated by anaconda
# Note that you do not have to rerun grub after making changes to this file
# NOTICE:  You have a /boot partition.  This means that
#          all kernel and initrd paths are relative to /boot/, eg.
#          root (hd0,0)
#          kernel /vmlinuz-version ro root=/dev/cciss/c0d0p8
#          initrd /initrd-version.img
# default=0 # commented out by Proliant HBA install script
title Red Hat Enterprise Linux Server (2.6.18-194.32.1.el5)
        root (hd0,0)
        kernel /vmlinuz-2.6.18-194.32.1.el5 ro root=LABEL=/ rhgb quiet crashkernel=1024M@16M
        initrd /initrd-2.6.18-194.32.1.el5.img

title Red Hat Enterprise Linux Server (2.6.18-194.el5)
        root (hd0,0)
        kernel /vmlinuz-2.6.18-194.el5 ro root=LABEL=/ rhgb quiet crashkernel=1024M@16M
        initrd /initrd-2.6.18-194.el5.img

# This entry (no. 1) added by Proliant HBA install script
# in package cpq_cciss-3.6.26-5.rhel5
title HP-2.6.18-194.el5
        root (hd0,0)
        kernel /vmlinuz-2.6.18-194.el5 ro root=LABEL=/ rhgb quiet crashkernel=1024M@16M
        initrd /HP-initrd-2.6.18-194.el5.img
  • Post the output of uname -a and the contents of your /etc/grub.conf – dmourati May 26 '11 at 4:54
  • Uname as follows: [root@cvoapd05 ~]# uname -a Linux cvoapd05 2.6.18-194.32.1.el5 #1 SMP Mon Dec 20 10:52:42 EST 2010 x86_64 x86_64 x86_64 GNU/Linux Grub.conf is added to the question above. – kjloh May 26 '11 at 6:19
  • Take a look at lsmod | grep emcp – quanta May 28 '11 at 17:36
  • Does anything show up in dmesg when you try loading the module? That's typically where load-time errors show up. – duskwuff -inactive- May 29 '11 at 0:22

There is probably another driver attached to a device that the powerpath driver is trying to attach to. Check to see if there are any other multipath drivers loaded, lsmod | grep path should be sufficient. In fact, simply providing the output of lsmod should help us determine what is causing this issue.

| improve this answer | |

Use the native multipath-daemon instead of powerpath.

| improve this answer | |
  • Do you have any evidence that one is better than the other? – Mark Wagner Aug 5 '11 at 18:38
  • 1
    It is alwas bad to have vendor specific special changes in your os - you currently experience that. I found the same to be true with attaching linux to a HP-EVA-SAN (with SLES10 I need a special HBA-driver from HP, needs to be recompiled at every kernel-update). Take a look at multipathd - there is almost certainly emc-powerpath-support already built in. – Nils Aug 5 '11 at 19:23
  • With Linux native multipath i never found this problem – c4f4t0r Sep 19 '13 at 17:44
  • @Mark see above comments. Give it a try... – Nils Sep 19 '13 at 21:18

/etc/rc.d/PowerPath has logic in it to determine if a different kernel has been loaded and if so update its configuration, which involves more than copying emcp.ko.

Try manually running /etc/rc.d/PowerPath start to either fix the problem or get more information on what the problem is.

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.