You would not need to worry about that even if you add/remove LUNs.
Powerpath maintains a consistent "Logical device ID" across nodes. Even
if your nodes scans the same LUN as say for example empowerc on node1
and emcpowerd on node2, thier Logical device ID will be the same. Hope
that helps.<br>
<br>
Raj<br><br><div><span class="gmail_quote">On 8/31/05, <b class="gmail_sendername">Wu, Hai</b> <<a href="mailto:hxwu@tribune.com">hxwu@tribune.com</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Raj,<br>I
am using PowerPath 4.3.2/RHEL ES3U4/OCFSv1/CX700. For the same node,
are you saying I don't need to worry about adding/removing LUNs? I
thought the device number would change, say from emcpowerd to
emcpowerc, if we were to remove emcpowera.<br><br>Thanks,<br>Hai<br><br>-----Original Message-----<br>From: Raj [mailto:<a href="mailto:sanstorage@gmail.com">sanstorage@gmail.com</a>]<br>Sent: Wed 8/31/2005 10:48 PM<br>
To: Wu, Hai<br>Cc: Joel Becker; <a href="mailto:ocfs-users@oss.oracle.com">ocfs-users@oss.oracle.com</a><br>Subject: Re: [Ocfs-users] problem with OCFS label<br>Wu,<br><br>OCFS
label does not work with EMC powerdevices. EMC powerdevices uses a
logical ID number which knows the path to the correct LUNs on the
backend. Compare those on each nodes and they will be the same. Do a
powermt display dev=all and you find that long number which will be the
same across nodes. If you need a consistent look and feel across all
the nodes you will need to copy the Powerpath config file across nodes
and then reboot. What version of PowerPath are you using?<br><br>Hope that helps.<br><br>Raj<br><br><br>On 8/31/05, Wu, Hai < <a href="mailto:hxwu@tribune.com">hxwu@tribune.com</a>> wrote:<br><br>Thanks
Joel. If I can't use OCFS label, then how can I make sure I am still
mounting the same emcpower device if we need to add/remove powerpath
LUNs? I know that devlabel would not work in this case. (And IBM this
its own way of dealing with this problem, not sure about EMC in this
case).<br><br>Thanks,<br>Hai<br><br>-----Original Message-----<br>From: Joel Becker [mailto: <a href="mailto:Joel.Becker@oracle.com">Joel.Becker@oracle.com</a>]<br>Sent: Wed 8/31/2005 8:28 PM<br>To: Wu, Hai<br>Cc:
<a href="mailto:ocfs-users@oss.oracle.com">ocfs-users@oss.oracle.com</a><br>Subject: Re: [Ocfs-users] problem with OCFS label<br>On Wed, Aug 31, 2005 at 06:42:20PM -0500, Wu, Hai wrote:<br>> But when I tried to mount this ocfs filesystem by label, it gave me the following error.
<br>> # mount -L data13 /oradata/data13<br>> mount: the label data13 occurs on both /dev/emcpowerp1 and /dev/sdad1 - not mounted<br><br> This isn't a bug, this is a common problem with multipath.<br>mount(8) does not know that /dev/emcpowerp1 and /dev/sdad1 are the same
<br>drive. So it cannot decide which to use. You must mount by device name<br>in this case.<br><br>Joel<br><br>--<br><br>"Gone to plant a weeping willow<br>On the bank's green edge it will roll, roll, roll.<br>Sing a lulaby beside the waters.
<br>Lovers come and go, the river roll, roll, rolls."<br><br>Joel Becker<br>Senior Member of Technical Staff<br>Oracle<br>E-mail: <a href="mailto:joel.becker@oracle.com">joel.becker@oracle.com</a><br>Phone: (650) 506-8127
<br><br><br>_______________________________________________<br>Ocfs-users mailing list<br><a href="mailto:Ocfs-users@oss.oracle.com">Ocfs-users@oss.oracle.com</a><br> <<a href="http://oss.oracle.com/mailman/listinfo/ocfs-users">
http://oss.oracle.com/mailman/listinfo/ocfs-users</a>> <a href="http://oss.oracle.com/mailman/listinfo/ocfs-users">http://oss.oracle.com/mailman/listinfo/ocfs-users</a><br><br><br><br><br><br></blockquote></div><br>