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Users cannot read on devices until root do it

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Gaël LEPETIT
Occasional Advisor

Users cannot read on devices until root do it

Hi,

On a HP Blade 870c with HP-UX 11i v3 and the very last version of Powerpath 5.1 SP1 (imposed upon me), a strange effect appear after each reboot.
A simple user is unable to read (via dd) on san disks. The error returned is "permission denied".

$ dd if=/dev/rdsk/c5t0d0 of=/dev/null bs=1k count=1
/dev/rdsk/c5t0d0: Permission denied
dd: cannot open /dev/rdsk/c5t0d0

Of course, all users have the right to read on theses devices.

$ ls -ld /dev/rdsk
drwxr-xr-x 2 bin bin 8192 Feb 12 11:04 /dev/rdsk
$ ls -l /dev/rdsk/c5t0d0
crw-r--r-- 1 bin sys 188 0x050000 Feb 12 10:42 /dev/rdsk/c5t0d0


If root read on the device...
# dd if=/dev/rdsk/c5t0d0 of=/dev/null bs=1k count=1
1+0 records in
1+0 records out

Now normal users can access the data
$ dd if=/dev/rdsk/c5t0d0 of=/dev/null bs=1k count=1
1+0 records in
1+0 records out

My intuition aim at Powerpath. But how can I be sure ?


Anyone got an idea ?
http://quelquesbrassesdanslesysteme.blogspot.com/
8 REPLIES
Laurent Menase
Honored Contributor

Re: Users cannot read on devices until root do it

contact hp support
lizhen_1
Occasional Visitor

Re: Users cannot read on devices until root do it

Hi,we have got the same problem.
Can you tell me how you solve the problem?
presario_1
Occasional Visitor

Re: Users cannot read on devices until root do it

hello Gaël LEPETIT :

i have same problem with you. what have you done for this? please help me .thanks a lot.
Gaël LEPETIT
Occasional Advisor

Re: Users cannot read on devices until root do it

We have opened a case at EMC support but the tech weren't able to reproduce the bug.
And our HP support contract is very limited.

So I was thinking the problem only happened to our server until today.

We are using a stopgap measure : an "ioscan" launched in the startup scripts.

If you find a "real" solution, keep me in touch.

http://quelquesbrassesdanslesysteme.blogspot.com/
lizhen_1
Occasional Visitor

Re: Users cannot read on devices until root do it

What is your os patch bundle level?
our hp-ux 11i v3 level is:
Sep '08 (11.31 Standard Patch Bundles).

Do you want to upgrade to
Mar '09 (11.31 Standard Patch Bundles)
lizhen_1
Occasional Visitor
Solution

Re: Users cannot read on devices until root do it

EMC confirmed that it is a powerpath bug. They will fix the bug in next version (may by sp2).You can view the KB primus218370 from powerlink.

PowerPath 5.1 SP1
HP-UX 11.31
Product: Oracle ASM 10g 64-bit


After Powerpath upgrade to 5.1 SP1, Oracle ASM & CRS automatic start failed on HP-UX 11.31


OCR initialization failed accessing OCR device: PROC-26: Error while accessing the physical storage Operat
ing System error [Permission denied] [13]


PowerPath is upgraded from 5.1 to 5.1 SP1


PowerPath 5.1 SP1 has been enhanced w.r.t handling iSCSI devices when compared to earlier versions of PowerPath.
As part of the new feature, handling of opening the devices underwent few changes in PP 5.1 SP1. PowerPath issues pass-through
ioctl while opening the device. PowerPath will check the result returned from the pass-through ioctl. As per HPUX semantics,
Pass-through ioctl requires super-user privilege access. So, if any application which is running in non-root privilege, if
it tries to open the device, the open operation will fail with æ ermission denied ?error message.
At the customer environment , Oracle daemon ( which is running as non-root ) is trying to open the device, hence there is æ ermission Denied ?error.


Work Around Recommendations:
----------------------------
- Execute "syminq" or "inq" commands during boot immediately after the PowerPath services starts.
Why we recommend the above solution as a work around?
-----------------------------------------------------------
- "syminq" or "inq" gets executed with root user privilages if they are run during boot operation. These operations will leave the devices
accessed and opened. There-by any subsequent device open attempt either in root or non-root doesnæ ° go through the pass-through ioctl
way as they are already opened. This allows the Oracle deamon to auto-start in non-root privileges.


The Oracle ASM & CRS starts automaticly only when syminq or inq is run on the system?!?


OPT 313586
Gaël LEPETIT
Occasional Advisor

Re: Users cannot read on devices until root do it

In fine, Powerpath was the problem.

Let's see the last releases notes :

313586
After upgrading from PowerPath 5.1 to PowerPath 5.1 SP 1 on a HP-UX 11.31 system, starting
Oracle ASM & CRS in an automatic mode leads to failure.The error message from the Oracle is:
"OCR initialization failed accessing OCR device: PROC-26: Error while accessing the physical
storage Operating System error [Permission denied] [13]".

Thanks Lizhen
http://quelquesbrassesdanslesysteme.blogspot.com/
Gaël LEPETIT
Occasional Advisor

Re: Users cannot read on devices until root do it

Closing thread.
http://quelquesbrassesdanslesysteme.blogspot.com/