Re: ASM bug?
- From: Andrew Kerber <andrew.kerber@xxxxxxxxx>
- To: Maureen English <maureen.english@xxxxxxxxxx>
- Date: Thu, 2 Oct 2014 17:15:51 -0500
It's been a while since I did this, but as I recall there is some guidance
about the ASM disk string and exclude and include options with multi path. Did
you verify all that?
Sent from my iPad
> On Oct 2, 2014, at 11:55 AM, Maureen English <maureen.english@xxxxxxxxxx>
> wrote:
>
> Stefan, Andew;
>
> Yes, we are using ASMLIB.
>
> - Maureen
>
>> On 10/2/2014 7:56 AM, Andrew Kerber wrote:
>> I am pretty sure the labels she mentions and the disk scanning are the
>> ASMLIB methods
>>
>> Sent from my iPhone
>>
>> On Oct 2, 2014, at 10:26 AM, Stefan Koehler <contact@xxxxxxxx> wrote:
>>
>>> Hi Andrew,
>>> for sure - is she using ASMLIB?
>>>
>>> I may have missed some posting about that, otherwise Maureen may provide
>>> this information in addition later on. However the persistent device naming
>>> (multipath binding) is also needed / recommended with ASMLIB (scan order).
>>> I personally would go for udev anyway :-))
>>>
>>> Best Regards
>>> Stefan Koehler
>>>
>>>> Andrew Kerber <andrew.kerber@xxxxxxxxx> hat am 2. Oktober 2014 um 17:06
>>>> geschrieben:
>>>>
>>>> Sounds like a bug. If she is using ASMLIB, she does not use Udev. The
>>>> two are mutually exclusive.
>>>>
>>>> Sent from my iPhone
>>>>
>>>> On Oct 2, 2014, at 2:53 AM, Stefan Koehler < contact@xxxxxxxx> wrote:
>>>>
>>>>> Hi Maureen,
>>>>> that's no bug. You have to use persistent device naming (multipath
>>>>> binding) by multipathd and udev rules to set the correct device
>>>>> permission / owner.
>>>>>
>>>>> However be aware of the suggested multipath settings by every storage
>>>>> vendor (e.g. fail_if_no_path with NetApp) and ASM. In some cases you are
>>>>> not able to flush the device map due to such suggestions after a path
>>>>> failure, even if the disk is not used by ASM anymore.
>>>>>
>>>>> Best Regards
>>>>> Stefan Koehler
>>>>>
>>>>> Oracle p erformance consultant and researcher
>>>>> http://www.soocs.de
>>>>>
>>>>>> Maureen English < maureen.english@xxxxxxxxxx> hat am 2. Oktober 2014 um
>>>>>> 02:34 geschrieben:
>>>>>>
>>>>>> device-mapper-multipath
>>>>>>
>>>>>>
>>>>>>> On 10/1/2014 4:27 PM, Dimensional DBA wrote:
>>>>>>> What Multipathing SW are you using?
>>>>>>>
>>>>>>> Matthew Parker
>>>>>>> Chief Technologist
>>>>>>> 425-891-7934 (cell)
>>>>>>> Dimensional.dba@xxxxxxxxxxx
>>>>>>> View Matthew Parker's profile on LinkedIn
>>>>>>>
>>>>>>>
>>>>>>> -----Original Message-----
>>>>>>> From: Dimensional DBA [mailto:dimensional.dba@xxxxxxxxxxx]
>>>>>>> Sent: Wednesday, October 01, 2014 5:23 PM
>>>>>>> To: 'maureen.english@xxxxxxxxxx'; 'oracle-l@xxxxxxxxxxxxx'
>>>>>>> Subject: RE: ASM bug?
>>>>>>>
>>>>>>> Did you put the disk id's in the multipath.conf file which hard sets the
>>>>>>> mapping?
>>>>>>>
>>>>>>>
>>>>>>> Matthew Parker
>>>>>>> Chief Technologist
>>>>>>> 425-891-7934 (cell)
>>>>>>> Dimensional.dba@xxxxxxxxxxx
>>>>>>> View Matthew Parker's profile on LinkedIn
>>>>>>>
>>>>>>>
>>>>>>> -----Original Message-----
>>>>>>> From: oracle-l-bounce@xxxxxxxxxxxxx
>>>>>>> [mailto:oracle-l-bounce@xxxxxxxxxxxxx]
>>>>>>> On Behalf Of Maureen English
>>>>>>> Sent: Wednesday, October 01, 2014 4:44 PM
>>>>>>> To: oracle-l@xxxxxxxxxxxxx
>>>>>>> Subject: ASM bug?
>>>>>>>
>>>>>>> We're building a new system and the sysadmin and dba working on it
>>>>>>> discovered a problem.
>>>>>>> This is RHEL5 and Oracle 11.2.0.4 RAC.
>>>>>>>
>>>>>>>> At boot, or when instructed to do so, Oracle ASM scans disks and
>>>>>>>> creates an index of which ASM labels are on which disks, however it
>>>>>>>> does not do anything to tell the kernel that it intends to use the
>>>>>>>> disks
>>>>>>> it has identified. It is not until ASM mounts the disks in a diskgroup
>>>>>>> that
>>>>>>> it marks them as "in use".
>>>>>>>> Until a disk is actually in use (opened), the kernel will happily
>>>>>>>> unmap or re-map dm devices that Oracle ASM has already scanned. Oracle
>>>>>>>> ASM will try to modify the wrong disk if the kernel remaps an unused dm
>>>>>>> device to a different disk before ASM mounts it.
>>>>>>>> When multipath is run with the -F option, it will flush all multipath
>>>>>>>> devices that are not in use. When multipath re-maps the devices, it
>>>>>>>> may assign different device numbers to the disks it flushed. There is
>>>>>>>> no way to tell Oracle ASM to forget about a label it has scanned
>>>>>>>> without deleting the ASM labels off the disk or rebooting the system.
>>>>>>>> It
>>>>>>> is very important not to flush a disk that ASM has already identified.
>>>>>>> Do
>>>>>>> not use multipath -F if there are any unmounted ASM disks presented to
>>>>>>> the
>>>>>>> system.
>>>>>>>
>>>>>>> Is this a known bug, or are there some rules regarding ASM and multipath
>>>>>>> that we missed?
>>>>>>>
>>>>>>> I'm not actually working on this system, but thought it sounds like
>>>>>>> something others would have encountered. I'm still searching through
>>>>>>> Metalink docs....
>>>>>>>
>>>>>>> - Maureen
>>>>>>>
>>>>>>> --
>>>>>>> //www.freelists.org/webpage/oracle-l
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> --
>>>>>> Maureen English
>>>>>> Lead Database Administrator
>>>>>> University of Alaska
>>>>>> Fairbanks, AK
>>>>>> (907) 450-8329
>>>>>
>>>>>
>>>>>> -- //www.freelists.org/webpage/oracle-l
>>>>> -- //www.freelists.org/webpage/oracle-l
>
> --
> Maureen English
> Lead Database Administrator
> University of Alaska
> Fairbanks, AK
> (907) 450-8329
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