[Users] Fail to connect to an iSCSI Eq. LUN

[Nicolas Ecarnot]

Too bad : I did not change anything, and time passing by, it all came to 
work...

Damn, this is the worst sysadmin situation : this is working, and you 
don't know why !


Seriously : it indeed appears that the choice of shared access is the 
good one (until someone proves it wrong).

More seriously : I shut down the second node, and made the conection 
with only the first node alive.
In that case, no possible conflict.

-- 
Nicolas Ecarnot

Le 16/01/2013 15:12, Nicolas Ecarnot a écrit :
> Hi,
>
> As a beginner, I'm reading again and again, but I'm not sure of the best
> way to do :
>
> Through the oVirt web manager, I'm trying to create an iSCSI storage
> domain.
> On my Equalogic SAN, I've created a volume with no restriction access
> (for the time being).
> I have two hypervisors on which I'm quite sure my network config is good
> enough for now (two nics bonded for the management, and 2 nics bonded
> for the iscsi). Everything is pinging ok. Networking is not an issue.
>
> In the ovirt web manager, I try to create the very first storage domain,
> of iscsi type of course.
> I choose one of the node, then the iscsi discovery + login is working fine.
> I can see my Equalogic volume, I'm checking it, and saving with the OK
> button, and I get the following error :
>
>> "Error while executing action New SAN Storage Domain: Physical device
>> initialization failed. Check that the device is empty. Please remove
>> all files and partitions from the device."
>
> Not very interesting, but the node log file is more instructive :
>
>> Thread-2767::INFO::2013-01-16
>> 13:35:57,064::logUtils::37::dispatcher::(wrapper) Run and protect:
>> createVG(vgname='7becc578-a94b-41f4-bbec-8df5fe9f46c0',
>> devlist=['364ed2ad5297bb022fd0ee5ba36ad91a0'], options=None)
>>
>> Thread-2767::DEBUG::2013-01-16
>> 13:35:57,066::__init__::1249::Storage.Misc.excCmd::(_log) '/usr/bin/sudo
>> -n /sbin/lvm pvcreate --config " devices { preferred_names =
>> [\\"^/dev/mapper/\\"] ignore_suspended_devices=1 write_cache_state=0
>> disable_after_error_count=3 filter = [
>> \\"a%3600508e000000000ec7b6d8dea602b0e|364ed2ad5297bb022fd0ee5ba36ad91a0%\\",
>>
>> \\"r%.*%\\" ] }  global {  locking_type=1  prioritise_write_locks=1
>> wait_for_locks=1 }  backup {  retain_min = 50  retain_days = 0 } "
>> --metadatasize 128m --metadatacopies 2 --metadataignore y
>> /dev/mapper/364ed2ad5297bb022fd0ee5ba36ad91a0' (cwd None)
>>
>> Thread-2767::DEBUG::2013-01-16
>> 13:35:57,147::__init__::1249::Storage.Misc.excCmd::(_log) FAILED: <err>
>> = "  Can't open /dev/mapper/364ed2ad5297bb022fd0ee5ba36ad91a0
>> exclusively.  Mounted filesystem?\n"; <rc> = 5
>>
>> Thread-2767::DEBUG::2013-01-16
>> 13:35:57,149::__init__::1249::Storage.Misc.excCmd::(_log) '/usr/bin/sudo
>> -n /sbin/lvm pvs --config " devices { preferred_names =
>> [\\"^/dev/mapper/\\"] ignore_suspended_devices=1 write_cache_state=0
>> disable_after_error_count=3 filter = [
>> \\"a%3600508e000000000ec7b6d8dea602b0e|364ed2ad5297bb022fd0ee5ba36ad91a0%\\",
>>
>> \\"r%.*%\\" ] }  global {  locking_type=1  prioritise_write_locks=1
>> wait_for_locks=1 }  backup {  retain_min = 50  retain_days = 0 } " -o
>> vg_name,pv_name --noheading
>> /dev/mapper/364ed2ad5297bb022fd0ee5ba36ad91a0' (cwd None)
>>
>> Thread-2767::DEBUG::2013-01-16
>> 13:35:57,224::__init__::1249::Storage.Misc.excCmd::(_log) FAILED: <err>
>> = '  No physical volume label read from
>> /dev/mapper/364ed2ad5297bb022fd0ee5ba36ad91a0\n  Failed to read physical
>> volume "/dev/mapper/364ed2ad5297bb022fd0ee5ba36ad91a0"\n'; <rc> = 5
>>
>> Thread-2767::ERROR::2013-01-16
>> 13:35:57,226::task::853::TaskManager.Task::(_setError)
>> Task=`1c5b8931-0085-489c-8962-ff5cc1323dc7`::Unexpected error
>>
>> Traceback (most recent call last):
>>   File "/usr/share/vdsm/storage/task.py", line 861, in _run
>>   File "/usr/share/vdsm/logUtils.py", line 38, in wrapper
>>   File "/usr/share/vdsm/storage/hsm.py", line 1680, in createVG
>>   File "/usr/share/vdsm/storage/lvm.py", line 788, in createVG
>>   File "/usr/share/vdsm/storage/lvm.py", line 631, in _initpvs
>> PhysDevInitializationError: Failed to initialize physical device:
>> ("found: {} notFound:
>> ('/dev/mapper/364ed2ad5297bb022fd0ee5ba36ad91a0',)",)
>
>
> I guess the interesting part is :
>
>> Can't open /dev/mapper/364ed2ad5297bb022fd0ee5ba36ad91a0 exclusively.
>> Mounted filesystem?
>
> On any node, this partition is not mounted.
> But I have set up the access to this volume as "shared" on the Equalogic
> SAN, not knowing whether I should do so? I see both nodes connected on
> the same volume.
> I tried to remove this permit, but it didn't help.
>
> I also found Redhat answering such a question :
>
>> There are two ways to clear this error:
>>
>>     - Remove VG from the Storage LUN using vgremove command. Run this
>> command from one of the hypervisors.
>>     - Clear the first 4K from the disk . Execute the following from
>> one of the hypervisors:
>>
>>     # dd if=/dev/zero of=/dev/mapper/diskname bs=4k count=1
>
> I did try that, but with no luck.
>
>
>
> Now, two things :
>
> - Do I have to keep the access to this volume shared/allowed to all the
> hypervisors dedicated to this volume?
> - What is the problem with the pvcreate command?
>


-- 
Nicolas Ecarnot