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

[Nicolas Ecarnot]

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