[one-users] iscsi target as a guest disk

[Jaime Melis]

Hi,

you should use tm_shared instead of tm_ssh (tm_lvm won't work either for
your setup).

Regarding your first issue: managing iscsi targets with OpenNebula, there
is no native way to handle iscsi block devices with OpenNebula. What you
can do out-of-the-box is to use any block device available in the target
host (just like you're trying to do in the above logs), whether it's iscsi
or not. However I reckon that's too limited for your scenario, since it
requires an administrator to discover the iscsi targets on the target host.

We've opened a ticket to provide native support for iscsi targets (planned
for OpenNebula 3.4):
http://dev.opennebula.org/issues/1032

We've been thinking about the possible implementation, and for the moment
we believe the best approach will be the following:

1) Define a iscsi handler, such as: iscsi://hostname/target, which will be
used in image templates under the SOURCE attribute:
DISK = [ TYPE = block, SOURCE="iscsi://my-san/my-lun", TARGET = "hda",
CLONE=NO]

2) Modify the TM drivers to handle in a specific way sources starting with
"iscsi://" (just like we did in tm_lvm for "/dev/*" devices [1])
The driver will run a re-scan of the iscsi targets, and create a symlink
for "disk.0" to point to the new /dev/ device.

[1]
https://github.com/OpenNebula/one/blob/master/src/tm_mad/lvm/tm_clone.sh#L70

Regards,
Jaime

On Thu, Dec 15, 2011 at 9:52 AM, Prakhar Srivastava
<prakhar.apj at gmail.com>wrote:

> Hi,
> It appears that you are using the tm_ssh transfer drivers. Use tm_lvm
> transfer manager drivers instead.
>
> Prakhar
>
>
> On Thu, Dec 15, 2011 at 2:01 PM, Tengvall, Ilkka (NSN - FI Espoo) <
> ilkka.tengvall at nsn.com> wrote:
>
>> Hi,
>>
>> I'm writing related to issue:
>>
>> http://dev.opennebula.org/issues/1025
>>
>> Ruben, thanks for answer, you commented there that iscsi could be used
>> as a disk:
>>
>> "you should be able to use iSCSI block devices with
>> DISK=[TYPE=block,SOURCE=<path_to_dev>....]."
>>
>> I tried to follow you instruction, I don't see it working. What am I
>> missing, since the oned tries to cp the iscsi image, instead as pass it
>> to guest as disk:
>>
>> --------------------------------
>> $ cat
>> iscsi-vm.txt
>>
>> NAME=f16-min-iscsi
>> USER=oneadmin
>> GROUP=oneadmin
>> PUBLIC=No
>>
>> DISK=[
>>  BUS=virtio,
>>  TYPE=block,
>>
>>
>> SOURCE=/dev/disk/by-path/ip-192.168.117.1:3260-iscsi-iqn.2009-02.net.nsn-net:whipper.f16-min-lun-0
>> ]
>> GRAPHICS=[
>>  KEYMAP=fi,
>>  TYPE=vnc ]
>> INPUT=[
>>  BUS=usb,
>>  TYPE=mouse ]
>> MEMORY=512
>> NIC=[
>>  NETWORK_ID=1,
>>  WHITE_PORTS_TCP=22 ]
>> OS=[
>>  ARCH=x86_64,
>>  BOOT=hd ]
>> RAW=[
>>  TYPE=kvm ]
>> VCPU=1
>> --------------------------------
>>
>> Creating the machine using the disk:
>>
>> --------------------------------
>> $ onevm create iscsi-vm.txt
>> ID: 10
>> --------------------------------
>>
>> and after it fails I see from the logs that it tried to copy the image
>> (cp), instead of passing it to libvirt as a virtio device:
>>
>> --------------------------------
>> Thu Dec 15 10:26:09 2011 [DiM][I]: New VM state is ACTIVE.
>> Thu Dec 15 10:26:09 2011 [LCM][I]: New VM state is PROLOG.
>> Thu Dec 15 10:26:09 2011 [VM][I]: Virtual Machine has no context
>> Thu Dec 15 10:26:09 2011 [TM][I]: Command execution fail:
>> /usr/lib/one/tm_commands/shared/tm_clone.sh
>>
>> /dev/disk/by-path/ip-192.168.117.1:3260-iscsi-iqn.2009-02.net.nsn-net:whipper.f16-min-lun-0
>> onebula:/var/lib/one//10/images/disk.0
>> Thu Dec 15 10:26:09 2011 [TM][D]: tm_clone.sh:
>>
>> /dev/disk/by-path/ip-192.168.117.1:3260-iscsi-iqn.2009-02.net.nsn-net:whipper.f16-min-lun-0
>> onebula:/var/lib/one//10/images/disk.0
>> Thu Dec 15 10:26:09 2011 [TM][D]: tm_clone.sh: DST:
>> /var/lib/one//10/images/disk.0
>> Thu Dec 15 10:26:09 2011 [TM][I]: tm_clone.sh: Creating directory
>> /var/lib/one//10/images
>> Thu Dec 15 10:26:09 2011 [TM][I]: tm_clone.sh: Executed "mkdir -p
>> /var/lib/one//10/images".
>> Thu Dec 15 10:26:09 2011 [TM][I]: tm_clone.sh: Executed "chmod a+w
>> /var/lib/one//10/images".
>> Thu Dec 15 10:26:09 2011 [TM][I]: tm_clone.sh: Cloning
>> 3260-iscsi-iqn.2009-02.net.nsn-net:whipper.f16-min-lun-0
>> Thu Dec 15 10:26:09 2011 [TM][E]: tm_clone.sh: Command "cp -r
>> 3260-iscsi-iqn.2009-02.net.nsn-net:whipper.f16-min-lun-0
>> /var/lib/one//10/images/disk.0" failed.
>> Thu Dec 15 10:26:09 2011 [TM][E]: tm_clone.sh: cp: cannot stat
>> `3260-iscsi-iqn.2009-02.net.nsn-net:whipper.f16-min-lun-0': No such file
>> or directory
>> Thu Dec 15 10:26:09 2011 [TM][E]: Error copying
>>
>> /dev/disk/by-path/ip-192.168.117.1:3260-iscsi-iqn.2009-02.net.nsn-net:whipper.f16-min-lun-0
>> to onebula:/var/lib/one//10/images/disk.0
>> Thu Dec 15 10:26:09 2011 [TM][I]: ExitCode: 1
>> Thu Dec 15 10:26:09 2011 [TM][E]: Error excuting image transfer script:
>> Error copying
>>
>> /dev/disk/by-path/ip-192.168.117.1:3260-iscsi-iqn.2009-02.net.nsn-net:whipper.f16-min-lun-0
>> to onebula:/var/lib/one//10/images/disk.0
>> Thu Dec 15 10:26:09 2011 [DiM][I]: New VM state is FAILED
>> --------------------------------
>>
>> Thanks for the answer so far.
>>
>>
>> On 2011-12-12 15:33, ext Tengvall, Ilkka (NSN - FI Espoo) wrote:
>> > Hi,
>> >
>> > I'm new to Open Nebula, and have some questions. First one would be
>> > about iscsi support. I can't find any reference from oned documents
>> > itself about iscsi. Is it possible to configure guests  using iscsi lun
>> > from remote server as a os block device?
>> >
>> > I have done it using libvirt, so it works, but how to map this to oned
>> > configs?
>> >
>> > another way which would also work would be booting kernel directly or
>> > via ipxe and give it iscsi as a root device. Both of those work too.
>> >
>> > Is there a way to do this in oned?
>> >
>> > I found an old related posting here, but I don't know if it ever led to
>> > anything:
>> >
>> >
>> http://lists.opennebula.org/htdig.cgi/users-opennebula.org/2009-July/000599.html
>> >
>>
>>
>> --
>> Ilkka Tengvall
>> Senior Specialist, Linux & Virtualization Architecture
>>
>> _______________________________________________
>> Users mailing list
>> Users at lists.opennebula.org
>> http://lists.opennebula.org/listinfo.cgi/users-opennebula.org
>>
>
>
> _______________________________________________
> Users mailing list
> Users at lists.opennebula.org
> http://lists.opennebula.org/listinfo.cgi/users-opennebula.org
>
>


-- 
Jaime Melis
Project Engineer
OpenNebula - The Open Source Toolkit for Cloud Computing
www.OpenNebula.org | jmelis at opennebula.org
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.opennebula.org/pipermail/users-opennebula.org/attachments/20111215/39a8c79e/attachment-0003.htm>