
Hello, I have to move some VMs from FCP based storage domain to iSCSI based storage domain. Can I do it offline or online keeping in mind that: Host1, Host2 have access only to the FCP SD Host3, Host4 have access only to the iSCSI SD They are all managed by the same engine in the same DC but in different cluster I suppose it happens through network, correct? Thanks in advance, Gianluca

Hi, Storage domains are per Data Center, and all hosts in this DC should be able to access the SDs, no matter in which cluster they are... Are you sure your hosts are on the same DC ? Thanks, Freddy On Wed, Mar 8, 2017 at 12:57 PM, Gianluca Cecchi <gianluca.cecchi@gmail.com> wrote:
Hello, I have to move some VMs from FCP based storage domain to iSCSI based storage domain. Can I do it offline or online keeping in mind that:
Host1, Host2 have access only to the FCP SD Host3, Host4 have access only to the iSCSI SD
They are all managed by the same engine in the same DC but in different cluster
I suppose it happens through network, correct? Thanks in advance, Gianluca
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On Wed, Mar 8, 2017 at 1:30 PM, Fred Rolland <frolland@redhat.com> wrote:
Hi,
Storage domains are per Data Center, and all hosts in this DC should be able to access the SDs, no matter in which cluster they are...
Are you sure your hosts are on the same DC ?
Thanks,
Freddy
No, my scenario was a planning workflow. At this moment I only have Host1 and Host2 that are connected to an FC-SAN. I have to move data to an iSCSI storage and also oVirt hosts to Host3 and Host4 (yet to be deployed). So I'm trying to understand if I can do it in pieces bypassing export/import I forgot that it is DC the constraint for SD accessibility. Any suggestion to accomplish the desired target? Thanks, Gianluca

I cannot think of another option other to have an export domain in the middle that can be accessed from all the hosts. On Wed, Mar 8, 2017 at 3:50 PM, Gianluca Cecchi <gianluca.cecchi@gmail.com> wrote:
On Wed, Mar 8, 2017 at 1:30 PM, Fred Rolland <frolland@redhat.com> wrote:
Hi,
Storage domains are per Data Center, and all hosts in this DC should be able to access the SDs, no matter in which cluster they are...
Are you sure your hosts are on the same DC ?
Thanks,
Freddy
No, my scenario was a planning workflow. At this moment I only have Host1 and Host2 that are connected to an FC-SAN. I have to move data to an iSCSI storage and also oVirt hosts to Host3 and Host4 (yet to be deployed). So I'm trying to understand if I can do it in pieces bypassing export/import
I forgot that it is DC the constraint for SD accessibility. Any suggestion to accomplish the desired target?
Thanks, Gianluca

On Wed, Mar 8, 2017 at 3:33 PM, Fred Rolland <frolland@redhat.com> wrote:
I cannot think of another option other to have an export domain in the middle that can be accessed from all the hosts.
On Wed, Mar 8, 2017 at 3:50 PM, Gianluca Cecchi <gianluca.cecchi@gmail.com
wrote:
On Wed, Mar 8, 2017 at 1:30 PM, Fred Rolland <frolland@redhat.com> wrote:
Hi,
Storage domains are per Data Center, and all hosts in this DC should be able to access the SDs, no matter in which cluster they are...
Are you sure your hosts are on the same DC ?
Thanks,
Freddy
No, my scenario was a planning workflow. At this moment I only have Host1 and Host2 that are connected to an FC-SAN. I have to move data to an iSCSI storage and also oVirt hosts to Host3 and Host4 (yet to be deployed). So I'm trying to understand if I can do it in pieces bypassing export/import
I forgot that it is DC the constraint for SD accessibility. Any suggestion to accomplish the desired target?
Thanks, Gianluca
Is it realistic to think something similar to the workflow described below, based on the import storage domain functionality described here: http://www.ovirt.org/develop/release-management/features/storage/importstora... and in particular one of its targets: Transfer VMs between setups without the need to copy the data into and out of the export domain. Prerequisite: - Host1 has network connectivity with Host3 - Host1 is part of a DC that contains an FC based storage domain, composed of SAN LUN A of X Tb - Host3 is part of another DC and has connection in place with iSCSI LUN B of X Tb Workflow: - Stop the VMs that are on the source FC domain - Put source storage domain into maintenance - Detach source storage domain - Clone LUN A to LUN B at low level (eg dd command via network Similar to when you clone an entire disk from a server to another server.... ) - import domain on DC where Host3 lives giving the correct iSCSI parameters... Do the OVF_STORE disks on the storage domain contain information about the fact of it being an FC or an iSCSI storage domain, preventing then a possible import operation? This is a test environment where I would like to transfer 4Tb of data from FC SAN in decommission phase to an iSCSI SAN, and if I can by-pass export / import phases, even giving some downtime, would be good. Thanks for reading, Gianluca

I don't think it will work. We rely heavily on LVM when working with iSCSI and FC and I am not sure how LVM will handle this kind of operation. A storage domain is a VG that contains PVs (LUNS), and each disk is a LV. On Wed, Mar 8, 2017 at 6:02 PM, Gianluca Cecchi <gianluca.cecchi@gmail.com> wrote:
On Wed, Mar 8, 2017 at 3:33 PM, Fred Rolland <frolland@redhat.com> wrote:
I cannot think of another option other to have an export domain in the middle that can be accessed from all the hosts.
On Wed, Mar 8, 2017 at 3:50 PM, Gianluca Cecchi < gianluca.cecchi@gmail.com> wrote:
On Wed, Mar 8, 2017 at 1:30 PM, Fred Rolland <frolland@redhat.com> wrote:
Hi,
Storage domains are per Data Center, and all hosts in this DC should be able to access the SDs, no matter in which cluster they are...
Are you sure your hosts are on the same DC ?
Thanks,
Freddy
No, my scenario was a planning workflow. At this moment I only have Host1 and Host2 that are connected to an FC-SAN. I have to move data to an iSCSI storage and also oVirt hosts to Host3 and Host4 (yet to be deployed). So I'm trying to understand if I can do it in pieces bypassing export/import
I forgot that it is DC the constraint for SD accessibility. Any suggestion to accomplish the desired target?
Thanks, Gianluca
Is it realistic to think something similar to the workflow described below, based on the import storage domain functionality described here: http://www.ovirt.org/develop/release-management/features/ storage/importstoragedomain
and in particular one of its targets: Transfer VMs between setups without the need to copy the data into and out of the export domain.
Prerequisite: - Host1 has network connectivity with Host3 - Host1 is part of a DC that contains an FC based storage domain, composed of SAN LUN A of X Tb - Host3 is part of another DC and has connection in place with iSCSI LUN B of X Tb
Workflow: - Stop the VMs that are on the source FC domain - Put source storage domain into maintenance - Detach source storage domain - Clone LUN A to LUN B at low level (eg dd command via network Similar to when you clone an entire disk from a server to another server.... ) - import domain on DC where Host3 lives giving the correct iSCSI parameters...
Do the OVF_STORE disks on the storage domain contain information about the fact of it being an FC or an iSCSI storage domain, preventing then a possible import operation?
This is a test environment where I would like to transfer 4Tb of data from FC SAN in decommission phase to an iSCSI SAN, and if I can by-pass export / import phases, even giving some downtime, would be good.
Thanks for reading, Gianluca

On Thu, Mar 9, 2017 at 1:01 PM, Fred Rolland <frolland@redhat.com> wrote:
I don't think it will work. We rely heavily on LVM when working with iSCSI and FC and I am not sure how LVM will handle this kind of operation. A storage domain is a VG that contains PVs (LUNS), and each disk is a LV.
Actually I executed several times raw "dd" operations to change internal disks of CentOS servers and in general they did have LVM structures with PV, VGs, LVs inside.... Finally I had some time to test and it seems it worked without problems. I created a storage domain of 50Gb with 2 VMs on it and one of them had also a snapshot. I was able to import at target a dd-copy of it as an iSCSI domain without problems. I also created a template on the source domain, but its import fails: I get no error message at web admin gui level, but no action executed actually... on engine log file level I get an error of this type: 2017-03-19 01:37:24,387+01 ERROR [org.ovirt.engine.core.bll.CommandsFactory] (default task-11) [b7a5ef2f-694f-4d5a-851b-c52a5b1f0104] An exception has occurred while trying to create a command object for command 'ImportVmTemplateFromConfiguration' with parameters 'ImportVmTemplateParameters:{commandId='ad3c8e81-4787-46bf-97cb-fe3bfa9f891e', user='null', commandType='Unknown'}': WELD-000049: Unable to invoke protected final void org.ovirt.engine.core.bll.CommandBase.postConstruct() on org.ovirt.engine.core.bll.exportimport.ImportVmTemplateFromConfigurationCommand@353de47b 2017-03-19 01:37:24,388+01 ERROR [org.ovirt.engine.core.bll.PrevalidatingMultipleActionsRunner] (default task-11) [b7a5ef2f-694f-4d5a-851b-c52a5b1f0104] Failed to execute multiple actions of type 'ImportVmTemplateFromConfiguration': null 2017-03-19 01:37:24,388+01 ERROR [org.ovirt.engine.core.bll.PrevalidatingMultipleActionsRunner] (default task-11) [b7a5ef2f-694f-4d5a-851b-c52a5b1f0104] Exception: java.lang.NullPointerException at org.ovirt.engine.core.bll.NestedCommandFactory.createWrappedCommand(NestedCommandFactory.java:24) [bll.jar:] Does it depend on the method or is there any problem in general in template import for storage domain import? See below for details of the approach used. Full engine logs and vdsm logs on target to crosscheck are here: vdsm logs https://drive.google.com/file/d/0BwoPbcrMv8mvUkhtejMxN0QxTUk/view?usp=sharin... engine logs https://drive.google.com/file/d/0BwoPbcrMv8mvRGpHSU5jOU5IbTQ/view?usp=sharin... Source storage domain consists of a FC LUN of 50Gb Some details of it DC https://drive.google.com/file/d/0BwoPbcrMv8mvN1czUnJXYkR1bVE/view?usp=sharin... General https://drive.google.com/file/d/0BwoPbcrMv8mvTUM2QmxlQ19wOUk/view?usp=sharin... Disks https://drive.google.com/file/d/0BwoPbcrMv8mvM0hRV0dkZF83eTA/view?usp=sharin... DisksSnapshots https://drive.google.com/file/d/0BwoPbcrMv8mvX19HTkdPdnc0V0U/view?usp=sharin... Templates https://drive.google.com/file/d/0BwoPbcrMv8mvMU1fLWkxVW0yM0E/view?usp=sharin... VMs https://drive.google.com/file/d/0BwoPbcrMv8mvTHVsRWx5WWNUU0k/view?usp=sharin... I used a nested 4.1 ovirt as a target environment, with: - one CentOS 7.3 vm for engine - one CentOS 7.3 vm for host - one vm for iSCSI target, using NAS4Free (very nice, I didn't know it before this test...) - source lun (ovmsrv06) [root@ovmsrv06 ~]# fdisk -l /dev/mapper/3600a0b80002999020000d2d358c2564b Disk /dev/mapper/3600a0b80002999020000d2d358c2564b: 53.7 GB, 53687091200 bytes, 104857600 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes - I preliminarily access the target LUN through an helper CentOS 7.3 vm c7service, with iSCSI initiator utils [root@c7service log]# fdisk -l /dev/sdb Disk /dev/sdb: 53.7 GB, 53687091200 bytes, 104857600 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 4096 bytes / 1048576 bytes - after detaching the source storage domain as described before, as the source and target luns are not accessible from the same machine, so I use my client to transfer using a local fifo and compressing the data along the way (old stye method used in mid '90 to create compressed Oracle exports when storage constrints was indeed a serious problem.... learnt at that time from the Unix guru Riccardo Ravelli ;-) $ mkfifo travaso - start reading from fifo and writing to target LUN over ssh [g.cecchi@ope46 ~]$ cat travaso | ssh root@c7service"gunzip | dd bs=1024k of=/dev/sdb" (at the end I will have root@c7service's password: 20133+538064 records in 20133+538064 records out 53687091200 bytes (54 GB) copied, 1981.52 s, 27.1 MB/s ) - read from source LUN at ovmsrv06 writing to local fifo in gzip format $ ssh root@ovmsrv06 "time dd if=/dev/mapper/3600a0b80002999020000d2d358c2564b bs=1024k | gzip " | dd bs=1024k of=travaso root@ovmsrv06 password: (at the end I'll have 51200+0 records in 51200+0 records out 53687091200 bytes (54 GB) copied, 1973.41 s, 27.2 MB/s real 32m53.418s user 26m48.461s sys 3m25.484s 0+1314903 records in 0+1314903 records out 21906833820 bytes (22 GB, 20 GiB) copied, 1975.71 s, 11.1 MB/s ) - I create the target iSCSI oVirt environment and then select import domain and give the provided iSCSI LUN. Some details of what I see now on target import 1 https://drive.google.com/file/d/0BwoPbcrMv8mvSnpWcS1TWWV5VDg/view?usp=sharin... general https://drive.google.com/file/d/0BwoPbcrMv8mvQm9yNDFicklfeDg/view?usp=sharin... template import tab https://drive.google.com/file/d/0BwoPbcrMv8mvU0VHQ1NVWHpmdm8/view?usp=sharin... vm import tab https://drive.google.com/file/d/0BwoPbcrMv8mvTVhDY01NRUVCMzQ/view?usp=sharin... import vm step https://drive.google.com/file/d/0BwoPbcrMv8mvUFAweUE4cTk0LWs/view?usp=sharin... disks pre-import https://drive.google.com/file/d/0BwoPbcrMv8mvVjBmc3RwWXg1ak0/view?usp=sharin... disks after import https://drive.google.com/file/d/0BwoPbcrMv8mvU3pfTnhxWmROS3M/view?usp=sharin... virtual machines list, after import https://drive.google.com/file/d/0BwoPbcrMv8mvM1VJcWZBaDA1ckU/view?usp=sharin... snapshot view https://drive.google.com/file/d/0BwoPbcrMv8mvdGZWWE9CbGR6aEE/view?usp=sharin... events https://drive.google.com/file/d/0BwoPbcrMv8mvOHVFWEp2a1VnenM/view?usp=sharin... Let me know if further info necessary to debug the template import problem... Gianluca

On Mon, Mar 20, 2017 at 5:56 PM, Gianluca Cecchi <gianluca.cecchi@gmail.com> wrote:
On Thu, Mar 9, 2017 at 1:01 PM, Fred Rolland <frolland@redhat.com> wrote:
I don't think it will work. We rely heavily on LVM when working with iSCSI and FC and I am not sure how LVM will handle this kind of operation. A storage domain is a VG that contains PVs (LUNS), and each disk is a LV.
Actually I executed several times raw "dd" operations to change internal disks of CentOS servers and in general they did have LVM structures with PV, VGs, LVs inside....
Finally I had some time to test and it seems it worked without problems. I created a storage domain of 50Gb with 2 VMs on it and one of them had also a snapshot. I was able to import at target a dd-copy of it as an iSCSI domain without problems. I also created a template on the source domain, but its import fails: I get no error message at web admin gui level, but no action executed actually... on engine log file level I get an error of this type:
2017-03-19 01:37:24,387+01 ERROR [org.ovirt.engine.core.bll.CommandsFactory] (default task-11) [b7a5ef2f-694f-4d5a-851b-c52a5b1f0104] An exception has occurred while trying to create a command object for command ' ImportVmTemplateFromConfiguration' with parameters 'ImportVmTemplateParameters:{commandId='ad3c8e81-4787-46bf-97cb-fe3bfa9f891e', user='null', commandType='Unknown'}': WELD-000049: Unable to invoke protected final void org.ovirt.engine.core.bll.CommandBase.postConstruct() on org.ovirt.engine.core.bll.exportimport.ImportVmTemplateFromConfigurat ionCommand@353de47b 2017-03-19 01:37:24,388+01 ERROR [org.ovirt.engine.core.bll. PrevalidatingMultipleActionsRunner] (default task-11) [b7a5ef2f-694f-4d5a-851b-c52a5b1f0104] Failed to execute multiple actions of type 'ImportVmTemplateFromConfiguration': null 2017-03-19 01:37:24,388+01 ERROR [org.ovirt.engine.core.bll. PrevalidatingMultipleActionsRunner] (default task-11) [b7a5ef2f-694f-4d5a-851b-c52a5b1f0104] Exception: java.lang.NullPointerException at org.ovirt.engine.core.bll.NestedCommandFactory. createWrappedCommand(NestedCommandFactory.java:24) [bll.jar:]
Does it depend on the method or is there any problem in general in template import for storage domain import? See below for details of the approach used. Full engine logs and vdsm logs on target to crosscheck are here:
vdsm logs https://drive.google.com/file/d/0BwoPbcrMv8mvUkhtejMxN0QxTUk/ view?usp=sharing
engine logs https://drive.google.com/file/d/0BwoPbcrMv8mvRGpHSU5jOU5IbTQ/ view?usp=sharing
Any comment to previous e-mail? Are there any known problems with template import? Any chance to see the error logs provided? Thanks, Gianluca

On Thu, Mar 23, 2017 at 11:26 AM, Gianluca Cecchi <gianluca.cecchi@gmail.com
wrote:
On Mon, Mar 20, 2017 at 5:56 PM, Gianluca Cecchi < gianluca.cecchi@gmail.com> wrote:
On Thu, Mar 9, 2017 at 1:01 PM, Fred Rolland <frolland@redhat.com> wrote:
I don't think it will work. We rely heavily on LVM when working with iSCSI and FC and I am not sure how LVM will handle this kind of operation. A storage domain is a VG that contains PVs (LUNS), and each disk is a LV.
Actually I executed several times raw "dd" operations to change internal disks of CentOS servers and in general they did have LVM structures with PV, VGs, LVs inside....
Any comment to previous e-mail? Are there any known problems with template import? Any chance to see the error logs provided? Thanks, Gianluca
I confirm that I was able to transfer with the same method my FC based 1Tb storage domain to an iSCSI LUN and then import it. I didn't have templates on it so I could not verify if the problem related to template import that I previously had still present. Gianluca
participants (2)
-
Fred Rolland
-
Gianluca Cecchi