Re: [ovirt-users] shared storage with iscsi
On 12/04/2014 02:54 PM, mad Engineer wrote: sorry i am wrong its the data domain that stores virtual disk images,I have no idea how ovirt shares block device across hosts.Looks like i need to try that for understanding how its implemented.In case of vmware they uses vmfs file system for sharing block device among hosts.I currently have no issues with my NFS shared storage so dont have any plan to use iscsi,but just curious how the implementation is. It's not shared considering the lowest level. Each disk corresponds to a LVM logical volume, which is activated only on the specific hypervisor running the VM. Others hypervisors cannot access the logical volume while the VM is not running on it (except for shared disks). To activate the logical volume (in order to run the VM), hypervisor runs a "lvchange -ay vol_group/logical_vol" In my existing non ovirt environment,SAN block devices is exported and its shared using GFS.Is ovirt using any simillar method to achieve shared block device. On Thu, Dec 4, 2014 at 9:10 PM, mad Engineer wrote: Thanks Gianluca,it says only NFS is supported as export domain.I believe export domain is the one i am currently using for live migrating vms across hosts.So iscsi is not supported,please correct me if i am wrong.Thanks for your help On Thu, Dec 4, 2014 at 9:00 PM, Gianluca Cecchi wrote: On Thu, Dec 4, 2014 at 4:23 PM, mad Engineer wrote: Thanks Maor,in non ovirt kvm setup i use GFS2 to make the block device shareable across multiple hosts.Could you tell me how is it achieved in ovirt. Regards First step the admin guide: http://www.ovirt.org/OVirt_Administration_Guide and in particular the Storage chapter and the related iSCSI part: http://www.ovirt.org/OVirt_Administration_Guide#.E2.81.A0Storage Also, for multipath in case you need it: http://www.ovirt.org/Feature/iSCSI-Multipath HIH, Gianluca ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Re: [ovirt-users] shared storage with iscsi
On Thu, Dec 4, 2014 at 12:54 PM, mad Engineer wrote: > sorry i am wrong its the data domain that stores virtual disk images,I > have no idea how ovirt shares block device across hosts.Looks like i > need to try that for understanding how its implemented.In case of > vmware they uses vmfs file system for sharing block device among > hosts.I currently have no issues with my NFS shared storage so dont > have any plan to use iscsi,but just curious how the implementation > is.In my existing non ovirt environment,SAN block devices is exported > and its shared using GFS.Is ovirt using any simillar method to achieve > shared block device. > > oVirt uses a different approach altogether (this is why it can scale to clusters with hundreds of hosts, unlike vmware). The idea is pretty simple 1. format the shared block storage with LVM 2. Every VM disk image is an LV 3. manage host access to separate LVs using simple lvchange. Of course there's much more to the way this is implemented, but very simply - no two hosts have write access to the same LV, unless it is specified as a shared disk, so no clustered FS is needed, no scsi reservations are needed and this concept scales, unlike vmfs, gfs, and other such systems. > > > On Thu, Dec 4, 2014 at 9:10 PM, mad Engineer > wrote: > > Thanks Gianluca,it says only NFS is supported as export domain.I > > believe export domain is the one i am currently using for live > > migrating vms across hosts.So iscsi is not supported,please correct me > > if i am wrong.Thanks for your help > > > > On Thu, Dec 4, 2014 at 9:00 PM, Gianluca Cecchi > > wrote: > >> On Thu, Dec 4, 2014 at 4:23 PM, mad Engineer > >> wrote: > >>> > >>> Thanks Maor,in non ovirt kvm setup i use GFS2 to make the block device > >>> shareable across multiple hosts.Could you tell me how is it achieved > >>> in ovirt. > >>> > >>> Regards > >>> > >> > >> First step the admin guide: > >> http://www.ovirt.org/OVirt_Administration_Guide > >> > >> and in particular the Storage chapter and the related iSCSI part: > >> http://www.ovirt.org/OVirt_Administration_Guide#.E2.81.A0Storage > >> > >> Also, for multipath in case you need it: > >> http://www.ovirt.org/Feature/iSCSI-Multipath > >> > >> HIH, > >> Gianluca > ___ > Users mailing list > Users@ovirt.org > http://lists.ovirt.org/mailman/listinfo/users > ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Re: [ovirt-users] shared storage with iscsi
sorry i am wrong its the data domain that stores virtual disk images,I have no idea how ovirt shares block device across hosts.Looks like i need to try that for understanding how its implemented.In case of vmware they uses vmfs file system for sharing block device among hosts.I currently have no issues with my NFS shared storage so dont have any plan to use iscsi,but just curious how the implementation is.In my existing non ovirt environment,SAN block devices is exported and its shared using GFS.Is ovirt using any simillar method to achieve shared block device. On Thu, Dec 4, 2014 at 9:10 PM, mad Engineer wrote: > Thanks Gianluca,it says only NFS is supported as export domain.I > believe export domain is the one i am currently using for live > migrating vms across hosts.So iscsi is not supported,please correct me > if i am wrong.Thanks for your help > > On Thu, Dec 4, 2014 at 9:00 PM, Gianluca Cecchi > wrote: >> On Thu, Dec 4, 2014 at 4:23 PM, mad Engineer >> wrote: >>> >>> Thanks Maor,in non ovirt kvm setup i use GFS2 to make the block device >>> shareable across multiple hosts.Could you tell me how is it achieved >>> in ovirt. >>> >>> Regards >>> >> >> First step the admin guide: >> http://www.ovirt.org/OVirt_Administration_Guide >> >> and in particular the Storage chapter and the related iSCSI part: >> http://www.ovirt.org/OVirt_Administration_Guide#.E2.81.A0Storage >> >> Also, for multipath in case you need it: >> http://www.ovirt.org/Feature/iSCSI-Multipath >> >> HIH, >> Gianluca ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Re: [ovirt-users] shared storage with iscsi
On 12/04/2014 12:40 PM, mad Engineer wrote: Thanks Gianluca,it says only NFS is supported as export domain. That's right. I believe export domain is the one i am currently using for live migrating vms across hosts. That's not true. You're not using the Export Domain to support live migrations. Your VMs are running in a regular Storage Domain (not Export Domain), probably NFS, and it could be iscsi. So iscsi is not supported,please correct me if i am wrong.Thanks for your help On Thu, Dec 4, 2014 at 9:00 PM, Gianluca Cecchi wrote: On Thu, Dec 4, 2014 at 4:23 PM, mad Engineer wrote: Thanks Maor,in non ovirt kvm setup i use GFS2 to make the block device shareable across multiple hosts.Could you tell me how is it achieved in ovirt. Regards First step the admin guide: http://www.ovirt.org/OVirt_Administration_Guide and in particular the Storage chapter and the related iSCSI part: http://www.ovirt.org/OVirt_Administration_Guide#.E2.81.A0Storage Also, for multipath in case you need it: http://www.ovirt.org/Feature/iSCSI-Multipath HIH, Gianluca ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Re: [ovirt-users] shared storage with iscsi
Le 04/12/2014 16:40, mad Engineer a écrit : Thanks Gianluca,it says only NFS is supported as export domain.I believe export domain is the one i am currently using for live migrating vms across hosts.So iscsi is not supported,please correct me if i am wrong.Thanks for your help Sorry I did not read you were speaking about _EXPORT_ domain. Then indeed, you're right, iSCSI is not supported for export domains. In our case, we are providing some iSCSI LUNs as export domains via the managers which are serving them as NFS shares. Performance is OK. On Thu, Dec 4, 2014 at 9:00 PM, Gianluca Cecchi wrote: On Thu, Dec 4, 2014 at 4:23 PM, mad Engineer wrote: Thanks Maor,in non ovirt kvm setup i use GFS2 to make the block device shareable across multiple hosts.Could you tell me how is it achieved in ovirt. Regards First step the admin guide: http://www.ovirt.org/OVirt_Administration_Guide and in particular the Storage chapter and the related iSCSI part: http://www.ovirt.org/OVirt_Administration_Guide#.E2.81.A0Storage Also, for multipath in case you need it: http://www.ovirt.org/Feature/iSCSI-Multipath HIH, Gianluca ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users -- Nicolas Ecarnot ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Re: [ovirt-users] shared storage with iscsi
Thanks Gianluca,it says only NFS is supported as export domain.I believe export domain is the one i am currently using for live migrating vms across hosts.So iscsi is not supported,please correct me if i am wrong.Thanks for your help On Thu, Dec 4, 2014 at 9:00 PM, Gianluca Cecchi wrote: > On Thu, Dec 4, 2014 at 4:23 PM, mad Engineer > wrote: >> >> Thanks Maor,in non ovirt kvm setup i use GFS2 to make the block device >> shareable across multiple hosts.Could you tell me how is it achieved >> in ovirt. >> >> Regards >> > > First step the admin guide: > http://www.ovirt.org/OVirt_Administration_Guide > > and in particular the Storage chapter and the related iSCSI part: > http://www.ovirt.org/OVirt_Administration_Guide#.E2.81.A0Storage > > Also, for multipath in case you need it: > http://www.ovirt.org/Feature/iSCSI-Multipath > > HIH, > Gianluca ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Re: [ovirt-users] shared storage with iscsi
On Thu, Dec 4, 2014 at 4:23 PM, mad Engineer wrote: > Thanks Maor,in non ovirt kvm setup i use GFS2 to make the block device > shareable across multiple hosts.Could you tell me how is it achieved > in ovirt. > > Regards > > First step the admin guide: http://www.ovirt.org/OVirt_Administration_Guide and in particular the Storage chapter and the related iSCSI part: http://www.ovirt.org/OVirt_Administration_Guide#.E2.81.A0Storage Also, for multipath in case you need it: http://www.ovirt.org/Feature/iSCSI-Multipath HIH, Gianluca ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Re: [ovirt-users] shared storage with iscsi
Le 04/12/2014 16:23, mad Engineer a écrit : Thanks Maor,in non ovirt kvm setup i use GFS2 to make the block device shareable across multiple hosts.Could you tell me how is it achieved in ovirt. When using iSCSI, they are not shared. You have to make sure your storage infrastructure allows multiple connection to the iscsi LUN. But there is nothing to do about sharing on the block level. When migrating data in iSCSI environement, according to what I've witnessed, blocks are dd'ed (so this takes time) from the SD source to target. I guess that's where glusterfs adds some benefit. Regards On Thu, Dec 4, 2014 at 5:31 PM, Maor Lipchuk wrote: - Original Message - From: "mad Engineer" To: users@ovirt.org Sent: Thursday, December 4, 2014 11:26:32 AM Subject: [ovirt-users] shared storage with iscsi Hello All, I am using NFS as shared storage and is working fine,able to migrate instances across nodes. Is it possible to use iscsi backend and achieve the same,a shared iscsi[i am not able to find a way to do a shared iscsi across hosts] can some one help with a shared iscsi storage for live migration of vm across hosts Thanks ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users Hi, What do you mean by shared iscsi? if you created a new iSCSI Storage Domain in the Data Center and it is active then all the hosts should see it while it is Active. Regards, Maor ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users -- Nicolas Ecarnot ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Re: [ovirt-users] shared storage with iscsi
Thanks Maor,in non ovirt kvm setup i use GFS2 to make the block device shareable across multiple hosts.Could you tell me how is it achieved in ovirt. Regards On Thu, Dec 4, 2014 at 5:31 PM, Maor Lipchuk wrote: > > > - Original Message - >> From: "mad Engineer" >> To: users@ovirt.org >> Sent: Thursday, December 4, 2014 11:26:32 AM >> Subject: [ovirt-users] shared storage with iscsi >> >> Hello All, >> I am using NFS as shared storage and is working fine,able >> to migrate instances across nodes. >> Is it possible to use iscsi backend and achieve the same,a shared >> iscsi[i am not able to find a way to do a shared iscsi across hosts] >> can some one help with a shared iscsi storage for live migration of vm >> across hosts >> >> Thanks >> ___ >> Users mailing list >> Users@ovirt.org >> http://lists.ovirt.org/mailman/listinfo/users >> > > Hi, > > What do you mean by shared iscsi? > if you created a new iSCSI Storage Domain in the Data Center and it is active > then all the hosts should see it while it is Active. > > Regards, > Maor ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Re: [ovirt-users] shared storage with iscsi
- Original Message - > From: "mad Engineer" > To: users@ovirt.org > Sent: Thursday, December 4, 2014 11:26:32 AM > Subject: [ovirt-users] shared storage with iscsi > > Hello All, > I am using NFS as shared storage and is working fine,able > to migrate instances across nodes. > Is it possible to use iscsi backend and achieve the same,a shared > iscsi[i am not able to find a way to do a shared iscsi across hosts] > can some one help with a shared iscsi storage for live migration of vm > across hosts > > Thanks > ___ > Users mailing list > Users@ovirt.org > http://lists.ovirt.org/mailman/listinfo/users > Hi, What do you mean by shared iscsi? if you created a new iSCSI Storage Domain in the Data Center and it is active then all the hosts should see it while it is Active. Regards, Maor ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
