Re: [ovirt-users] [ovirt-devel] hosted-engine setup/migration features for 3.6
- Original Message - > From: "Yedidyah Bar David" > To: "Bob Doolittle" > Cc: "users" , "devel" > Sent: Wednesday, December 3, 2014 3:04:17 PM > Subject: Re: [ovirt-devel] hosted-engine setup/migration features for 3.6 > > - Original Message - > > From: "Bob Doolittle" > > To: "Yedidyah Bar David" > > Sent: Wednesday, December 3, 2014 2:50:12 PM > > Subject: Re: [ovirt-devel] hosted-engine setup/migration features for 3.6 > > > > Another issue with that page is that it assumes a remote database. I am not > > sure what percentage of cases have remote databases but clearly many > > (most?) do not, since that's not default behavior. > > I agree. > > > So that page definitely > > needs attention. See: > > https://bugzilla.redhat.com/show_bug.cgi?id=105 > > Indeed. Note that this isn't specific to hosted-engine, it's the same for > any migration using engine-backup to backup/restore, therefore there is > a link to its page in the top, where this is more detailed. I now added another note next to the restore text. > We also have > a bug [3] to automate this. > > [3] https://bugzilla.redhat.com/show_bug.cgi?id=1064503 > > > https://bugzilla.redhat.com/show_bug.cgi?id=108 > > > > Some of us have wanted to disable global maintenance upon bootup by adding > > a systemd service on Fedora 20 (since you must enable global maintenance to > > shut it down cleanly), and have found it impossible to create the necessary > > systemd dependencies. It seems that (at least with 3.4) hosted-engine > > --set-maintenance --mode=none will return an error for several seconds > > after all other services have started and it's not clear what can be waited > > upon in order to issue the command with assurance it will complete > > successfully. This isn't strictly a setup/migration issue but it is an > > issue with setting up a desired configuration with hosted-engine. The way > > to reproduce this is simply to wait until gdm-greeter displays the login > > prompt, ssh into the system and execute hosted-engine --set-maintenance > > --mode=none and observe the error. Or create a systemd service that depends > > upon (waits for) the latest-possible service, try executing the command > > there, and observe the error. Ideally there would be some external > > observable event which a systemd service could depend upon, when > > hosted-engine is ready to do its thing. > > Adding Jiri for that. Do you have an open bug? > > Thanks, > > > > > Regards, > > Bob > > > > > > On Wed, Dec 3, 2014 at 2:59 AM, Yedidyah Bar David wrote: > > > > > Hi all, > > > > > > We already have quite a lot of open ovirt-hosted-engine-setup bugs for > > > 3.6 > > > [1]. > > > > > > Yesterday I tried helping someone on irc who planned to migrate to > > > hosted-engine > > > manually, and without knowing (so it seems) that such a feature exists. > > > He > > > had > > > an engine set up on a physical host, prepared a VM for it, and asked > > > about > > > migrating > > > the engine to the VM. In principle this works, but the final result will > > > be a > > > hosted-engine, where the engine manages a VM the runs itself, without > > > knowing it, > > > and without HA. > > > > > > The current recommended migration flow is described in [2]. This page is > > > perhaps > > > a bit outdated, perhaps missing some details etc., but principally works. > > > The main > > > issue with it, AFAICT after discussing this a bit with few people, is > > > that > > > it > > > requires a new clean host. > > > > > > I'd like to hear what people here think about such and similar flows. > > > > > > If you already had an engine and migrated to hosted-engine, what was > > > good, > > > what > > > was bad, what would you like to change? > > > > > > If you plan such a migration, what do you find missing currently? > > > > > > [1] http://red.ht/1vle8Vv > > > [2] http://www.ovirt.org/Migrate_to_Hosted_Engine > > > > > > Best, > > > -- > > > Didi > > > ___ > > > Devel mailing list > > > de...@ovirt.org > > > http://lists.ovirt.org/mailman/listinfo/devel > > > > > > > -- > Didi > > ___ > Devel mailing list > de...@ovirt.org > http://lists.ovirt.org/mailman/listinfo/devel > Best, -- Didi ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Re: [ovirt-users] [ovirt-devel] hosted-engine setup/migration features for 3.6
- Original Message - > From: "Bob Doolittle" > To: "Yedidyah Bar David" > Sent: Wednesday, December 3, 2014 2:50:12 PM > Subject: Re: [ovirt-devel] hosted-engine setup/migration features for 3.6 > > Another issue with that page is that it assumes a remote database. I am not > sure what percentage of cases have remote databases but clearly many > (most?) do not, since that's not default behavior. I agree. > So that page definitely > needs attention. See: > https://bugzilla.redhat.com/show_bug.cgi?id=105 Indeed. Note that this isn't specific to hosted-engine, it's the same for any migration using engine-backup to backup/restore, therefore there is a link to its page in the top, where this is more detailed. We also have a bug [3] to automate this. [3] https://bugzilla.redhat.com/show_bug.cgi?id=1064503 > https://bugzilla.redhat.com/show_bug.cgi?id=108 > > Some of us have wanted to disable global maintenance upon bootup by adding > a systemd service on Fedora 20 (since you must enable global maintenance to > shut it down cleanly), and have found it impossible to create the necessary > systemd dependencies. It seems that (at least with 3.4) hosted-engine > --set-maintenance --mode=none will return an error for several seconds > after all other services have started and it's not clear what can be waited > upon in order to issue the command with assurance it will complete > successfully. This isn't strictly a setup/migration issue but it is an > issue with setting up a desired configuration with hosted-engine. The way > to reproduce this is simply to wait until gdm-greeter displays the login > prompt, ssh into the system and execute hosted-engine --set-maintenance > --mode=none and observe the error. Or create a systemd service that depends > upon (waits for) the latest-possible service, try executing the command > there, and observe the error. Ideally there would be some external > observable event which a systemd service could depend upon, when > hosted-engine is ready to do its thing. Adding Jiri for that. Do you have an open bug? Thanks, > > Regards, > Bob > > > On Wed, Dec 3, 2014 at 2:59 AM, Yedidyah Bar David wrote: > > > Hi all, > > > > We already have quite a lot of open ovirt-hosted-engine-setup bugs for 3.6 > > [1]. > > > > Yesterday I tried helping someone on irc who planned to migrate to > > hosted-engine > > manually, and without knowing (so it seems) that such a feature exists. He > > had > > an engine set up on a physical host, prepared a VM for it, and asked about > > migrating > > the engine to the VM. In principle this works, but the final result will > > be a > > hosted-engine, where the engine manages a VM the runs itself, without > > knowing it, > > and without HA. > > > > The current recommended migration flow is described in [2]. This page is > > perhaps > > a bit outdated, perhaps missing some details etc., but principally works. > > The main > > issue with it, AFAICT after discussing this a bit with few people, is that > > it > > requires a new clean host. > > > > I'd like to hear what people here think about such and similar flows. > > > > If you already had an engine and migrated to hosted-engine, what was good, > > what > > was bad, what would you like to change? > > > > If you plan such a migration, what do you find missing currently? > > > > [1] http://red.ht/1vle8Vv > > [2] http://www.ovirt.org/Migrate_to_Hosted_Engine > > > > Best, > > -- > > Didi > > ___ > > Devel mailing list > > de...@ovirt.org > > http://lists.ovirt.org/mailman/listinfo/devel > > > -- Didi ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Re: [ovirt-users] [ovirt-devel] hosted-engine setup/migration features for 3.6
Resending - inadvertently dropped CCs. On Wed, Dec 3, 2014 at 7:50 AM, Bob Doolittle wrote: > Another issue with that page is that it assumes a remote database. I am > not sure what percentage of cases have remote databases but clearly many > (most?) do not, since that's not default behavior. So that page definitely > needs attention. See: > https://bugzilla.redhat.com/show_bug.cgi?id=105 > https://bugzilla.redhat.com/show_bug.cgi?id=108 > > Some of us have wanted to disable global maintenance upon bootup by adding > a systemd service on Fedora 20 (since you must enable global maintenance to > shut it down cleanly), and have found it impossible to create the necessary > systemd dependencies. It seems that (at least with 3.4) hosted-engine > --set-maintenance --mode=none will return an error for several seconds > after all other services have started and it's not clear what can be waited > upon in order to issue the command with assurance it will complete > successfully. This isn't strictly a setup/migration issue but it is an > issue with setting up a desired configuration with hosted-engine. The way > to reproduce this is simply to wait until gdm-greeter displays the login > prompt, ssh into the system and execute hosted-engine --set-maintenance > --mode=none and observe the error. Or create a systemd service that depends > upon (waits for) the latest-possible service, try executing the command > there, and observe the error. Ideally there would be some external > observable event which a systemd service could depend upon, when > hosted-engine is ready to do its thing. > > Regards, > Bob > > > On Wed, Dec 3, 2014 at 2:59 AM, Yedidyah Bar David > wrote: > >> Hi all, >> >> We already have quite a lot of open ovirt-hosted-engine-setup bugs for >> 3.6 [1]. >> >> Yesterday I tried helping someone on irc who planned to migrate to >> hosted-engine >> manually, and without knowing (so it seems) that such a feature exists. >> He had >> an engine set up on a physical host, prepared a VM for it, and asked >> about migrating >> the engine to the VM. In principle this works, but the final result will >> be a >> hosted-engine, where the engine manages a VM the runs itself, without >> knowing it, >> and without HA. >> >> The current recommended migration flow is described in [2]. This page is >> perhaps >> a bit outdated, perhaps missing some details etc., but principally works. >> The main >> issue with it, AFAICT after discussing this a bit with few people, is >> that it >> requires a new clean host. >> >> I'd like to hear what people here think about such and similar flows. >> >> If you already had an engine and migrated to hosted-engine, what was >> good, what >> was bad, what would you like to change? >> >> If you plan such a migration, what do you find missing currently? >> >> [1] http://red.ht/1vle8Vv >> [2] http://www.ovirt.org/Migrate_to_Hosted_Engine >> >> Best, >> -- >> Didi >> ___ >> Devel mailing list >> de...@ovirt.org >> http://lists.ovirt.org/mailman/listinfo/devel >> > > ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
