[Users] how to convince oVirt a VM is down
One of my hosts died while going into maintenance mode. 2 of the VMs didn't make it through migration before it became unresponsive. Now, they are flagged as unknown and I can't do anything with them in that state. I can't even remove them? Anyway, is there anyway to convince the engine that a VM is down so I can bring it back up again, like with "Confirm 'host has been rebooted'" on hosts? _______________ Alan Johnson alan@datdec.com
On 10/09/2012 09:23 PM, Alan Johnson wrote:
One of my hosts died while going into maintenance mode. 2 of the VMs didn't make it through migration before it became unresponsive. Now, they are flagged as unknown and I can't do anything with them in that state. I can't even remove them?
Anyway, is there anyway to convince the engine that a VM is down so I can bring it back up again, like with "Confirm 'host has been rebooted'" on hosts?
which hosts are they supposedly on? does 'confirm host shutdown' on the host not release them?
On Tue, Oct 9, 2012 at 3:49 PM, Itamar Heim <iheim@redhat.com> wrote:
On 10/09/2012 09:23 PM, Alan Johnson wrote:
Anyway, is there anyway to convince the engine that a VM is down so I can bring it back up again, like with "Confirm 'host has been rebooted'" on hosts?
which hosts are they supposedly on?
The host column is blank for these VMs. Also, running `virsh --readonly list` on the remaining hosts matches the VMs oVirt shows as running and does not list the "Unknown" VMs on either host.
does 'confirm host shutdown' on the host not release them?
It did not. I also removed the host since I will need to add it back in after re-installing the OS on a more stable boot drive. Still no change. You have me thinking... perhaps oVirt thinks they are running on the host they were being migrated to. If so, maybe putting that host into maintenance will clear it up. I'll try that as soon as I get the down host back up.
On Tue, Oct 9, 2012 at 4:01 PM, Alan Johnson <alan@datdec.com> wrote:
You have me thinking... perhaps oVirt thinks they are running on the host they were being migrated to. If so, maybe putting that host into maintenance will clear it up. I'll try that as soon as I get the down host back up.
Nope, the 2 stuck VMs have still not been released from "Unknown" status. I've rebooted the 3rd host and restarted the engine. Still no love. Please help.
On 10/09/2012 11:19 PM, Alan Johnson wrote:
On Tue, Oct 9, 2012 at 4:01 PM, Alan Johnson <alan@datdec.com <mailto:alan@datdec.com>> wrote:
You have me thinking... perhaps oVirt thinks they are running on the host they were being migrated to. If so, maybe putting that host into maintenance will clear it up. I'll try that as soon as I get the down host back up.
Nope, the 2 stuck VMs have still not been released from "Unknown" status. I've rebooted the 3rd host and restarted the engine. Still no love. Please help.
well, hacking the db will work, but reproducing this and logs for us to fix the actually bug would also help.
On 10/09/2012 11:36 PM, Itamar Heim wrote:
On 10/09/2012 11:19 PM, Alan Johnson wrote:
On Tue, Oct 9, 2012 at 4:01 PM, Alan Johnson <alan@datdec.com <mailto:alan@datdec.com>> wrote:
You have me thinking... perhaps oVirt thinks they are running on the host they were being migrated to. If so, maybe putting that host into maintenance will clear it up. I'll try that as soon as I get the down host back up.
Nope, the 2 stuck VMs have still not been released from "Unknown" status. I've rebooted the 3rd host and restarted the engine. Still no love. Please help.
well, hacking the db will work, but reproducing this and logs for us to fix the actually bug would also help.
We have seen this before, and we thought it was fixed. Alan, can you describe exactly the sequence of events that leaded to this problem? When you say that the host died while going to maintenance what do you mean exactly? It crashed, rebooted, hung, was fenced? It would be very helpful if you have the engine logs at the time the host went down. Once you have those logs in a safe place, the only way to get the VM out of that status is to update the database manually. First make completely sure that the VM is not running in any host, then do the following: # psql -U engine psql (9.1.6) Type "help" for help. engine=> update vm_dynamic set status = 0 where vm_guid = (select vm_gui from vm_static where vm_name = 'myvm'); UPDATE 1 (Assuming that the name of your VM is "myvm"). -- Dirección Comercial: C/Jose Bardasano Baos, 9, Edif. Gorbea 3, planta 3ºD, 28016 Madrid, Spain Inscrita en el Reg. Mercantil de Madrid – C.I.F. B82657941 - Red Hat S.L.
On Wed, Oct 10, 2012 at 4:35 AM, Juan Hernandez <jhernand@redhat.com> wrote:
On 10/09/2012 11:36 PM, Itamar Heim wrote:
well, hacking the db will work, but reproducing this and logs for us to fix the actually bug would also help.
Unfortunately, it will would be very difficult to reproduce since I have replaced the boot drive that I believe was causing the failures and I have no idea what state the host was in when it went down (details below). Plus, our testing folks will become very angry if I keep crashing their VMs. =) Still, I can probably come up with some spare hardware eventually and try to reproduce if needed, but let's see what we see with the logs, etc., first, yeah?
We have seen this before, and we thought it was fixed.
Was that very recently? Perhaps I was not running the fixed version. I might not be still. I'm running on CentOS 6.3 using this repo: http://www.dreyou.org/ovirt/ovirt-dre.repo I used these instructions to setup the nodes<http://middleswarth.net/content/installing-ovirt-31-and-glusterfs-using-either-nfs-or-posix-native-file-system-node-install> and these instructions to setup the engine<http://middleswarth.net/content/installing-ovirt-31-and-glusterfs-using-either-nfs-or-posix-native-file-system-engine>. (I have not configured any glusterfs volumes, but I will likely play with that soon.) When setting up the engine, I had to fix a bunch of broken symlinks to jar files that were included with the various packages. Both the broken symlinks and jar files there there, but many of the symlinks to the jars where broken. I'll be reporting that to the package maintainers soon, but mention it here just in case it turns out to be relevant. Here are my ovirt package versions: [root@admin ~]# rpm -qa | fgrep -i ovirt ovirt-log-collector-3.1.0-16.el6.noarch ovirt-image-uploader-3.1.0-16.el6.noarch ovirt-engine-userportal-3.1.0-3.19.el6.noarch ovirt-engine-setup-3.1.0-3.19.el6.noarch ovirt-engine-restapi-3.1.0-3.19.el6.noarch ovirt-engine-config-3.1.0-3.19.el6.noarch ovirt-engine-notification-service-3.1.0-3.19.el6.noarch ovirt-engine-backend-3.1.0-3.19.el6.noarch ovirt-engine-sdk-3.1.0.5-1.el6.noarch ovirt-iso-uploader-3.1.0-16.el6.noarch ovirt-engine-jbossas711-1-0.x86_64 ovirt-engine-webadmin-portal-3.1.0-3.19.el6.noarch ovirt-engine-dbscripts-3.1.0-3.19.el6.noarch ovirt-engine-genericapi-3.1.0-3.19.el6.noarch ovirt-engine-tools-common-3.1.0-3.19.el6.noarch ovirt-engine-3.1.0-3.19.el6.noarch [root@cloudhost03 ~]# rpm -qa | fgrep -i vdsm vdsm-xmlrpc-4.10.0-0.42.13.el6.noarch vdsm-gluster-4.10.0-0.42.13.el6.noarch vdsm-python-4.10.0-0.42.13.el6.x86_64 vdsm-4.10.0-0.42.13.el6.x86_64 vdsm-cli-4.10.0-0.42.13.el6.noarch
Alan, can you describe exactly the sequence of events that leaded to this problem? When you say that the host died while going to maintenance
what do you mean exactly? It crashed, rebooted, hung, was fenced? I'll do my best. =) First, some back ground. I have 3 hosts in oVirt currently: cloudhost0{2,3,4}. (1 out there but not in oVirt just yet, so of no consequence. It is currently running the VM hosting oVirt engine, but I doubt that is relevant either.) I originally build these using USB sticks as the boot drives hoping to leave the drive bays dedicated to VM storage. I bought what seemed to be the best ones for the jobs, but the root file system kept started going into read-only due to device errors recently. It only happened once before I installed oVirt a few weeks ago, but I brough to new hosts on line with oVirt, so maybe I was just lucky with the first 2 hosts. After converting to oVirt, the USB drives starting going read-only more often and I think they might not have been fast enough to keep up with the write requests from a host OS running a full load of VMs (~10), causing performance problems with some of our VMs. So, I started replacing the USB drives putting one host into maintenance at a time. I started with cloudhost04 not because it had gone read-only, but in hopes of improving performance. While it was migrating VMs for maintenance mode, the engine marked it in an unknown state. vdsmd had crashed and would not start because it could not write logs or pid files. The / mount had gone ro. I'm not 100% sure now, but I think a couple of VMs were successfully migrated, but several were not. libvirtd was up and the VMs were none the wiser, but I could not figure out the virsh password to tell it to migrate VMs despite finding a thread in this list with some pointers. So, we logged into each VM and shut them down manually. Once virsh listed no running VMs, I shut down clh04, Confirm 'Host has been Rebooted', in the GUI, and the engine let me start the VMs on another host. (I.e., they went from status "unknown" to status "down".) I yanked the USB drive, removed the host from in the GUI, and then rebuilt the node on a SATA SSD using the instructions linked above. All has been fine with that node since. I follow the same procedure on cloudhost03 with no trouble at all. It went into maintenance mode without a hitch. Now, for the case in question. I put cloudhost02 into maintenance mode and went to lunch. After lunch and some other distractions, I found it successfully migrated all but 2 of the VMs to other nodes before becoming unresponsive. Unlike cloudhost04, which I could ssh into and manipulate, 02 had become completely unresponsive Even the console was just a black screen with not response to mouse or keyboard. The rest is covered previously in this thread. In short, no amount of node rebooting, confirming host reboots, engine restarting, or removing and adding hosts back in convinced the engine to take the VMs out of unknown status. Also, the host column was blank for the entire time they were in unknown status, as far as I know. (In case anyone is curious, I have had no confirmation on performance improvements since converting all nodes to SSD boot drives, but I have had no complaints since either.)
It would be very helpful if you have the engine logs at the time the host went down.
Attached. Also, I have the USB stick from cloudhost02, so if there are logs on there that might help, just point me to them. The migration started around 2012-10-09 12:36:28. I started fighting with it again after 2PM.
Once you have those logs in a safe place, the only way to get the VM out of that status is to update the database manually. First make completely sure that the VM is not running in any host, then do the following:
# psql -U engine psql (9.1.6) Type "help" for help.
engine=> update vm_dynamic set status = 0 where vm_guid = (select vm_gui from vm_static where vm_name = 'myvm'); UPDATE 1
(Assuming that the name of your VM is "myvm").
That did the trick! Thank you so much, Juan! I had to fix a typo by changing 'vm_gui' to 'vm_guid' after 'select', but the error from the first try made that clear. Regardless, it was all I needed. Here is the corrected syntax all on one line for others that may be looking for the same fix: engine=> update vm_dynamic set status = 0 where vm_guid = (select vm_guid from vm_static where vm_name = 'myvm');
This is a multi-part message in MIME format. --------------080207050007090000030901 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit since the VM run_on_vds was empty, the "confirm host..." didn't clear its status because its not selected from the DB as one of the host VMs. I'll try to dig in to see at what point this value was cleared - probably around the failed migration. On 10/10/2012 07:25 PM, Alan Johnson wrote:
On Wed, Oct 10, 2012 at 4:35 AM, Juan Hernandez <jhernand@redhat.com <mailto:jhernand@redhat.com>> wrote:
On 10/09/2012 11:36 PM, Itamar Heim wrote: > well, hacking the db will work, but reproducing this and logs for us to > fix the actually bug would also help.
Unfortunately, it will would be very difficult to reproduce since I have replaced the boot drive that I believe was causing the failures and I have no idea what state the host was in when it went down (details below). Plus, our testing folks will become very angry if I keep crashing their VMs. =) Still, I can probably come up with some spare hardware eventually and try to reproduce if needed, but let's see what we see with the logs, etc., first, yeah?
We have seen this before, and we thought it was fixed.
Was that very recently? Perhaps I was not running the fixed version. I might not be still. I'm running on CentOS 6.3 using this repo: http://www.dreyou.org/ovirt/ovirt-dre.repo
I used these instructions to setup the nodes <http://middleswarth.net/content/installing-ovirt-31-and-glusterfs-using-either-nfs-or-posix-native-file-system-node-install> and these instructions to setup the engine <http://middleswarth.net/content/installing-ovirt-31-and-glusterfs-using-either-nfs-or-posix-native-file-system-engine>. (I have not configured any glusterfs volumes, but I will likely play with that soon.) When setting up the engine, I had to fix a bunch of broken symlinks to jar files that were included with the various packages. Both the broken symlinks and jar files there there, but many of the symlinks to the jars where broken. I'll be reporting that to the package maintainers soon, but mention it here just in case it turns out to be relevant.
Here are my ovirt package versions: [root@admin ~]# rpm -qa | fgrep -i ovirt ovirt-log-collector-3.1.0-16.el6.noarch ovirt-image-uploader-3.1.0-16.el6.noarch ovirt-engine-userportal-3.1.0-3.19.el6.noarch ovirt-engine-setup-3.1.0-3.19.el6.noarch ovirt-engine-restapi-3.1.0-3.19.el6.noarch ovirt-engine-config-3.1.0-3.19.el6.noarch ovirt-engine-notification-service-3.1.0-3.19.el6.noarch ovirt-engine-backend-3.1.0-3.19.el6.noarch ovirt-engine-sdk-3.1.0.5-1.el6.noarch ovirt-iso-uploader-3.1.0-16.el6.noarch ovirt-engine-jbossas711-1-0.x86_64 ovirt-engine-webadmin-portal-3.1.0-3.19.el6.noarch ovirt-engine-dbscripts-3.1.0-3.19.el6.noarch ovirt-engine-genericapi-3.1.0-3.19.el6.noarch ovirt-engine-tools-common-3.1.0-3.19.el6.noarch ovirt-engine-3.1.0-3.19.el6.noarch
[root@cloudhost03 ~]# rpm -qa | fgrep -i vdsm vdsm-xmlrpc-4.10.0-0.42.13.el6.noarch vdsm-gluster-4.10.0-0.42.13.el6.noarch vdsm-python-4.10.0-0.42.13.el6.x86_64 vdsm-4.10.0-0.42.13.el6.x86_64 vdsm-cli-4.10.0-0.42.13.el6.noarch
Alan, can you describe exactly the sequence of events that leaded to this problem? When you say that the host died while going to maintenance
what do you mean exactly? It crashed, rebooted, hung, was fenced?
I'll do my best. =) First, some back ground. I have 3 hosts in oVirt currently: cloudhost0{2,3,4}. (1 out there but not in oVirt just yet, so of no consequence. It is currently running the VM hosting oVirt engine, but I doubt that is relevant either.) I originally build these using USB sticks as the boot drives hoping to leave the drive bays dedicated to VM storage. I bought what seemed to be the best ones for the jobs, but the root file system kept started going into read-only due to device errors recently. It only happened once before I installed oVirt a few weeks ago, but I brough to new hosts on line with oVirt, so maybe I was just lucky with the first 2 hosts.
After converting to oVirt, the USB drives starting going read-only more often and I think they might not have been fast enough to keep up with the write requests from a host OS running a full load of VMs (~10), causing performance problems with some of our VMs. So, I started replacing the USB drives putting one host into maintenance at a time.
I started with cloudhost04 not because it had gone read-only, but in hopes of improving performance. While it was migrating VMs for maintenance mode, the engine marked it in an unknown state. vdsmd had crashed and would not start because it could not write logs or pid files. The / mount had gone ro.
I'm not 100% sure now, but I think a couple of VMs were successfully migrated, but several were not. libvirtd was up and the VMs were none the wiser, but I could not figure out the virsh password to tell it to migrate VMs despite finding a thread in this list with some pointers. So, we logged into each VM and shut them down manually. Once virsh listed no running VMs, I shut down clh04, Confirm 'Host has been Rebooted', in the GUI, and the engine let me start the VMs on another host. (I.e., they went from status "unknown" to status "down".)
I yanked the USB drive, removed the host from in the GUI, and then rebuilt the node on a SATA SSD using the instructions linked above. All has been fine with that node since. I follow the same procedure on cloudhost03 with no trouble at all. It went into maintenance mode without a hitch.
Now, for the case in question. I put cloudhost02 into maintenance mode and went to lunch. After lunch and some other distractions, I found it successfully migrated all but 2 of the VMs to other nodes before becoming unresponsive. Unlike cloudhost04, which I could ssh into and manipulate, 02 had become completely unresponsive Even the console was just a black screen with not response to mouse or keyboard. The rest is covered previously in this thread. In short, no amount of node rebooting, confirming host reboots, engine restarting, or removing and adding hosts back in convinced the engine to take the VMs out of unknown status. Also, the host column was blank for the entire time they were in unknown status, as far as I know.
(In case anyone is curious, I have had no confirmation on performance improvements since converting all nodes to SSD boot drives, but I have had no complaints since either.)
It would be very helpful if you have the engine logs at the time the host went down.
Attached. Also, I have the USB stick from cloudhost02, so if there are logs on there that might help, just point me to them. The migration started around 2012-10-09 12:36:28. I started fighting with it again after 2PM.
Once you have those logs in a safe place, the only way to get the VM out of that status is to update the database manually. First make completely sure that the VM is not running in any host, then do the following:
# psql -U engine psql (9.1.6) Type "help" for help.
engine=> update vm_dynamic set status = 0 where vm_guid = (select vm_gui from vm_static where vm_name = 'myvm'); UPDATE 1
(Assuming that the name of your VM is "myvm").
That did the trick! Thank you so much, Juan! I had to fix a typo by changing 'vm_gui' to 'vm_guid' after 'select', but the error from the first try made that clear. Regardless, it was all I needed. Here is the corrected syntax all on one line for others that may be looking for the same fix:
engine=> update vm_dynamic set status = 0 where vm_guid = (select vm_guid from vm_static where vm_name = 'myvm');
_______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
--------------080207050007090000030901 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit <html> <head> <meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"> </head> <body bgcolor="#FFFFFF" text="#000000"> <div class="moz-cite-prefix"><br> since the VM run_on_vds was empty, the "confirm host..." didn't clear its status because its not selected from the DB as one of the host VMs. <br> I'll try to dig in to see at what point this value was cleared - probably around the failed migration.<br> <br> <br> On 10/10/2012 07:25 PM, Alan Johnson wrote:<br> </div> <blockquote cite="mid:CAAhwQij0zfoxwO0hzywG_bWTNs+VbCw7KTQyrk+Vbqy2UNNRmQ@mail.gmail.com" type="cite">On Wed, Oct 10, 2012 at 4:35 AM, Juan Hernandez <span dir="ltr"><<a moz-do-not-send="true" href="mailto:jhernand@redhat.com" target="_blank">jhernand@redhat.com</a>></span> wrote:<br> <div class="gmail_quote"> <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> <div class="HOEnZb"> <div class="h5">On 10/09/2012 11:36 PM, Itamar Heim wrote:<br> > well, hacking the db will work, but reproducing this and logs for us to<br> > fix the actually bug would also help.<br> </div> </div> </blockquote> <div><br> </div> <div>Unfortunately, it will would be very difficult to reproduce since I have replaced the boot drive that I believe was causing the failures and I have no idea what state the host was in when it went down (details below). Plus, our testing folks will become very angry if I keep crashing their VMs. =) Still, I can probably come up with some spare hardware eventually and try to reproduce if needed, but let's see what we see with the logs, etc., first, yeah?</div> <div> </div> <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> <div class="HOEnZb"> <div class="h5"> <br> </div> </div> We have seen this before, and we thought it was fixed.<br> </blockquote> <div><br> </div> <div>Was that very recently? Perhaps I was not running the fixed version. I might not be still. I'm running on CentOS 6.3 using this repo: <a moz-do-not-send="true" href="http://www.dreyou.org/ovirt/ovirt-dre.repo">http://www.dreyou.org/ovirt/ovirt-dre.repo</a></div> <div><br> </div> <div>I used these <a moz-do-not-send="true" href="http://middleswarth.net/content/installing-ovirt-31-and-glusterfs-using-either-nfs-or-posix-native-file-system-node-install">instructions to setup the nodes</a> and these <a moz-do-not-send="true" href="http://middleswarth.net/content/installing-ovirt-31-and-glusterfs-using-either-nfs-or-posix-native-file-system-engine">instructions to setup the engine</a>. (I have not configured any glusterfs volumes, but I will likely play with that soon.) When setting up the engine, I had to fix a bunch of broken symlinks to jar files that were included with the various packages. Both the broken symlinks and jar files there there, but many of the symlinks to the jars where broken. I'll be reporting that to the package maintainers soon, but mention it here just in case it turns out to be relevant.</div> <div><br> </div> <div>Here are my ovirt package versions:</div> <div> <div><font face="courier new, monospace">[root@admin ~]# rpm -qa | fgrep -i ovirt</font></div> <div><font face="courier new, monospace">ovirt-log-collector-3.1.0-16.el6.noarch</font></div> <div><font face="courier new, monospace">ovirt-image-uploader-3.1.0-16.el6.noarch</font></div> <div><font face="courier new, monospace">ovirt-engine-userportal-3.1.0-3.19.el6.noarch</font></div> <div><font face="courier new, monospace">ovirt-engine-setup-3.1.0-3.19.el6.noarch</font></div> <div><font face="courier new, monospace">ovirt-engine-restapi-3.1.0-3.19.el6.noarch</font></div> <div><font face="courier new, monospace">ovirt-engine-config-3.1.0-3.19.el6.noarch</font></div> <div><font face="courier new, monospace">ovirt-engine-notification-service-3.1.0-3.19.el6.noarch</font></div> <div><font face="courier new, monospace">ovirt-engine-backend-3.1.0-3.19.el6.noarch</font></div> <div><font face="courier new, monospace">ovirt-engine-sdk-3.1.0.5-1.el6.noarch</font></div> <div><font face="courier new, monospace">ovirt-iso-uploader-3.1.0-16.el6.noarch</font></div> <div><font face="courier new, monospace">ovirt-engine-jbossas711-1-0.x86_64</font></div> <div><font face="courier new, monospace">ovirt-engine-webadmin-portal-3.1.0-3.19.el6.noarch</font></div> <div><font face="courier new, monospace">ovirt-engine-dbscripts-3.1.0-3.19.el6.noarch</font></div> <div><font face="courier new, monospace">ovirt-engine-genericapi-3.1.0-3.19.el6.noarch</font></div> <div><font face="courier new, monospace">ovirt-engine-tools-common-3.1.0-3.19.el6.noarch</font></div> <div><font face="courier new, monospace">ovirt-engine-3.1.0-3.19.el6.noarch</font></div> </div> <div><font face="courier new, monospace"><br> </font></div> <div> <div><font face="courier new, monospace">[root@cloudhost03 ~]# rpm -qa | fgrep -i vdsm</font></div> <div><font face="courier new, monospace">vdsm-xmlrpc-4.10.0-0.42.13.el6.noarch</font></div> <div><font face="courier new, monospace">vdsm-gluster-4.10.0-0.42.13.el6.noarch</font></div> <div><font face="courier new, monospace">vdsm-python-4.10.0-0.42.13.el6.x86_64</font></div> <div><font face="courier new, monospace">vdsm-4.10.0-0.42.13.el6.x86_64</font></div> <div><font face="courier new, monospace">vdsm-cli-4.10.0-0.42.13.el6.noarch</font></div> </div> <div><br> </div> <div> </div> <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> <br> Alan, can you describe exactly the sequence of events that leaded to<br> this problem? When you say that the host died while going to maintenance</blockquote> <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> what do you mean exactly? It crashed, rebooted, hung, was fenced? </blockquote> <div><br> </div> <div> <div>I'll do my best. =) First, some back ground. I have 3 hosts in oVirt currently: cloudhost0{2,3,4}. (1 out there but not in oVirt just yet, so of no consequence. It is currently running the VM hosting oVirt engine, but I doubt that is relevant either.) I originally build these using USB sticks as the boot drives hoping to leave the drive bays dedicated to VM storage. I bought what seemed to be the best ones for the jobs, but the root file system kept started going into read-only due to device errors recently. It only happened once before I installed oVirt a few weeks ago, but I brough to new hosts on line with oVirt, so maybe I was just lucky with the first 2 hosts.</div> <div><br> </div> <div>After converting to oVirt, the USB drives starting going read-only more often and I think they might not have been fast enough to keep up with the write requests from a host OS running a full load of VMs (~10), causing performance problems with some of our VMs. So, I started replacing the USB drives putting one host into maintenance at a time.</div> </div> <div><br> </div> <div>I started with cloudhost04 not because it had gone read-only, but in hopes of improving performance. While it was migrating VMs for maintenance mode, the engine marked it in an unknown state. vdsmd had crashed and would not start because it could not write logs or pid files. The / mount had gone ro. </div> <div><br> </div> <div>I'm not 100% sure now, but I think a couple of VMs were successfully migrated, but several were not. libvirtd was up and the VMs were none the wiser, but I could not figure out the virsh password to tell it to migrate VMs despite finding a thread in this list with some pointers. So, we logged into each VM and shut them down manually. Once virsh listed no running VMs, I shut down clh04, Confirm 'Host has been Rebooted', in the GUI, and the engine let me start the VMs on another host. (I.e., they went from status "unknown" to status "down".)</div> <div><br> </div> <div>I yanked the USB drive, removed the host from in the GUI, and then rebuilt the node on a SATA SSD using the instructions linked above. All has been fine with that node since. I follow the same procedure on cloudhost03 with no trouble at all. It went into maintenance mode without a hitch.</div> <div><br> </div> <div>Now, for the case in question. I put cloudhost02 into maintenance mode and went to lunch. After lunch and some other distractions, I found it successfully migrated all but 2 of the VMs to other nodes before becoming unresponsive. Unlike cloudhost04, which I could ssh into and manipulate, 02 had become completely unresponsive Even the console was just a black screen with not response to mouse or keyboard. The rest is covered previously in this thread. In short, no amount of node rebooting, confirming host reboots, engine restarting, or removing and adding hosts back in convinced the engine to take the VMs out of unknown status. Also, the host column was blank for the entire time they were in unknown status, as far as I know.</div> <div><br> </div> <div>(In case anyone is curious, I have had no confirmation on performance improvements since converting all nodes to SSD boot drives, but I have had no complaints since either.)</div> <div> </div> <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> It would be very helpful if you have the engine logs at the time the host<br> went down.<br> </blockquote> <div><br> </div> <div>Attached. Also, I have the USB stick from cloudhost02, so if there are logs on there that might help, just point me to them. The migration started around 2012-10-09 12:36:28. I started fighting with it again after 2PM.</div> <div> </div> <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> <br> Once you have those logs in a safe place, the only way to get the VM out<br> of that status is to update the database manually. First make completely<br> sure that the VM is not running in any host, then do the following:<br> <br> # psql -U engine<br> psql (9.1.6)<br> Type "help" for help.<br> <br> engine=> update vm_dynamic set status = 0 where vm_guid = (select<br> vm_gui from vm_static where vm_name = 'myvm');<br> UPDATE 1<br> <br> (Assuming that the name of your VM is "myvm").<br> </blockquote> <div><br> </div> <div>That did the trick! Thank you so much, Juan! I had to fix a typo by changing 'vm_gui' to 'vm_guid' after 'select', but the error from the first try made that clear. Regardless, it was all I needed. Here is the corrected syntax all on one line for others that may be looking for the same fix:</div> <div><br> </div> <div>engine=> update vm_dynamic set status = 0 where vm_guid = (select vm_guid from vm_static where vm_name = 'myvm');</div> <div><br> </div> </div> <br> <fieldset class="mimeAttachmentHeader"></fieldset> <br> <pre wrap="">_______________________________________________ Users mailing list <a class="moz-txt-link-abbreviated" href="mailto:Users@ovirt.org">Users@ovirt.org</a> <a class="moz-txt-link-freetext" href="http://lists.ovirt.org/mailman/listinfo/users">http://lists.ovirt.org/mailman/listinfo/users</a></pre> </blockquote> <br> </body> </html> --------------080207050007090000030901--
On Thu, Oct 11, 2012 at 3:20 AM, Roy Golan <rgolan@redhat.com> wrote:
since the VM run_on_vds was empty, the "confirm host..." didn't clear its status because its not selected from the DB as one of the host VMs. I'll try to dig in to see at what point this value was cleared - probably around the failed migration.
Cool. Let me know if you need anything else from me. Again, I have the USB stick from cloudhost02 when it failed, if there is a log for vdsmd or something that might have something useful in it, just send me the path. Are transactions in use in the system anywhere, either in the DB or the app layer? If not, have they been considered? I ask because this seems like the kind of thing they would address nicely. Specifically, if migration recipient is up and happy, but does not confirm VM is up or migration in progress, and sender node is no longer responsive, roll back to assuming the VM is still running on sender. This would avoid the inconsistent state I had of not-down-but-not-running-on-any-responding-host either and allow "confirm host..." to clear the unknown state of the VM. Sorry if I am stating the obvious or over simplifying. It has been a long time since I wrote any significant code. =)
participants (4)
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Alan Johnson -
Itamar Heim -
Juan Hernandez -
Roy Golan