Bits and pieces ive come across using VMWare ESX 3, 3.5i and 4i along with vCentre and vSphere etc..
Posted by admin on August 18th, 2010 |
0 comments
We recently encountered a problem which nearly ground our VMWare ESX farm to a halt.
The cause of the problem was a iscsi lock caused by 2 hosts trying to write to the same store at the same time.
This was evident from messages on the ESX hosts from the error message: vprob.vmfs.heartbeat.timedout and referencing one of the volumes on our ISCSI storage.
This was causing the entire ESX host to have connectivity problems as well as affecting the guests that resided on that volume.
Because the host and guests were not accesible through vSphere, we were unable to remove the volume or power cycle the guests.
After much digging around and with the help of VMWare support we understood that the cause of the problem was a lock on that filesystem, and to fix the problem we ran vmkfstools -L lunreset /vmfs/devices/disks/volumename…
This removed the lock which was caused by 2 hosts trying to write to the same volume at the same time and causing a iscsi lock.
Very painful, but happy to have the cluster back up and running.
Posted by admin on August 4th, 2010 |
0 commentsPerhaps everyone knows this, but its not something I have come across before.
I recently built a fedora 13 server without any of the X / Gnome / KDE parts as I only want command line on it – this is relativly normal for what I do, however I normally use kickstart scripts, but as it was my first jaunt into 13 I didnt.
Its common for me to set up interface aliases as I use apache and a number of sites with SSL which requires independant IP addresses.
Normally I create a interface aliase file in /etc/sysconfig/network-scripts to the figure of ifcfg-eth0:0 etc..
Doing this in FC13 and then trying to bring the interface up threw up the following error
Bringing up interface eth0:
** (process:3898): WARNING **: fetch_connections_done: error fetching user connections: (2) The name org.freedesktop.NetworkManagerUserSettings was not provided by any .service files.
Bringing up interface eth0: ** (process:3898): WARNING **: fetch_connections_done: error fetching user connections: (2) The name org.freedesktop.NetworkManagerUserSettings was not provided by any .service files.
As I mentioned I have configured aliases lots so was confused as to exactly what was causing my problem – however the clue was in the error message – as it normally is..
The NetworkManager service was running which I dont use and this was preventing my alias’s from working properly. So a quick pkill -9 NetworkManager and then removing it from rc3.d to stop it starting up again fixed all my issues.
I guess thats what happens when you script build all the time – you forget these little bits 
Posted by admin on July 8th, 2010 |
0 commentsBack in the (good?) old days, it was easy to change the user IIS ran as through the services console you could pick anyone you wanted.
You might need to do this for a variety of reasons, access to remote services, file systems or for other reasons.
However with windows 2008 and IIS 7 / 7.5 you can no longer run the World Wide Web service as a different user without a whole world of pain..
For most people there is a fairly simple way to resolve this – in IIS 7.5 now the ApplicationPools are what fire up the specific workers for the w3wp process, and as such its very simple to change the user that the w3wp process runs as.
Open IIS management console and expand your website tree.
Click on Application Pools, and in the right hand pane you should see the DefaultAppPool – you will also see the user or Identidy that this is currently running as.
To change this to a different user simply right click the DefaultAppPool and select Advanced settings, then under the process model section click the identity name and click the elipses (the 3 dots) you will then be prompted which user account you wish to use.
If you want to use IIS to pass authentication through to a non domain machine then still in advanced settings you will also need to change the option for LoadProfile to true – this allows you to pull the credentials that get cached in cmdkey should you need it (see my other post on cmdkey).
Once you have done this, right click the DefaultAppPool and choose recycle for good measure which restarts the w3wp process.
You should now see it in task manager process list running as your defined user, and hopefully have access to all the resources you needed.