jwcolby
jwcolby at colbyconsulting.com
Wed Mar 19 17:27:16 CDT 2008
I will try that. I am limited how far down I can go because the software that I run is a pretty big "in memory" database. John W. Colby Colby Consulting www.ColbyConsulting.com -----Original Message----- From: dba-tech-bounces at databaseadvisors.com [mailto:dba-tech-bounces at databaseadvisors.com] On Behalf Of Gustav Brock Sent: Wednesday, March 19, 2008 6:15 PM To: dba-tech at databaseadvisors.com Subject: Re: [dba-Tech] VMWare VM and shared RAMDISK Hi John That sounds likely. But how about adjusting down the ram use for each machine - just for a test. /gustav >>> jwcolby at colbyconsulting.com 19-03-2008 20:51 >>> It appears that when I start the second machine it hits the swap file a lot or something. These machines are each 2.X gigs of memory and need to be in order to run the process I am trying to run. The first one continues to run full speed but the second runs very slowly. One reason that I think the swap file may be involved is that the VM setup warns against setting up a vm with more than 3.X gigs of ram "or it will use the swap file and performance will suffer". I am guessing that the COMBINED memory for the two vms is exceeding this value and so the second machine started runs slowly. Just a guess though. Something is going wrong. That is in addition to the issue of the vm reboot though. The vm reboot appears to be something to do with both trying to run virtual disks where the vd files are on the same hardware ram disk. That too is just a guess. I don't really know enough to figure out how to figure out the causes of things like this, other than experimentation. John W. Colby Colby Consulting www.ColbyConsulting.com -----Original Message----- From: dba-tech-bounces at databaseadvisors.com [mailto:dba-tech-bounces at databaseadvisors.com] On Behalf Of Gustav Brock Sent: Wednesday, March 19, 2008 12:58 PM To: dba-tech at databaseadvisors.com Subject: Re: [dba-Tech] VMWare VM and shared RAMDISK Hi John Two instances of "the same" machine can easily run. I have had three web servers running in parallel. However, they must - of course - be configured to use different disk(file)s ... /gustav >>> jwcolby at colbyconsulting.com 19-03-2008 17:50 >>> I got two instances of the same virtual machine going this morning. A simple copy of the directory is mostly all that has to be done. There is some sort of machine ID which VMWare complains is duplicated when the second instance fires up, let VMWare correct that and then as the second instance starts it says there are two machines with the same name on the network. That required just setting the machine name to be different from the first and rebooting that VM. However the second machine will not run the software at the same time as the first. I set up virtual disks from the VM supervisor, one for each VM. Each is a file on the hardware ram disk in the VMWare host machine. I can set them up, format them etc but when the second VM starts to run it eventually reboots. I am guessing that it is a conflict with the SATA controller (when accessing the RAM disk) or some such. It doesn't matter, at this point I simply cannot run the second VM and have both access their respective virtual drives on the Hardware RAM disk. Sigh. I guess that is why we do testing eh? John W. Colby Colby Consulting www.ColbyConsulting.com _______________________________________________ dba-Tech mailing list dba-Tech at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/dba-tech Website: http://www.databaseadvisors.com