by Duncan Epping
A couple of weeks ago I received a cool PDF via email, this week it appeared online(source blog). Check it out:
The Source PDF:
VMware has collaborated with Cisco to produce a guide for deploying VMware Infrastucture 3 with Cisco switches. This guide covers the physical and virtual data network and storage network deployment considerations for ESX Server with suggested topologies and designs.
Just noticed the following topic, which definitely contains some good info about how ESX deals with memory. Thanks to Kit for clearing things up. These posts are valuable, keep ’em coming!
a short outtake:
Basically how aggressive do you want TPS to scan for shared pages? Obviously TPS has a cost to running in terms of CPU, but has benefits in terms of reduced memory usage. So there’s a tradeoff. We have a default that we think is a good balance, but we let the user modify that if they want.
Just dropped the following short script in a topic on the VMTN Community. It shuts down every VM on the host and than the host itself, but it will enter maintenance mode first, just to be sure that no other vm’s get migrated to this host.
VMLIST=’vmware-cmd -l’
for config in ${VMLIST}
do
vmware-cmd $config stop trysoft
done
vimsh -n -e /hostsvc/maintenance_mode_enter
shutdown -h now
addition: thanks forbes for the trysoft addition.
At a customer site we noticed that the ESX hosts were swapping, Nagios generated a nice alarm. After some research it seemed like certain VM’s were swapping to the VMFS volume, so not inside the OS but VMware swap usage. A closer look at the system revealed that we weren’t overcommitting. There was over 6GB of memory free and there were no limit’s set to the specific VM. Could it be just Nagios or… No, esxtop with the following commands “s2
The column swcur displays the current swap file usage, I marked the values higher than 0 red.
After a couple of searches it seemed that there is little info about swcur. But Kit Colbert, a VMware employee, posted on the vmtn forum about checking your current memory / swap usage in the file “/proc/vmware/sched/mem”. With cat you can easily display this, and with “watch -n 1” you can refresh your view every second. The following output was retrieved via the command “watch -n 1 cat /proc/vmware/sched/mem”:
We’ve migrated a VM which was swapping according to esxtop and nagios to another host, and as expected the swap remained. We powered down a VM that was swapping, and although the host had more than enough free mem available, the swap returned. It was less than before but still… The funny thing is that according to Kit it’s all about the column “swap out” and we did not see much action going on there.
I’m dazzled, anyone?
A while back I blogged about the customization specification wizard failing when entering the password. Today I visited the same customer again. This problem only occurred when running it from the VirtualCenter itself. Today I upgraded the VirtualCenter server to 2.5 Update 1 and the problem is solved… Still don’t know why it happened,