I accidentally changed some configuration of a VM and it refused to start after reboot, I know I can simply revert what I changed to make it works again so to avoid recovery process, and I found this great article which described exactly what I want. I’m going to repeat the steps here as I also need to write steps to unmount. Note that you need to have kpartx installed. Continue reading »
Finally I decide to turn on console on all my VMs so that I don’t have to rely on VNC for remote access whenever network is having problem – I’m trying to join corp network now and there are lots of network glitches during last week and I believe there will still be some in the coming week.
Actually it’s not that complicated, on CentOS (5 or 6) machines, add following line to /etc/inittab (do a dmesg | grep tty to make sure it is ttyS0 for you, but I believe they are all the same for kvm based VMs): Continue reading »
There was not much progress with performance test as mentioned here.
I first did test with LDAP vs. memcached, then found there was not much difference between those two, which is suspicious, so I started running test to compare pure database and memcached solution, which ideally should show lot of difference, but I failed.
I still haven’t figured out what was the real cause, it seems VM is not that good to do this kind of test – thinking of limited resource (CPU, mem, network, disk, etc), all VMs will compete each other. Again, this is my guess and I will try to see what would be the best solution to get performance done in VM environment.
Even if I failed, it shows that VM will not be good for performance testing, nice try ๐ .