I have two physical machine, each of them have running a kvm vm for testing. the vm is running windows 2008 R2.
one vm took about 25 min to do image backup (27GB), which I think it is fine.
but the other vm took 180 min to do backup (40GB), which I think it is too slow.
the two physical machine are the same. there is one running process in the slow vm, which take about 20% cpu time, I don’t know if it is the reason why urbackup client keep idle? do urbackup client will only try to work when there is no other process running?
how can I make urbackup work harder so the backup time can be finished sooner?
PS: after finish full backup, I tried to do incremental image backup at the slow machine. and after 3 hours it only backup 10%. I really need to make it work harder. the system is not idle but the loading is light.
any suggestion about how to tune the client? I try to install 3 kvm vm at 3 physical machines. if the vm is totally idle, then full image backup and incremental image backup took about the same time (15 min to backup 25GB). but when the vm is under light loading,
full image backup maybe normal (15 min) or long (3 hours), and incremental image backup took even longer (at least 3 hours to finish).
thanks a lot for help!! I haven’t done all the testing. since the testing spent time, I think I should report what I have do till now.
I had played with ProcessHacker these days. at first I just changed the cpu priority and io priority of “UrBackupClientBackend.exe”. but it is useless. then your post told me I should click the process and go to “thread” submenu to change the priority. I saw two threads with “-4” priority, so I changed them but still useless. and then I notice when I start backup, there will be a new thread with “idle” and “very low” priority, I change the thread with “time critical” and “very high”. and this time I finally saw some approvement, the full image backup now use 35 min to finish.(need 3 hours before). and the incremental image backup is faster. it is still running now, maybe need 3 hours to complete (maybe need 30 hours to finish before, I never let it finish).
but the whole speed is still not very usable. I have three windows 2008 R2 vm and the speed meter is:
a new idle vm, with 1 vcpu and 2g vram, about 1X gb disk usage at 40GB virtual disk => full image backup 17 min, incremental image backup 16 min. without any process priority tuning.
vm running IIS webserver. with 4 vcpu and 8G vram, about 20gb disk usage at 40GB virtual disk => full image backup 16 min, incremental image backup 100 min. without any process priority tuning.
vm running sql server. with 4 vcpu and 16G vram. about 30gb disk usage at 60GB virtual disk => full image backup 3 hours, incremental image backup maybe 30 hours. with process tuning now full image backup took 35 min, incremental image backup maybe 3 hours.
the above data brings me several questions:
why incremental image backup is slow when system has loading.
I look at the process behavior when backup. the idle vm can keep reading disk at a constant speed. but the loading vm will burst the disk read, and idle for several seconds, then read again. if the I change the process priority, it will keep reading for longer period, and idle for shorter period, so overall it will become faster. if it can sustain the reading speed without idle, I think the problem will be solved.
there will be new thread when start backuping. so it is very hard to tune. will it be possible to have options for priority in future versions.
I need to backup the server at night. and I hope it can be done as soon as possible…thanks again for your help!!
Your investigation also probably helped me to understand the cause of the bursty/unperformant behaviour. It’s the intermingling of the device access and CPU intensive work, while the device access is unbuffered. Will try to think of a solution to that, but it will be a bit of work.