Ticket #2172 (closed defect: worksforme)
VM Hangs (high CPU) after performing huge I/O in the guest
|Reported by:||singh.gurjeet||Owned by:|
|Version:||VirtualBox 1.6.4||Keywords:||High CPU Vista Ubuntu Server|
Host: Windows Vista Business (with all the updates applied) Guest: Ubuntu Server 8.04, on 64MB RAM, Host networking over wireless, using DHCP. Running in Headless mode using VBoxHeadless.exe H/W: Lenovo Thinkpad R61i, with 2GB RAM, Intel Centrino Duo. S/W on Guest: .) Corrected Console framebuffer with 'vga=771' (or something similar) on the kernel line. .) Using apt-get, installed 'cvs make gcc libc-devel readline-dev flex bison'. .) Downloaded (using CVS), compiled (with no custom flags to ./configure), installed and running PostgreSQL DB version 8.3.3. .) Running 6 instances of a bash script that scrapes web and inserts data into Postgres database.
Initial diagnosis done using ProcessExplorer, some screenshots attached showing the call-stack of the thread consuming most of the CPU because it is performing so many Context-Switches (sometimes as high as 31600 per second)!
I performed a SELECT on a Postgres 8.3.3 database table that was about 50MB in size, and saw that the for about three minutes the VM performed huge I/O; 11-13 MB/s of read and 1-4 MB/s write. After this, the I/O storm stopped just as immediately as it started, but now the VM started consuming huge CPU!
The VM has been running for over half an hour now, consuming 100% of CPU on one of my 2 CPUs. I have paused and restarted the VM from GUI twice in the hopes of resetting some state and bringing the VM to normalcy, but to no avail!!!
I'll keep this VM running for next few hours or so, so that I can provide some useful info, if somebody asks.