Hi! Anthony Brock wrote:
> > I have 4 GB of physical RAM in the Ubuntu box + 3 GB swap. It is > > running a vanilla 2.6.17.8 kernel (no skas3 patches, because I haven't > > successfully managed to apply any sets of skas3 patches) > Here is an interesting problem. Each instance has 48M. You're launching 50 > instances. This means you're allocating up to 2.4 GB for instances. However, > you're also giving them 3 GB of swap. Do they need the swap? If not, get rid > of it (or at least lock your existing memory into ram). If you are using sparse file for swap files I don't think it will take more than tenth of that space. > > guest machines randomly crash. They aren't sending me anything via > > syslog (I've configured them to log to the host machine), and they don't > > appear to log anything to STDOUT. I can make machines crash with the > > message in the subject line, by simply working them too hard (e.g. log > > in, fire off a few dozen shells, add about 1000 users as fast as bash > > can go through a for loop). My students, however (up to 25 working > > simultaneously on UML guests), are making the machines crash by doing > > nothing more than adding two or three users manually, looking at man > > pages, and typing 'ls'. > > 50 machines doing ls (including swapping memory to and fro) could cause > enough IO cause significant pauses. However, I can't explain the crashes. > UML has been quite stable for me even under heavy load. I had a problem where umls could sometimes crash and I found out that my /dev/shm was too little. After I set it much bigger I haven't had any problems with stability. Regards, Jyrki Jaakkola ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ User-mode-linux-user mailing list User-mode-linux-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user
