FC11 - KVM based VM become halt after heavy rsync

[Tony Nelson]

On 09-08-31 15:40:08, Linux student wrote:
> Mohammad Mateen Aslam on 2009-08-28 19:14 PM +0500, wrote :
> > Hi guys
> >
> > I have am using FC11 64bit on Host and same OS on KVM based guest
> > machine. I am using TAP based routing network inside host. I am 
> > using virtio network driver for my guest machine
> >
> > When i transfer huge data via rsync from another live host my guest
> > machine got halt with following errors in log. I need to restart
> > network service to make guest VM back. 
> >
> > With 512M RAM for guest VM, it got halt for 5G data transffer via
> > rsync With 1G RAM  for guest VM, it got halt if  i try to shift 15G 
> > data transffer via rsync
> >
> > Aug 28 12:43:08 phili-p kernel: swapper: page allocation failure.
> > order:0, mode:0x20
 ...

> > Note: i want to use my VM for heavy rsync backups. Experts are 
> > request to have some solution for the problem
 ...
> Any one facing same problem?..

No, but I do use rsync.  It appears that the VM is running out of 
memory.  You don't give your rsync command, but I suspect that you are 
using an option that requires extra memory, such as "-H" (preserve hard 
links), or possibly not using "-r" (recursive) for the new incremental 
scan that doesn't need to load all the directory info into memory.

Rsync can use a lot of memory if some file being tranfered is huge.  It 
will use less memory for the same amount of data in smaller files.

You don't say quite what you're doing, but if you are just copying the 
data (that is, there isn't a destination that is nearly the same), you 
might not need to use rsync at all, but some other file copy utility 
instead, such as scp (slow but secure and reliable).  Umm, when I want 
to copy a few GiB from a VM to the host, I now shut down the VM and 
mount its root locally, and do a normal copy.

-- 
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