[Users] memory leak in 2.6.18 ovz kernels

[Cliff Wells]

Hi,

I've been running 2.6.18 releases on two servers and both of them have
suffered a slow but steady memory leak.  The first server is a dual
Athlon MP with 3GB of RAM, the second a quad Opteron 275 with 8GB of
RAM.  I first noticed the issue on the Opteron a few days ago when I
realized it was using 7.6GB of RAM and had started using swap (it's only
got about 2GB allocated to VE's).  Today the Athlon died after
exhausting memory.  Both had been up for around 70 days.

When investigating the situation on the Opteron, I stopped all the VE's
but no memory was reclaimed.  Nothing in "top" showed any significant
memory consumption.  I wasn't able to investigate on the Athlon system
as it was in an unusable state.

My immediate solution was to upgrade the Opteron system to 2.6.24 and
boot the Athlon system into a stock kernel (I'm not currently using
OpenVZ on it).

Anyway, my concern is that I've seen no mention of similar issues from
anyone else (and in fact, until the Athlon server failed today, I was
inclined to believe it was a configuration issue on the Opteron), so I
have a fear that if there is a leak, it might still exist in newer
kernels.

I'm going to babysit these machines to see if the problem reappears, but
has anyone else noticed similar patterns of memory consumption and is
there anything I can do to track this down?

Regards,
Cliff