[libvirt-users] /proc/meminfo

[Peter Steele]

On 03/25/2016 03:17 AM, mxs kolo wrote:
>>> I found a download for this version and tried it out but we ran into a
>>> different set of problems when running our software in containers under
>>> this environment.
> What kind problem ? Network ?
>
That's a good question and I don't have a good short answer. We have an 
automated installation framework that installs a minimal CentOS (around 
450 packages) on multiple servers that act as "hypervisors" and installs 
under that multiple containers (comprised of about 300 packages) that 
run our core software in a clustered configuration. Our software runs 
reasonably well under the set of CentOS 7.1 packages we've been using. 
In upgrading to CentOS 7.2, we're hitting a number of problems in our 
software, some of them network related, some of them appearing to be 
caused by the incorrect information in /proc/meminfo.

Upgrading libvirt to 1.3.2 caused even more issues. For some reason our 
C programs all hung on futex calls as they were opening their log files. 
We've seen a lot of weird stuff in trying to upgrade to 7.2 but this was 
a new one. I did not dig deep into the cause, mainly due to time.

The version of libvirt we're using under CentOS 7.1 is 1.2.16. This 
appears stable enough, although not without its own issues. One reason 
we were looking to upgrade to 7.2 was because of an problem with 
networking we hit in 7.1. Our cluster nodes use dual network ports for 
redundancy and performance. We typically use bond mode 6, at least back 
in the CentOS 6.5 era of our software. In moving to CentOS 7.1, we hit 
an issue with bond mode 6 where the arp tables were not getting 
populated on the servers. This caused containers hosted on one server 
not being able to communicate with containers hosted on another server. 
We had to switch to bond mode 1 to get around this issue.

We determined that this bond mode issue was resolved in 7.2 and that's 
why we wanted to upgrade. But with these other issues we've run into in 
7.2 we're pulling the plug and sticking with 7.1. When this release 
cycle is over, we'll revisit 7.2/7.3.