[CentOS-virt] /var/lib/xenstored & Xen4CentOS

Thu Jun 4 10:57:10 UTC 2015
George Dunlap <dunlapg at umich.edu>

On Thu, Jun 4, 2015 at 6:03 AM, Sarah Newman <srn at prgmr.com> wrote:
> By default, /var/lib/xenstored is mounted tmpfs in centos 5 but this doesn't appear to be true for Xen4CentOS. This can cause performance issues as
> mentioned in https://bugzilla.redhat.com/show_bug.cgi?id=446089
> I'm not sure if this should be part of xencommons, but if not, adding a tmpfs mount should probably be documented on the quick start wiki page.


Thanks for looking into this.

Adding a tmpfs mount to xencommons, if using the C xenstored, might be
a good idea -- I'll float that with upstream and see what they say.

As an alternate, can you try using the ocaml-based oxenstored (which
doesn't use the filesystem as its atomicity mechanism)?

To use oxenstored:
* Install the xen-ocaml package
* Reboot dom0
* Verify that oxenstored is running:
# ps ax | grep xenstore
  654 ?        S      0:00 /usr/sbin/oxenstored --pid-file

(On my to-do list is to get oxenstored into the core xen-runtime
package, which would also resolve this situation, I believe.)