Re: Unable to start more than 14 domUs - libxl__xs_transaction_commit: could not commit xenstore transaction

[Jürgen Groß <jgross@xxxxxxxx>]

On 04.06.20 14:00, J. Roeleveld wrote:
> On Wednesday, June 3, 2020 3:26:19 PM CEST Jürgen Groß wrote:
> > On 03.06.20 15:01, J. Roeleveld wrote:
> > > On Wednesday, June 3, 2020 2:56:06 PM CEST Jürgen Groß wrote:
> > > > The default is 1000, you can set the value via the -E start parameter of
> > > > xenstored (e.g. "-E 5000" to set it to 5000), or if you are using
> > > > oxenstored by editing your /etc/xen/oxenstored.conf file (entry
> > > > "quota-maxentity").
> > > Has this default been changed/lowered?
> > > Or has there been an increase in amount of values in xenstore?
> > Depends. Which Xen version did you use before, and which Xenstore
> > variant (xenstored, oxenstored, or xenstore-stubdom) are you using?
> > Did you change anything in the driver domain?
> My previous version was 4.11.2.
> Using xenstored.
> No changes done to the driver domain.
> - Issue occured initially when driver domain was still on 4.11.2
> - Issue still occured when driver domain was upgraded to 4.12.2
>
> In my opinion, putting a quota on the xenstored database at 1000kb is far too
> low. I am not doing anything special and have had no issues running over 20
> VMs simultaneously in the past.
The quota is for number of Xenstore entries per domain.

> Suddenly encountering this is unexpected and, if sane defaults are used,
> unnecessary.
>
> Do you happen to know if this limit was changed between 4.11 and 4.12 or if
> the xenstored usage increased without realising?
The default limits didn't change.

I could imagine that the number of Xenstore entries per device did
change. I'm not aware of any other changes which could explain the
different behavior.

> I also can not find any list of "xenstored" commandline options to change
> these settings on the xen-website or anywhere else. What do I need to put into
> google to find this?
xenstored --help

will list all options.

I should note that I have raised this issue in the community and we'll
discuss how to address it (e.g. by adding per-domain Xenstore quota via
the domain config).


Juergen