Ok, sounds good .. could I also draw your attention to the "deploy" script,
which is the other
script I need to modify .. my version looks like this;
--
mkdir -p `dirname $domain`
cat > $domain
logger "DEPLOY :: /var/lib/one/remotes/hooks/vdc/deploy.py $domain"
/var/lib/one/remotes/hooks/vdc/deploy.py $domain
data=`virsh --connect $LIBVIRT_URI create $domain`
--
Deploy does three relatively critical things you may wish to consider;
a. adds the "sharable" flag to the libvirt config - without this libvirt won't
live migrate (on the latest versions of libvirt)
b. adds "error_policy=stop" to ensure the VM pauses in the case of an IO error,
which lets you fix the IO issue, then unpause it
c. adds "discard=unmap", which you need in order for KVM to support TRIM
requests properly
(we use TRIM to allow a VM to pass references to unused space to the back-end
storage so it can be released back to the OS)
If it's of any use, you're more than welcome to use my deploy.py script .. for
what it does it seems fairly concise .. :)
#!/usr/bin/python
import xml.etree.ElementTree as ET
from sys import argv
original = ET.parse(argv[1])
params = original.findall(".//disk")
for p in params:
if p.get('device') == 'disk': p.insert(0,ET.Element("shareable",{}))
params = original.findall(".//driver")
for p in params:
if p.get('type') == 'raw':
p.set("error_policy","stop")
p.set("discard","unmap")
original.write(argv[1])
Regards,
Gareth.
--
Gareth Bult
“The odds of hitting your target go up dramatically when you aim at it.”
See the status of my current project at http://vdc-store.com
----- Original Message -----
From: "Ruben S. Montero" <[email protected]>
To: "Gareth Bult" <[email protected]>
Cc: [email protected]
Sent: Monday, 13 January, 2014 3:41:50 PM
Subject: Re: [one-dev] Live migration / recovery
Totally agree, in fact we've seen this in the past.
This is fairly easy to add, one_vmm_exec.rb includes a pseudo-dsl to specify
the actions, each action includes a fail action. Looking at the code we have
also to roll-back the networking configuration on the target host.
Added a new issue for this. In the meantime we can just use the previous
workaround.
http://dev.opennebula.org/issues/2633
On Mon, Jan 13, 2014 at 2:59 PM, Gareth Bult < [email protected] > wrote:
Ok, this almost seems too easy ... :)
What I was trying to avoid was more tweaking of ON files when installing VDC.
The issue I see is that each time someone upgraded ON, they will potentially
have a chain of
small patches to apply ... if I supply a few small patches based on "if <vdc
installed> - do something extra"
would you include these in the stock scripts??
Gareth.
--
Gareth Bult
“The odds of hitting your target go up dramatically when you aim at it.”
See the status of my current project at http://vdc-store.com
From: "Ruben S. Montero" < [email protected] >
To: "Gareth Bult" < [email protected] >
Cc: [email protected]
Sent: Sunday, 12 January, 2014 10:36:30 PM
Subject: Re: [one-dev] Live migration / recovery
Hi Gareth
As the migrate script can be easily updated we do not provide any hook for
that. I'd go to kvm/migrate, and do a simple if [ $? ... after the virsh
command to kill the cache on the target host.
Cheers
Ruben
On Thu, Dec 19, 2013 at 12:54 PM, Gareth Bult < [email protected] > wrote:
<blockquote>
Hi,
I implemented live migration for the VDC driver a few weeks back and on the
whole it seems to work
quite well. The "premigrate" script creates a cache instance on the target
server and puts the source
cache into proxy mode, then the "postmigrate" script kills the original cache
instance.
Problem :: if the migration fails, I'm left with a running cache on both the
source and target servers, with
the source cache in proxy mode. I have a 1-line CLI command to revert the
issue, but I need to hook into
the system in order to call it.
How to do I do this, I guess effectively I need something like
"postmigrate_fail" .. ???
tia
Gareth.
--
Gareth Bult
“The odds of hitting your target go up dramatically when you aim at it.”
_______________________________________________
Dev mailing list
[email protected]
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--
--
Ruben S. Montero, PhD
Project co-Lead and Chief Architect
OpenNebula - Flexible Enterprise Cloud Made Simple
www.OpenNebula.org | [email protected] | @OpenNebula
</blockquote>
--
--
Ruben S. Montero, PhD
Project co-Lead and Chief Architect
OpenNebula - Flexible Enterprise Cloud Made Simple
www.OpenNebula.org | [email protected] | @OpenNebula
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