Open Stack

Hi,

Let me comment inline.


On Mon, Dec 28, 2015 at 7:06 PM, Andrew Woodward <xarses at gmail.com> wrote:

> In order to ensure that LVM can be configured as desired, its necessary to
> purge them and then reboot the node, otherwise the partitioning commands
> will most likely fail on the next attempt as they will be initialized
> before we can start partitioning the node. Hence, when a node is removed
> from the environment, it is supposed to have this data destroyed. Since
> it's a running system, the most effective way was to blast the first 1Mb of
> each partition. (with out many more reboots)
>
> As to the fallback to SSH, there are two times we use this process, with
> the node reboot (after cobbler/IBP finishes), and with the wipe as we are
> discussing here. These are for the odd occurrences of the nodes failing to
> restart after the MCO command. I don't think anyone has had much success
> trying to figure out why this occurs, but I've seen nodes get stuck in
> provisioning and remove in multiple environments using 6.1 where they
> managed to break the SSH Fallback. It would occur around 1/20 nodes
> seemingly randomly. So with the SSH fallback I nearly never see the failure
> in node reboot.
>

If we talk about 6.1-7.0 release there shouldn't be any problems with mco
reboot. SSH fallback must be deprecated at all.


>
>

>

>

> On Thu, Dec 24, 2015 at 6:28 AM Alex Schultz <aschultz at mirantis.com>
> wrote:
>
>> On Thu, Dec 24, 2015 at 1:29 AM, Artur Svechnikov
>> <asvechnikov at mirantis.com> wrote:
>> > Hi,
>> > We have faced the issue that nodes' disks are wiped after stop
>> deployment.
>> > It occurs due to the logic of nodes removing (this is old logic and
>> it's not
>> > actual already as I understand). This logic contains step which calls
>> > erase_node[0], also there is another method with wipe of disks [1].
>> AFAIK it
>> > was needed for smooth cobbler provision and ensure that nodes will not
>> be
>> > booted from disk when it shouldn't. Instead of cobbler we use IBP from
>> > fuel-agent where current partition table is wiped before provision
>> stage.
>> > And use disks wiping for insurance that nodes will not booted from disk
>> > doesn't seem good solution. I want to propose not to wipe disks and
>> simply
>> > unset bootable flag from node disks.
>>
>
Disks must be wiped as boot flag doesn't guarantee anything. If bootlag is
not set, BIOS will ignore ignore the device in boot-order. More over, 2
partitions may have bootflag or operator may set to skip boot-order in BIOS.

>
>> > Please share your thoughts. Perhaps some other components use the fact
>> that
>> > disks are wiped after node removing or stop deployment. If it's so, then
>> > please tell about it.
>> >
>> > [0]
>> >
>> https://github.com/openstack/fuel-astute/blob/master/lib/astute/nodes_remover.rb#L132-L137
>> > [1]
>> >
>> https://github.com/openstack/fuel-astute/blob/master/lib/astute/ssh_actions/ssh_erase_nodes.rb
>> >
>>
>> I thought the erase_node[0] mcollective action was the process that
>> cleared a node's disks after their removal from an environment. When
>> do we use the ssh_erase_nodes?  Is it a fall back mechanism if the
>> mcollective fails?  My understanding on the history is based around
>> needing to have the partitions and data wiped so that the LVM groups
>> and other partition information does not interfere with the
>> installation process the next time the node is provisioned.  That
>> might have been a side effect of cobbler and we should test if it's
>> still an issue for IBP.
>>
>
Since we do not use classical provision anymore, we have mco connection all
the time. During IBP we have it as part of bootstrap, after reboot, mco is
still present so all actions should be done via mco.


>
>>
>> Thanks,
>> -Alex
>>
>> [0]
>> https://github.com/openstack/fuel-astute/blob/master/mcagents/erase_node.rb
>>
>> > Best regards,
>> > Svechnikov Artur
>> >
>> >
>> __________________________________________________________________________
>> > OpenStack Development Mailing List (not for usage questions)
>> > Unsubscribe:
>> OpenStack-dev-request at lists.openstack.org?subject:unsubscribe
>> > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
>> >
>>
>> __________________________________________________________________________
>> OpenStack Development Mailing List (not for usage questions)
>> Unsubscribe:
>> OpenStack-dev-request at lists.openstack.org?subject:unsubscribe
>> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
>>
> --
>
> --
>
> Andrew Woodward
>
> Mirantis
>
> Fuel Community Ambassador
>
> Ceph Community
>
> __________________________________________________________________________
> OpenStack Development Mailing List (not for usage questions)
> Unsubscribe: OpenStack-dev-request at lists.openstack.org?subject:unsubscribe
> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstack.org/pipermail/openstack-dev/attachments/20151229/48975109/attachment.html>