Reply to Valeriy below and to Marc further below...
On 12/03/2014 02:39 AM, Valeriy Ponomaryov wrote:
According to (2) - yes, analog of Cinder's "manage/unmanage" is not
implemented in Manila yet.
Manage/unmanage is a feature I'm very interested in seeing in Manila. I
suspect it will be harder to get right in Manila than it was for Cinder,
however, and more importantly, getting it right will depend a lot on the
work that's going on right now to support pools and driver modes. For
Manila core it won't actually be that much work but for individual
drivers, implementing manage/unmanage can be a huge amount of work, so
we should try to define the semantics of manage/unmanage at the project
level to strike a good balance between usefulness to administrators and
making it practical to implement.
On Wed, Dec 3, 2014 at 9:03 AM, Marc Koderer <[email protected]
<mailto:[email protected]>> wrote:
Hi Valeriy,
thanks for feedback. My answers see below.
Am 02.12.2014 um 16:44 schrieb Valeriy Ponomaryov
<[email protected] <mailto:[email protected]>>:
> Hello Marc,
>
> Here, I tried to cover mentioned use cases with "implemented or
not" notes:
>
> 1) Implemented, but details of implementation are different for
different share drivers.
> 2) Not clear for me. If you mean possibility to mount one share
to any amount of VMs, then yes.
That means you have an existing shared volume in your storage
system and import
it to manila (like cinder manage). I guess this is not implemented
yet.
> 3) Nova is used only in one case - Generic Driver that uses
Cinder volumes. So, it can be said, that Manila interface does
allow to use "flat" network and a share driver just should have
implementation for it. I will assume you mean usage of generic
driver and possibility to mount shares to different machines
except Nova VMs. - In that case network architecture should allow
to make connection in general. If it is allowed, then should not
be any problems with mount to any machine. Just access-allow
operations should be performed.
This point was actually a copy from the wiki [1]. I just removed
the Bare-metal point
since for me it doesn’t matter whether the infrastructure service
is a Bare-metal machine or not.
> 4) Access can be shared, but it is not as flexible as could be
wanted. Owner of a share can grant access to all, and if there is
network connectivity between user and share host, then user will
be able to mount having provided access.
Also a copy from the wiki.
> 5) Manila can not remove some "mount" of some share, it can
remove access for possibility to mount in general. So, looks like
not implemented.
> 6) Implemented.
> 7) Not implemented yet.
> 8) No "cloning", but we have snapshot-approach as for volumes in
cinder.
Regards
Marc
>
> Regards,
> Valeriy Ponomaryov
> Mirantis
>
> On Tue, Dec 2, 2014 at 4:22 PM, Marc Koderer <[email protected]
<mailto:[email protected]>> wrote:
> Hello Manila Team,
>
> We identified use cases for Manila during an internal workshop
> with our operators. I would like to share them with you and
> update the wiki [1] since it seems to be outdated.
>
> Before that I would like to gather feedback and you might help me
> with identifying things that aren’t implemented yet.
>
> Our list:
>
> 1.) Create a share and use it in a tenant
> Initial creation of a shared storage volume and assign it
to several VM’s
This is the basic use case for Manila and I hope it's obvious that this
works.
> 2.) Assign an preexisting share to a VM with Manila
> Import an existing Share with data and it to several VM’s
in case of
> migrating an existing production - services to Openstack.
Covered above.
> 3.) External consumption of a share
> Accommodate and provide mechanisms for last-mile
consumption of shares by
> consumers of the service that aren't mediated by Nova.
Depending on how you look at this, it either already works or it's out
of scope for Manila. Now that we're looking at mount automation we may
be more involved in this area, but nothing about Manila prevents the use
of shares by something other than nova.
> 4.) Cross Tenant sharing
> Coordinate shares across tenants
As above, this is considered out of scope, but we believe it's easy to
make this work with no changes to Manila.
> 5.) Detach a share and don’t destroy data (deactivate)
> Share is flagged as inactive and data are not destroyed for
later
> usage or in case of legal requirements.
Can't this be achieved by simply removing all access? By default, the
shares manila creates are not accessible to anyone. Access must be
granted explicitly.
> 6.) Unassign and delete data of a share
> Destroy entire share with all data and free space for
further usage.
This is another core feature that already works.
> 7.) Resize Share
> Resize existing and assigned share on the fly.
Similar to manage/unmanage, this is very easily to conceptually
understand, but not always easy to implement, due to the vagaries of
real storage systems. There are some storage systems that can easily do
this (such as NetApp) but others would find it quite challenging.
Interestingly, for those that have difficulty resizing shares, resizing
larger is often easier than resizing smaller. Cinder has made the design
choice to support expanding volumes but NOT to support shrinking
volumes. This is an area where we should consider making the resize
feature optional, or at least making the shrinking optional if we decide
to support expanding across the board.
> 8.) Copy existing share
> Copy existing share between different storage technologies
Is this an analog for the cinder migrate feature? Hopefully it's obvious
that anyone can copy a share to another share with the "cp -ar" command
from a host that's connected to both shares. For copying across
technologies, I suspect you can't do much better than this. For copying
within the same family of backends, we already have snapshot and
create-share-from-snapshot, and we could add optimized migration paths
if we did implement a manila-managed migration feature.
> Regards
> Marc
> Deutsche Telekom
>
> [1]: https://wiki.openstack.org/wiki/Manila/usecases
>
>
>
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>
> --
> Kind Regards
> Valeriy Ponomaryov
> www.mirantis.com <http://www.mirantis.com>
> [email protected] <mailto:[email protected]>
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Kind Regards
Valeriy Ponomaryov
www.mirantis.com <http://www.mirantis.com>
[email protected] <mailto:[email protected]>
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