Tying this with your other thread, if you always take a lock before
mapping an image, you could just list the lockers.  Unlike a watch,
a lock will never disappear behind your back ;)

Thanks,

                Ilya

On Thu, Apr 9, 2020 at 9:24 PM Void Star Nill <[email protected]> wrote:
>
> Thanks Ilya. Is there a more deterministic way to know where the volumes are 
> mapped to?
>
> Thanks,
> Shridhar
>
>
> On Wed, 8 Apr 2020 at 03:06, Ilya Dryomov <[email protected]> wrote:
>>
>> A note of caution, though.  "rbd status" just lists watches on the
>> image header object and a watch is not a reliable indicator of whether
>> the image is mapped somewhere or not.
>>
>> It is true that all read-write mappings establish a watch, but it can
>> come and go due to network partitions, OSD crashes or general cluster
>> issues.  When the client notices that it lost a watch, it attempts to
>> reestablish it, but this doesn't happen immediately.
>>
>> Thanks,
>>
>>                 Ilya
>>
>> On Tue, Apr 7, 2020 at 8:12 PM Void Star Nill <[email protected]> 
>> wrote:
>> >
>> > Thanks Jack. Exactly what I needed.
>> >
>> > Appreciate quick response.
>> >
>> > Regards,
>> > Shridhar
>> >
>> >
>> > On Tue, 7 Apr 2020 at 10:00, Jack <[email protected]> wrote:
>> >
>> > > Hi,
>> > >
>> > > Checkout rbd status <image>
>> > > For instance:
>> > > root@ceph5-1:~# rbd status vm-903-disk-1
>> > > Watchers:
>> > >         watcher=10.5.0.39:0/866486904 client.522682726
>> > > cookie=140177351959424
>> > >
>> > > This is the list of clients for that image
>> > > All mapping hosts are in it
>> > >
>> > >
>> > > On 4/7/20 6:46 PM, Void Star Nill wrote:
>> > > > Hello,
>> > > >
>> > > > Is there a way to find out all the clients where the volumes are mapped
>> > > > from a central point?
>> > > >
>> > > > We have a large fleet of machines that use ceph rbd volumes. For some
>> > > > maintenance purposes, we need to find out if a volume is mapped 
>> > > > anywhere
>> > > > before acting on it. Right now we go and query each client machines 
>> > > > with
>> > > > `rbd showmapped` commands. Is there a variant of this CLI that lists 
>> > > > all
>> > > > mappings on a single node (ceph mon for instance)?
>> > > >
>> > > > Thanks,
>> > > > Shridhar
>> > > > _______________________________________________
>> > > > ceph-users mailing list -- [email protected]
>> > > > To unsubscribe send an email to [email protected]
>> > > >
>> > > _______________________________________________
>> > > ceph-users mailing list -- [email protected]
>> > > To unsubscribe send an email to [email protected]
>> > >
>> > _______________________________________________
>> > ceph-users mailing list -- [email protected]
>> > To unsubscribe send an email to [email protected]
_______________________________________________
ceph-users mailing list -- [email protected]
To unsubscribe send an email to [email protected]

Reply via email to