Re: how to protect rbd from multiple simultaneous mapping

2013-01-25 Thread Andrey Korolyov
On Fri, Jan 25, 2013 at 7:51 PM, Sage Weil wrote: > On Fri, 25 Jan 2013, Andrey Korolyov wrote: >> On Fri, Jan 25, 2013 at 4:52 PM, Ugis wrote: >> > I mean if you map rbd and do not use "rbd lock.." command. Can you >> > tell which client has mapped certain rbd anyway? > > Not yet. We need to ad

Re: how to protect rbd from multiple simultaneous mapping

2013-01-25 Thread Sage Weil
On Fri, 25 Jan 2013, Andrey Korolyov wrote: > On Fri, Jan 25, 2013 at 4:52 PM, Ugis wrote: > > I mean if you map rbd and do not use "rbd lock.." command. Can you > > tell which client has mapped certain rbd anyway? Not yet. We need to add the ability to list watchers in librados, which will the

Re: how to protect rbd from multiple simultaneous mapping

2013-01-25 Thread Andrey Korolyov
On Fri, Jan 25, 2013 at 4:52 PM, Ugis wrote: > I mean if you map rbd and do not use "rbd lock.." command. Can you > tell which client has mapped certain rbd anyway? > > Ugis Assume you has an undistinguishable L3 segment, NAT for example, and accessing cluster over it - there is no possibility fo

Re: how to protect rbd from multiple simultaneous mapping

2013-01-25 Thread Wido den Hollander
On 01/25/2013 11:47 AM, Ugis wrote: This could work, thanks! P.S. Is there a way to tell which client has mapped certain rbd if no "rbd lock" is used? What you could do is this: $ rbd lock add myimage `hostname` That way you know which client locked the image. Wido It would be useful to s

Re: how to protect rbd from multiple simultaneous mapping

2013-01-24 Thread Sage Weil
On Thu, 24 Jan 2013, Mandell Degerness wrote: > The advisory locks are nice, but it would be really nice to have the > fencing. If a node is temporarily off the network and a heartbeat > monitor attempts to bring up a service on a different node, there is > no way to ensure that the first node wil

Re: how to protect rbd from multiple simultaneous mapping

2013-01-24 Thread Mandell Degerness
The advisory locks are nice, but it would be really nice to have the fencing. If a node is temporarily off the network and a heartbeat monitor attempts to bring up a service on a different node, there is no way to ensure that the first node will not write data to the rbd after the rbd is mounted o

Re: how to protect rbd from multiple simultaneous mapping

2013-01-24 Thread Josh Durgin
On 01/24/2013 05:30 AM, Ugis wrote: Hi, I have rbd which contains non-cluster filesystem. If this rbd is mapped+mounted on one host, it should not be mapped+mounted on the other simultaneously. How to protect such rbd from being mapped on the other host? At ceph level the only option is to use