El lun, 08-06-2009 a las 16:58 +0200, Rafael Micó Miranda escribió: > Hi, > > I have developed a couple of resources for Linux-Cluster (CMAN > +rgmanager) which try to fix some needs I see in Linux-Cluster when > compared with other cluster solution (concretely, Linux-HA a.k.a. > Heartbeat). I am a Linux-HA user and I think this two functionalities > could be useful in Linux-Cluster. > > I would like to give them (both resources) to the community to make them > be into the project, and maybe after testing/quality testing or so be > included into the RedHat Enterprise Linux packages of Linux-Cluster, so > RedHat will give support for them and include them into the > system-config-cluster tool to have a GUI that can configure this > resources and handle their information. > > I'll give you some details of both resources: > > 1.- ping-group: tries to bring to Linux-Cluster the Ping Group > functionality of Linux-HA. > > For those who don't know Ping Group, the idea is the following: its a > NODE functionality (not a service or a resource) that checks IP > communications with a list of given client nodes. When failed, Ping > Group will move all services running in the affected node to other nodes > that have proved that keep their communications right, so the service is > provided to the clients even if there is a network problem that affects > only a node of your cluster but the cluster itself wont realize about > it. > > I have developed ping-group as a resource to be used into a service of > your cluster, so in the resource arguments you can specify a list of > clients that service should take note on. There is one thing that could > be improved: ping-group will mark the service as failed even if the > other nodes of the cluster would fail too due to lack of communications > with the clients (for example, all clients are powered off). In this > situation the service will go on migrating from one node to another > according to your service failover policy and finally the service will > be stopped. Maybe some ideas could be useful to improve this behaviour. > > > 2.- lvm-cluster: tries to bring to Linux-Cluster an exclusive shared > storage option, using features of LVM2. I got accustomed to this kind of > volumes when working with Linux-Ha + EVMS solution (using Cluster > Segment Manager plug-in). > > When defining a new LVM2 volume four your cluster, you can set it as > cluster-disabled (the volume will behave as a local volume even if it is > on shared storage) or as cluster-enabled (the LVM volume can be > activated on many different cluster nodes at the same time). > > Of course, if the filesystem placed into the LVM volume is not a > clustered filesystem (GFS2) a cluster-enabled volume allows a bad > administrator mount a no-clustered filesystem (EXT3) in more than one > node of the cluster which may produce filesystem corruption. This is > because the LVM "open flag" of the filesystem is not propagated through > all the members of the cluster, so there is no knowledge of the state of > the filesystem and this situations can happen. > > This can be fixed with some of the options of LVM, specifically the > "enable exclusively flag". This flag, when used over a cluster-enabled > volume, will allow the VolumeGroup to be imported by all the nodes of > the cluster but the LogicalVolumes into the VolumeGroup can only be > activated by a single node. So, only one node of your cluster will have > the LogicalVolume device (for example /dev/VolGrp01/LogVol01) and the > problem explained above cannot happen. This is not about propagating the > "open flag" through the nodes, this is about making the LogicalVolume be > in only one node. > > I have developed lvm-cluster as a resource to be used into a service of > your cluster. In the arguments you an specify the name of the > VolumeGroup and the LogicalVolume to handle. > > > > So, I would like to receive the instructions to submit this two > resources to the project to improve them, test them and find any bugs > that could still be in the code. I have made some testing but of course > they need much more to allow them be put into the main project. > > Sincerely yours,
I received not even a simple reply, no one will help me? Thanks in advance, -- Rafael Micó Miranda
