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Hi, On Thu, 2003-04-17 at 23:19, Ram Pai wrote: > Hi, > > Will OGFS continue using its own internal cluster manager? or > will it use an external cluster manager? and if so which cluster > manager? > > For OGFS to work with EVMS properly, it is essential that > they orchestrate their interaction through the same cluster manager. > > This issue is core for integration of EVMS with OGFS. > > Any thoughts on this? I am not sure how evms does the recovery. Is it happen by running commands in the user space . With open ssi cluster things can work in the following way. -Remember now everything is going to be inside kernel- -AFAIK openssi as of now doesn't support split brain detection ( STONITH ) Once implemented i guess it will done at the Membership level so that any subsystem registered with membership will have a consistent view of the cluster - 1) evms if it keeps the cluster topology information as openDLM, will get the topology information from Cluster Membership Subsystem(CLMS) of openssi. This is true for opengfs also. CLMS subsystem make sure that both evms and opengfs get the same topology of the cluster.(One thing i found with openDLM was assuming max number of nodes in the cluster. This is wrong. Rather any subsystem should query the CLMS for finding out maximum number of node supported. ) 2) evms will register for cluster member ship events. This include node up and node down event. 3) opengfs will also register for cluster membership service but will depend on the Volume manager to finish its job first before starting of. This can be a part of generic framework where opengfs get layered on top of any Volume manager. It need to wait for Volume manager to finish it work. In the case of openssi there is a priority associated to each routine registered for cluster events and the routines are executed in order from higher priority(0) to lower priority. So evms can register for priority 0 and opengfs can register for priority 1. Now if you want to do some activity before joining the cluster and immediately after pre join and post join phase hooks are provided along with registering cluster membership services. For more information http://ci-linux.sourceforge.net/enhancing.shtml 4) If needed both evms and opengfs can use openDLM API's for locking. which again get the membership information from CLMS subsystem. I know openDLM have some scaling problems. Now as i see from the mailing list as of now opengfs depend on the locking module to take care of all cluster related events. I guess this may need to change in such a way that opengfs internally does File system related recovery taking proper locks and lock manager ( openDLM or any other lock manager) does the recovery action needed for locks. I am marking the mail to openssi mailing list, so that people over there can correct me if i am wrong. -aneesh ------------------------------------------------------- This sf.net email is sponsored by:ThinkGeek Welcome to geek heaven. http://thinkgeek.com/sf _______________________________________________ Opengfs-devel mailing list Opengfs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/opengfs-devel