Hi. > I will try. Shared block storage is a block device like /dev/sda > accessible on more than one server at once. This may be a plain hard-disk > or a hardware RAID. Coordination among the servers is handled on the file > system level above that - for example by OCFS or GFS. Using a normal file > system like Ext3 is not possible for read/write operations to the same > shared block storage since the servers would get very confused. > Thanks for the info. > As far as I know; Lustre in itself do not handle redundancy or fault > tolerance. In order to get redundancy for Lustre (unlike GlusterFS or > Ceph) that must be handled by some kind of shared storage. And Lustre > needs the data to be stored on a block device. > > Using shared block storage to keep the data on (usually a hardware RAID on > a SAN) makes it to move the service from one physical server to another. > > Example: normally one server is taking care of service A and another > server is taking care of service B. The first server is also passively > taking care of service B and the other server passively taking care of > service A. When the first server goes down the other server is taking over > service A, which means both A and B are located on the same server. > So basically the data stored on 2 nodes, but their coordination requires a shared block device? Because they do seem to speak about specific storage nodes - but I might not understand this correctly. Regards. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://zresearch.com/pipermail/gluster-users/attachments/20090120/a5e5ba32/attachment.htm
