0( GIC E Global VM migration is also available by sharing "storage space" by VM host machines. Real time availability makes it possible. Actual data copy follows. (VM operator need virtually common Ethernet segment and fat pipe for memory copy) TOYAMA site OSAKA site TOKYO site before Migration Copy to DR-sites Copy to DR-sites live migration of VM between distributed areas real time and active-active features seem to be just a simple "shared storage". Live migration is also possible between DR sites (it requires common subnet and fat pipe for memory copy, of course) after Migration Copy to DR-sites
E . C Front-end servers aggregate client requests (READ / WRITE) so that, lots of back-end servers can handle user data in parallel & distributed manner. Both of performance & storage space are scalable, depends on # of servers. front-end (access server) Access Gateway (via NFS, CIFS or similar) clients back-end (core server) WRITE req. write blocks read blocks READ req. scalable performance & scalable storage size by parallel & distributing processing technology
AI E GC 1. assign a new unique ID for any updated block (to ensure consistency). 2. make replication in local site (for quick ACK) and update meta data. 3. make replication in global distributed environment (for actual data copies). back-end (multi-sites) a file, consisted from many blocks multiplicity in multi-location, makes each user data, redundant in local, at first, 3 distributed copies, at last. (2) create 2 copies in local for each user data, write META data, ant returns ACK (1) (1') (3-a) (3-a) (3-a) make a copy in different location right after ACK. (3-b) remove one of 2 local blocks, in a future. (3-b) (1) assign a new unique ID for any updated block, so that, ID ensures the consistency Most important ! the key for "distributed replication"
and evaluating the storage along with various applications. The main advantage of our storage is its very fast random I/O performance, even though it provides a POSIX compatible file system interface on the top of distributed cluster storage.