On 2014-06-15 19:48, Edwin Marqe wrote:
Thanks Bjoern. Does your last point mean that after the client reconnects it would recover the last known state it had on the failed server, meaning i.e. the same windows opened, same desktop configuration etc? In this case, would that mean that there's also a 'home' sincronization between the failover group servers?
Agreeing with Bjoern, I want to address the last sentence: do you mean a home directory here, and their synchronization among Sun Ray servers? With any sufficiently large installation (and having several terminal servers alone qualifies for that, IMHO) you should really look towards a centralized networking infrastructure, which includes home directories residing on an NFS server and user accounts (especially non-kiosk ones) defined in the LDAP catalogs (Sun DSEE, Oracle DSEE, ForgeRock OpenDJ, maybe even OpenLDAP or MS Active Directory with Unix extensions). For more resilience, you might replicate the LDAP catalogs, maybe keeping a copy on each server and preferring it to the other copies (search order, which can be defined in LDAP client profiles stored in the catalog, and you assign each server to its own profile). While it is discouraged by documentation, there are tricks to allow a server hosting the LDAP service to be its own client. As one of the attributes in LDAP accounts you can specify the home directories (though it is usually /home/username for all) and also you can define automounter maps for autofs (so that if you have several NFS servers hosting different sets of users - these relations can be defined here). For failover of the homedir storage you use any number of solutions, but should really prefer those based on OpenZFS with illumos or BSD kernels (commercial or free, though the reliable/HA ones tend to be more expensive in gear and paying a price to one of the many developer companies for software license and support is reasonable to keep the setup running). In particular, for NFS and ZFS you should look towards systems with dedicated ZIL (write-logging) devices preferably with DDR RAM for active storage rather than SSDs or HDDs, since all NFS write I/O is synchronous by design and lags greatly on ordinary HDDs (must be really committed to storage before ACKing, and servers that don't do this and seem fast - they lie and are an accident waiting to happen in an emergency poweroff, kernel crash, etc. which would not let them flush the caches for the delayed writes). HTH, Jim Klimov _______________________________________________ SunRay-Users mailing list [email protected] http://www.filibeto.org/mailman/listinfo/sunray-users
