Is it just me, or does HPC clustering and virtualization fall on opposite ends of the spectrum?
With virtualization, you are pooling many virtual OS/server instances on high availablility hardware, sharing memory and cpu as demanded, oversubscribing. What would be idle time on one server, is utilized by another loaded server. With HPC clustering, you are running many physical OS/server instances that usually do not need to be highly available, but instead need to have direct access and total utilization of memory, cpu and storage. If queuing is done well, all servers are maxed out for performance under load. With xen/vmware/amazon clusters, it seems that you would be adding the complexity and cost of a virtualization infrastructure, with few of the benefits that virtualization is targeted to solve. Cheers. On 01/26/2010 10:24 AM, Hearns, John wrote: > for starters to save on resourses why not cut out the gui and go commandline > to free up some more of the shared resources, and 2ndly wouldnt offloading > data storage to a san or nfs storage server mitigate the disk I/O issues? > > i honestly dont know much about xen as i just got my hands dirty with it. > wouldnt it be better then using software virtualization since xen takes > advantage of the hardware virtualization that most modern processors come > with? > > > Jonathan, in a private reply I've already said that you should not be put > off from having bright ideas! > > In no way wishing to rain on your parade - and indeed wishing you to > experiment and keep asking questions, > which you are very welcome to do, this has been thought of. > > Cluster nodes are commonly run without and GUI - commandline only, as you say. > The debate comes around on this list every so often about running diskless! > The answer is yes, you can run diskless compute > nodes, and I do. You boot them over the network, and have an NFS-root > filesystem. > On many clusters the application software is NFS mounted also. > > Your point about a SAN is very relevant - I would say that direct, physical > fibrechannel SAN connections in a cluster are > not common - simply due to the expense of installing the cards and a separate > infrastructure. However, iSCSI is used and > Infiniband is common in clusters. > > > Apologies - I really don't want to come across as knowing better than you > (which I don't). If we don't have people asking 2what if" and "hey - here's a > good idea" then you won't make anything new. > > > > The contents of this email are confidential and for the exclusive use of the > intended recipient. If you receive this email in error you should not copy > it, retransmit it, use it or disclose its contents but should return it to > the sender immediately and delete your copy. > > > _______________________________________________ > Beowulf mailing list, [email protected] sponsored by Penguin Computing > To change your subscription (digest mode or unsubscribe) visit > http://www.beowulf.org/mailman/listinfo/beowulf > _______________________________________________ Beowulf mailing list, [email protected] sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
