Virtualization (or: it's about time)

Virtualization is everywhere these days (duh.) Because of increase in hardware performance, security requirements and the need to run several OS on one system, virtualization is now mainstream enough to be offered on desktop operating systems for the masses to use (Linux, OSX, Windows.) It is so far a x86 game only, although hypervisors for other architectures (like XScale) are in the work.

Hardware vendors are adding a lower level of instructions to help writing hypervisors that will control the VM supporting operating systems running at their current priviledge level. This pushes the security one level down while offering the devastating ability to compromise the software that manages the execution of all operating systems on the platform. This thread could be circumvented by the use of the TPM/PKI to ensure that the hypervisor isn't being tempered with (take a look at this diagram)

Some articles I should have read a long time ago.

There's certainly hope that hardware will address some of the existing performance degradations brought by virtualization. Some applications that could greatly benefit from virtualization can't suffer the I/O performance degradation that existing virtualization technology fails to entirely alleviate.

iSCSI, FCIP and iFCP.

The Fibre Channel protocol is a gigabit networking technology specifically developed for interconnecting servers and storage devices. Fibre Channel is based on the SCSI protocol.

iSCSI, FCIP and iFCP are storage protocols designed to use existing IP technologies, features and infrastructure:

• iSCSI encapsulate SCSI commands into TCP/IP traffic.
  
• FCIP encapsulate FC for transport over TCP/IP sockets. It's a tunneling protocol and it extends the FC fabric. FC services are kept intact. It relies on gateway to perform the encapsulation.
  
• iFCP replace lower-layer Fibre Channel transport with TCP/IP. FC transport services are being mapped to TCP/IP. This operation is realized by iFCP gateways. Once on IP, TCP/IP routing and switching can be used
  

I need to read two white papers to clarify a couple of things: one on iFCP and one on FCIP.

Quick read on CIFS

CIFS Common Internet File System:

• CIFS is M$ way of doing network file sharing
• Allows for sharing of file, directories, printers, etc...
• There are protocols for service announcement, naming, authentication, and authorization
• The file sharing protocol is Server Message Block (SMB.) originally developped to run over NetBIOS (now available over TCP/IP -- NBT)
• NBT: three services must be implemented:
  
  
  
  1. Name service (NetBIOS name to IP addresses mapping UDP port 137,)
     
  2. datagram service (NetBIOS datagram delivery via UDP port 138)
     
  3. session service (point to point connection oriented NetBIOS sessions over TCP port 139, the traditional transport for SMB.)
     
  
  
• Communication endpoints are 16-bytes strings called NetBIOS names.
• Group names can be shared by multiple clients.
• SMB: Raw (naked) over TCP (port 445) or over NBT session service.