This chapter focused on the various environments where iSCSI would be of value. In it we discussed SoHo (Small office, Home office) environments and where iSCSI fits in them.
Purchase software as part of the OS.
Purchase software from a local computer store.
Seldom share files.
Share files via e-mail or peer to peer.
Find iSCSI solutions useful for easily adding storage without opening systems.
Sometimes install specialty software, which often uses a database.
Sometimes have NAS servers.
Can use iSCSI to ease the impact of storage growth.
Find software iSCSI initiators and software-based iSCSI targets acceptable.
Are attracted to dual dialect servers. Midrange environments:
Use dedicated server systems to process their business needs.
Prefer HBAs instead of software iSCSI device drivers in their server systems.
Require their target storage controllers to have hardware iSCSI HBAs or chips to ensure maximum capacity and performance.
Have desktop and laptop systems that use software iSCSI device drivers.
Use dual dialect boxes. The size of the midrange market will be so large that the price of iSCSI adapters and chips will bring significant cost reductions to the iSAN market. iSCSI will tend to dominate the markets
At the midrange.
In the low end.
Over time in the high-end environment.
The high-end company has
A central computing location.
Backup tape drives.
Many storage controllers.
A campus made up of:
Many small fiefdoms of key managers who need to own their own systems.
Subenvironments that in many respects map to SoHo and midrange environments, including desktops and laptops.
At-distance installations. Satellite offices find that
VPNs and iSCSI are valuable technology partners.
They can access central storage as if it were located at the satellite location.
They will be able to operate in a manner similar to the operations of small offices and midrange companies.
They can have their own local iSCSI SANs with local storage.
They can have all their disk storage requirements coordinated with a central location.
They can use the central tape library for backup. The bigger the satellite office, the more it will function independently, but even a small office will have its logical SAN extend across VPNs to the central location. This will be especially true in metropolitan area networks (MANs). MANs will permit central iSCSI storage to be used as if it were local to the satellite location.
The high-end environment will be composed of "at-distance" environments:
These environments want access to devices such that tape can be located in some remote area (called tape vaulting).
Backup to tape at a remote location will be one of iSCSI's "killer apps." The central location holds all the big servers and big storage controllers.
This is the primary location for FC devices.
The key requirement is to ensure that iSCSI and Fibre Channel "work and play" well together.
A centralized technique is needed to
Manage the total storage environment.
Permit both Fibre Channel and iSCSI to work as a single transport network.
Fibre Channel is not going away, or at least not quickly.
iSCSI does not have to take on all FC deployments to be successful.
iSCSI will be considered a very successful transport if it can meet all the needs of SoHo and midrange environments.
Routers, gateways, and switches will permit access by campus systems to the FC storage in the central computing center.
Any amount of native iSCSI installation in the main computing center should be considered to be net added value to the iSCSI business plan.