EFS Systems on a Linux Base: Getting Started

6 EFS Systems on a Linux Base: Getting Started

systems also work. Larger and faster systems may be needed for specific applications or

workloads.

1.4.1 System selection

A ThinkPad EFS system is appropriate for many tasks, such as:

򐂰 Education, for a single owner or as a server running a classroom of clients.

򐂰 Small development and testing, typically for a single person. Proof-of-concept work is

often in this category.

򐂰 Demonstrations, in many different ways.

In our opinion, a ThinkPad EFS system is not suitable as a production server. Key factors

are:

򐂰 Non-parity memory is used. This memory simply lacks the reliability of ECC memory.

򐂰 RAID protection is not available for the disks. Furthermore, reliable backup arrangements

(to tape, for example) are typically more difficult to provide in a ThinkPad environment.

򐂰 ThinkPads are not fully designed for continuous operation. Heat dissipation is a concern,

although a docking station helps in this area.

򐂰 Disk operation is considerably slower than that of a fast RAID array.

A properly configured xSeries EFS system is much more robust and is suitable as a

production server. Important factors include:

򐂰 ECC memory (or equivalent) is used. The importance of this for long-term stable operation

cannot be overstated.

򐂰 RAID disks are used and assumed in all xSeries EFS discussions. RAID 5 is typically

used and provides automatic protection against any single disk failure. A hot spare is

always recommended and is considered normal in larger configurations.

򐂰 Multiple, redundant power supplies are available for the approved xSeries servers and

provide N+1 protection.

򐂰 Tape connections are more likely to be available in this environment, making routine

backups more practical.

򐂰 An xSeries EFS system normally has at least two processors. One might be enabled for

S/390 emulation, leaving the other for all the Linux processes involved with S/390 I/O

emulation, LAN operation, and so forth. Multiple processors can be enabled for S/390

emulation, making a much faster system.

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The presence of ECC memory, RAID disk protection, and N+1 power supplies covers the vast

majority of typical PC failures—providing a very stable hardware platform.

Each platform has its place. The outstanding characteristic of the ThinkPad is its portability, of

course. A secondary factor is the ease of installation of a ThinkPad EFS system (assuming

use of an Ethernet LAN).

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This requires additional FLEX-ES license capabilities, with a corresponding increase in license fees.