XS Recommended Hardware: Difference between revisions

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(New page: {{translations}} {{OLPC}} Category:SchoolServer This is a description of the hardware recommended for the School server. Unlike the current laptop, the school server is currently ...)
 
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=Hardware known to work=
=Hardware known to work=


This hardware has been tested with the XS images - add your own, if possible with nots as to its suitability for the rule
This hardware has been tested with the XS images - add your own, if possible with notes as to its suitability for the rule


* HP/Compaq dx2250 - used by Martin Langhoff as test XS, low memory. Is RH-certified, and ships with a factory RH install.
* HP/Compaq dx2250 - used by Martin Langhoff as test XS, low memory. Is RH-certified, and ships with a factory RH install.
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* Smolt stats can be of use to see whether a particular HW is used in the field with Fedora systems - see the [http://smolt.fedoraproject.org stats page] - the [https://fedorahosted.org/smoltproject page] explains how it works.
* Smolt stats can be of use to see whether a particular HW is used in the field with Fedora systems - see the [http://smolt.fedoraproject.org stats page] - the [https://fedorahosted.org/smoltproject page] explains how it works.


=Hardware Profile==
==Processor==


* 1GHz+ x86 processor
==Network Interfaces==
* 1+ GB main memory
The following are the integrated networking interfaces on XS. Additional interfaces may be added to the system using the [[#Peripheral_Interfaces|peripheral interfaces]].
* Four to six USB interfaces, with power for three Marvell Wifi nodes and an external disk drive.
* One 300GB+ 3.5in SATA drive (500 GB makes more sense right now)
* Power and space for a second disk drive
* Two 100baseT network interfaces (one will do in some cases)
* Minimal fans
** replace them with heatsinks where possible
** easily replaceable
* Minimal openings in the case to avoid dust, etc
* Test it in the heat - should work in up to 50 deg C


===Wireless Mesh===
===Scaling up===
The School server will have two or three [[Active Antenna]], an 802.11b/g [http://en.wikipedia.org/wiki/Wi-Fi WiFi] wireless mesh networking interface. Each one of these serves as a mesh portal point operating on one of the three non-overlapping 802.11b channels (1, 6, and 11).


For larger schools, add RAM, disk storage and CPU (in that order).
While connected to the school servers using detachable five meter USB cables, the Active Antennas are considered integrated as there must always be at least one of these connected for proper server operation. In the future, higher numbers (four or five) of more advanced (directional) Active Antennas may be used.


==Environmental notes==
These are not integrated physically into the XS school server. This allows them to be located optimally for RF transmission/reception, while the server is in a more accessible location. It also allows for greater separation of the three antennas, operating simultaneously at neighboring frequencies.


The location where the HW will be deployed determines the environmental requirements. Our guidelines are as follows:
===Wired Networking===
Providing at least two [http://en.wikipedia.org/wiki/100baseT wired ethernet] interfaces allows for reliable, high-bandwidth connection between a [[school server]] and its internet connection (if through a [http://en.wikipedia.org/wiki/DSL DSL] or [http://en.wikipedia.org/wiki/Satellite_modem satellite modem]), other school servers, and any non-laptop computer equipment.


* Temperature: Should meet the same environmental specifications for temperature as the laptop. This is 50 C ambient.
The current plan for XS is to provide two [http://en.wikipedia.org/wiki/1000baseT 1000baseT] ports and four [http://en.wikipedia.org/wiki/100baseT 100baseT] ports on the server. The two high speed ports allow multiple servers in a school to form a high speed backbone, and the four additional ports on each server provide school network expansion without using external switches. External switches are not encouraged, due to unknown quality and the requirement of external power.
* Dust: For dusty environments, the hardware should be in an enclosure without vents, have no fans, and have protection for ports such as USB ports.
* Water, humidity: For humid environments the server should be capable of long-term operation in a constantly humid (100%) environment.
* Connectors and buttons should be resistant to water and dust intrusion. Buttons should be sealed against water, and connectors located and cables dressed to prevent water intrusion.


==Other considerations==
Each port will be provided with two LEDs indicating link status, simplifying network debugging.


* Mounting: the hardware should be able to run from a flat surface or be mounted on a wall and/or hangable.
==Peripheral Interfaces==
* Drop and Shake: should meet higher drop and shake specifications than standard consumer desktop PCs, to account for rough transport in the delivery.
The following peripheral interfaces are provided for expanding the capabilities of the school server.

===USB 2.0===
At least six [http://en.wikipedia.org/wiki/USB Universal Serial Bus] (USB) 2.0 interfaces should be provided for extending the storage and communication capabilities of a [[School server]].

This assumes that up to three external ports will be used for [[Active Antenna]], another for an external CD/DVD RW, another for a possible WAN connection, and one last one for temporary USB key or external USB drive attachment.

The total amount of power consumed by the USB devices will be clamped to 2.5 A at 5 Volts (12.5 W) total, aggregrated across all devices. Any single device may pull up to 1.5 A (7.5 W).

===PCI-Express Slot===
A short, full height PCI-Express (4 channel) expansion slot is provided internally in the XS. This slot is intended for the addition of a DVB-S receiver and demodulator, but may be used for other purposes as well.

The power consumption of this expansion slot limited to 15 W. Exceeding this will lower the maximum ambient operating temperature of the server, and may also prevent the use of a second disk drive.

==Non-Volatile Storage==
''to consider : how many drives are recommended for backups and replacement? with only 1 drive, what is the path to recovering a dead/dying drive? this may depend on quality of connection between server and upstream backup at a regional center''

===Internal Disk Drive===
One internal 3.5 in. disk drive will be provided. The disk interface will be SATA (version 1 or 2). The capacity of this disk drive WILL vary, with a minimum size of 300 GB at this time.

A second 3.5 in. disk drive will be supported in the XS, primarily for onsite drive replacement, but also allowing storage expansion. Use of a second disk drive will significantly increase the power consumption of the server.

A fan-less aluminum disk drive cooler may be worthwhile as a prevention of overheating measure.

===External Disk Drives===

Additional disks may be added using the external USB 2.0 ports.

===Flash===

A fair amount (512 MB) of NAND Flash (solid state non-volatile) memory will be provided on the XS server to allow the operating system and minimal services to continue operation even though the primary disk drive has failed.

A smaller amount (512KB) of NOR Flash will be provided for storage of configuration information and boot firmware.

On OTS systems Flash storage is currently not needed - or used. If you can obtain flash disks for all your OTS XS machines, do discuss it in the mailing list - it is an extremely valuable addition.we are considering using adding USB keys or SD cards to allow similar functionality.

==Power==

The power specifications of the [[School server]] are important. Many schools do not have adequate, or regular, power. While the power consumption should be minimized (30W is a good
target), consideration should be given to an integral (or optional modular) uninterruptible power supply (UPS). This is nothing more than a larger version of the laptop power supply!

In some test schools with minimal power, we are already deploying multiple (gang) battery chargers with integral UPS.

Possible methods of obtaining power are summarized in [[Battery_and_power]].

==Environmental==

===Temperature===
The [[school server]] should meet the same environmental specifications for temperature as the laptop. This is 50 C ambient.

===Water, Dust, and Salt Fog===

The server should be resistant to water spray from all directions, but does not have to survive immersion. It should be capable of long-term operation in a constantly humid (100%) environment, with salt fog and dust.

While the server will contain fans, they will externally accessible for easy replacement and under software control to conserve power.

Connectors and buttons should be resistant to water and dust intrusion. Buttons should be sealed against water, and connectors located and cables dressed to prevent water intrusion.

===Mounting===

While the school server should be designed to sit on a flat surface, it should probably
also be mountable (hangable) from a wall or post.

This shouldn't cause a problem unless the server includes batteries for a optional/modular UPS...

===Drop and Shake===

The [[school server]] should meet higher drop and shake specifications than standard consumer
desktop PCs, to account for rough transport in the delivery.


=XSX Specifications=
=XSX Specifications=

Revision as of 05:58, 23 July 2008

  Please copy/paste "{{Translationlist | xx | origlang=en | translated={{{translated}}}}}" (where xx is ISO 639 language code for your translation) to XS Recommended Hardware/translations HowTo [ID# 146889]  +/-  


  This page is monitored by the OLPC team.

This is a description of the hardware recommended for the School server. Unlike the current laptop, the school server is currently off-the-shelf (OTS) hardware. This document outlines general criteria for the School Server and has some specific notes about what we recommend for the XS.

Overview

Overall considerations

  • Known to be compatible with Fedora (Fedora 7 / Fedora 9) which is a modern Linux distribution.
  • Low power consumption
  • Operation in environmentally challenging conditions

Hardware known to work

This hardware has been tested with the XS images - add your own, if possible with notes as to its suitability for the rule

  • HP/Compaq dx2250 - used by Martin Langhoff as test XS, low memory. Is RH-certified, and ships with a factory RH install.
  • Laptop Dell Latitude D380 - used by Martin Langhoff as test XS.
  • Dell PowerEdge SC440 - used by Martin Langhoff as test XS.

As our work is based on a Fedora Linux, the Hardware compatibility notes for Fedora and RH systems is the best guide. See:

Hardware Profile=

  • 1GHz+ x86 processor
  • 1+ GB main memory
  • Four to six USB interfaces, with power for three Marvell Wifi nodes and an external disk drive.
  • One 300GB+ 3.5in SATA drive (500 GB makes more sense right now)
  • Power and space for a second disk drive
  • Two 100baseT network interfaces (one will do in some cases)
  • Minimal fans
    • replace them with heatsinks where possible
    • easily replaceable
  • Minimal openings in the case to avoid dust, etc
  • Test it in the heat - should work in up to 50 deg C

Scaling up

For larger schools, add RAM, disk storage and CPU (in that order).

Environmental notes

The location where the HW will be deployed determines the environmental requirements. Our guidelines are as follows:

  • Temperature: Should meet the same environmental specifications for temperature as the laptop. This is 50 C ambient.
  • Dust: For dusty environments, the hardware should be in an enclosure without vents, have no fans, and have protection for ports such as USB ports.
  • Water, humidity: For humid environments the server should be capable of long-term operation in a constantly humid (100%) environment.
  • Connectors and buttons should be resistant to water and dust intrusion. Buttons should be sealed against water, and connectors located and cables dressed to prevent water intrusion.

Other considerations

  • Mounting: the hardware should be able to run from a flat surface or be mounted on a wall and/or hangable.
  • Drop and Shake: should meet higher drop and shake specifications than standard consumer desktop PCs, to account for rough transport in the delivery.

XSX Specifications

OTS systems builders should aim for these XSX specs:

  • 1GHz+ x86 processor
  • 1+ GB main memory
  • Four to six USB interfaces, with power for three Marvell Wifi nodes and an external disk drive.
  • One 300GB+ 3.5in SATA drive (500 GB makes more sense right now)
  • Power and space for a second disk drive
  • Two 100baseT network interfaces (one will do in some cases)
  • Minimal fans
    • replace them with heatsinks where possible
    • easily replaceable
  • Minimal openings in the case to avoid dust, etc
  • Test it in the heat - should work in up to 50 deg C
  • Test the actual network performance

There are many hardware platforms meeting these specifications. We are working on a recommendation for a low power version.

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