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software:psion:file_system_paper [2008/05/14 17:54] – external edit 127.0.0.1software:psion:file_system_paper [2008/05/14 21:58] (current) – admin
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 Filesystem options for the Netbook Lx Filesystem options for the Netbook Lx
 ===== Issues ===== ===== Issues =====
-There are a number of filesystem issues brought up by the project requirements. +During the development of the Netbook LX some filesystem issues were brought up: 
- +  - A lot of stuff needs to be packed into the Nand flash 
-  - We need to pack a lot of stuff into the Nand flash +  - During development a CF needs to be used as the Root filesystem and this interacts badly with suspend/resume. 
-  - During development we need to use CF as the Root filesystem and this interacts badly with suspend/resume. +  - Whilst the machine won't be rebooted very often, long disk checks are not favorable and should be possibly avoided. 
-  -Whilst the machine won't be rebooted very often we don't want long disk checks if we can possibly avoid them +  - Both CF and Nand flash have quite limited numbers of max writes and the devices should remain working for years, rather than days or weeks.
-  - Both CF and Nand flash have quite limited numbers of max writes and we need things to remain working for years, rather than days or weeks.+
   - The system needs to be resistant to corruption when batteries go flat/power fails   - The system needs to be resistant to corruption when batteries go flat/power fails
-  - We need a way of integrating extra applications on CF or MMC with the base system on NAND+  - There should be a way of integrating extra applications on CF or MMC with the base system on NAND.
   - Users need to store their files and data somewhere.   - Users need to store their files and data somewhere.
-  - User data is really important and we must try not to lose it whatever happens +  - User data is really important and it should be highest priority not to lose it whatever happens. 
-  - Users will remove removable media when they feel like - we must cope gracefully, _always_+  - Users will remove removable media when they feel like - this should be dealt with gracefully, _always_
   - We can't easily change BooSt to read different filesystems   - We can't easily change BooSt to read different filesystems
   - We are expecting 20,000 warm boots but < 10 cold boots over 4 years.    - We are expecting 20,000 warm boots but < 10 cold boots over 4 years. 
  
-There are a number of different filesystems, bits of hardware, 'layout' issues and kernel issues which interact in a complicated fashion. This document describes the layout of the system that meets our needs, as worked out at the meeting of 2004.05.20. Background discussion on the hardware and fundamentals in now in [[File System Background]].+There are a number of different filesystems, bits of hardware, 'layout' issues and kernel issues which interact in a complicated fashion. This document describes the layout of the system that meets certain needs. Background discussion on the hardware and fundamentals in now in [[File System Background]].
  
 ===== Suggested set-ups ===== ===== Suggested set-ups =====
-Here are what seems to me to be plausible schemes for laying out our filesystems. Most issues are now resolved but will no doubt be a few wrinkles still to deal with. A picture is worth a thousand words so:+Here are what seems to be plausible schemes for laying out our filesystems. Most issues are now resolved but will no doubt be a few wrinkles still to deal with. A picture is worth a thousand words so:
  
 ==== Base System ==== ==== Base System ====
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 This means that we need to manage the appearance/removal of the apps on the CF in a seamless and user-friendly manner. This means that we need to manage the appearance/removal of the apps on the CF in a seamless and user-friendly manner.
  
-It is also an option to run a complete system from CF card, as we have done in development, working just like a laptop Drive. This allows the device to use standard Debian in it's entirety, but requires power management to work reliably with the CF (initial 2.4.19 support available week of 2004.05.24).+It is also an option to run a complete system from CF card, as we have done in development, working just like a laptop Drive. This allows the device to use standard Debian in it's entirety, but requires power management to work reliably with the CF (initial 2.4.19 support available since 2004.05.24).
  
 === Adding applications from removable media === === Adding applications from removable media ===
software/psion/file_system_paper.txt · Last modified: 2008/05/14 21:58 by admin