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docs:techref:filesystems [2023/05/05 08:43] – [ext2] adds comment about ext3/4 journaling joshendersdocs:techref:filesystems [2024/03/09 03:22] (current) – [Filesystems] add link to intro palebloodsky
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 ====== Filesystems ====== ====== Filesystems ======
  
-This article is about file systems in the OpenWrt installation on built-in flash. +This article is about file systems used by OpenWrt for device built-in flash.
-For general external support for installing file systems on other devices, including partitioning and mounting see [[docs:guide-user:storage:start|this page about general storage]].+
  
-Please read about the -> [[flash.layout]] as well. Also, note that there are two types of flash memory: [[wp>Flash_memory#NOR_flash|NOR flash]] and [[wp>Flash_memory#NAND_flash|NAND flash]]. Also, you should read up on ''[[docs:techref:mtd]]''. +For installing additional file systems, including partitioning and mounting, see this page for [[docs:guide-user:storage:start|general storage]] as well as this page to other common [[:docs:guide-user:storage:filesystems-and-partitions|filesystems]]. 
 + 
 +Please read about the [[flash.layout]] as well. Also, note that there are two types of flash memory: [[wp>Flash_memory#NOR_flash|NOR flash]] and [[wp>Flash_memory#NAND_flash|NAND flash]]. See also [[docs:techref:mtd]]. 
  
 ===== Common File System ===== ===== Common File System =====
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 ==== tmpfs ==== ==== tmpfs ====
-  * [[wp>tmpfs]]+[[wp>tmpfs]] is implemented on many Unix-like operating systems (including OpenWrt). It operates similar to a RAM-Disk, without writing files to disk. In OpenWrt, ''/tmp'' resides on a tmpfs-partition and ''/var'' is a symlink to it; ''/dev'' resides on a little tmpfs partition of its own. 
   * [[https://www.kernel.org/doc/html/latest/filesystems/tmpfs.html|Kernel documentation on tmpfs]]   * [[https://www.kernel.org/doc/html/latest/filesystems/tmpfs.html|Kernel documentation on tmpfs]]
-  * ''/tmp'' resides on a tmpfs-partition and ''/var'' is a symlink to it; ''/dev'' resides on a little tmpfs partition of its own + 
-  * (+) no wear leveling+  * (+) doesn't directly use space on non-volatile storage 
 +  * (-) no wear leveling
   * (-) volatile (doesn't survive a reboot)   * (-) volatile (doesn't survive a reboot)
  
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   * (+) is compressed, so a program (which is preinstalled) takes much less space, so effectively you have more space   * (+) is compressed, so a program (which is preinstalled) takes much less space, so effectively you have more space
  
-It was replaced with UBIFS.+For NAND-flash targets, it was replaced with UBIFS.
  
 ==== UBIFS ==== ==== UBIFS ====
  • Last modified: 2023/05/05 08:43
  • by joshenders