FreeBSD Study #9

In last Frieday, FreeBSD Study #9 was held in KDDI Web Commnications' Office.

大きな地図で見る

Today's session is "Managing storage on FreeBSD (vol.1)".

• What haappens between physical devices and /dev/* file on FreeBSD
  
  • GEOM is the framework to give abstract tiers between these
• GEOM class
• GEOM provider
• GEOM consumer
• sysctl kern.geom.*
• Sample for mirroring on GEOM
• File system of UNIX
  
  • Provide approches to file content via the file name
  • Tree structure with a single root
• Kernel does not necessarily need file systems
• Userland needs file systems
• UFS
  
  • default file system of FreeBSD
• Structure of UFS
  
  • inode
  • super block
  • how to approch the block content with inode
• fsck
  
  • Check where the inode is collapsed at
• SoftUpdates
  
  • Improve performance of fsck
  • Do I/O in async with strict order to add/delete block
• SoftUpdates + Jornal (SUJ)
  
  • Since FreeBSD 9.0, SoftUpdates support Journaling
  • Improve the performance more

In this day, Dr Hiroki Sato has explained about Filesystem, GEOM and UFS. I have understood what is UFS+SUJ. On next month, FreeBSD Study #10 will be held and this session will continue with the theme about ZFS.