fs man page on Plan9

Man page or keyword search:  
man Server   549 pages
apropos Keyword Search (all sections)
Output format
Plan9 logo
[printable version]

FS(3)									 FS(3)

       fs - file system devices

       bind -b #k /dev

       The  fs	driver	builds	complex	 disk files out of simpler disk files.
       Inspired by the Plan 9 file server kernel's configuration  strings,  it
       provides	 device	 mirroring, partitioning, interleaving, and catenation
       for disk-based services like fossil(4) or venti(8).

       The device is intended to be bound at /dev  and	initially  contains  a
       directory  named fs, which in turn contains a ctl file and one file per
       configured device.

       Most control messages introduce a new device, here named new.  The file
       arguments are interpreted in the name space of the writing process.

       The  device  name new may be a single filename component (containing no
       slashes); in this case, the device is  created  under  #k/fs.   If  new
       instead	has  the  format  dir/file,  the  device  is made available at
       #k/dir/file.  The directory dir goes away when the last device on it is
       removed with the del control message, but #k/fs will never be removed.

       cat new files...
	      The device new corresponds to the catenation of files.

       inter new files...
	      The  device  new corresponds to the block interleaving of files;
	      an 8192-byte block size is assumed.

       mirror new files...
	      The device new corresponds to a RAID-1-like mirroring of	files.
	      Writes  to new are handled by sequentially writing the same data
	      to the files from right to left (the reverse of the order in the
	      control  message).   A  failed  write  causes  an eventual error
	      return but does not prevent the rest of the writes to the	 other
	      devices  of  the	mirror	set.   Reads  from  new are handled by
	      sequentially reading from the files from left to right until one
	      succeeds.	 The length of the mirror device is the minimum of the
	      lengths of the files.

       part new file offset length
       part new offset end
	      In the first form, the device  new  corresponds  to  the	length
	      units starting at offset in file.	 If offset+length reaches past
	      the end of file, length is silently reduced to fit.   Units  are
	      bytes.   In  the	second form, a previous disk request must have
	      defined the source file for further requests and the end of  the
	      device  is  determined by the end offset in the source file, and
	      not by the device length. Units are as defined in	 the  previous
	      disk request. This form is accepted for compatibility with fdisk
	      (in prep(8)) and sd(3) devices.

       del old
	      Removes the device named old.  The device	 will  still  be  seen
	      while  in	 use.	Further	 I/O  attempts will fail with an error
	      indication stating that the device is gone.  When old is	dir/*,
	      all devices under dir are removed.

       disk dir [ n file ]
	      makes  dir implicit in new device names (i.e., it makes new mean
	      dir/new by default).  Optional argument n specifies the  default
	      unit (sector) size in bytes and the default source file for fur‐
	      ther partition devices.  Default values are  restored  when  the
	      control file is closed.

       clear  Discard all fs device definitions.

       If  the variable fsconfig is set in plan9.ini(8), fs will read its con‐
       figuration from the file $fsconfig on the first attach.	This is useful
       when the machine boots from a local file server that uses fs.

       Use  a  previously  partitioned disk, /dev/sdC0, making partition files
       available under /dev/sdC0parts:

		   echo disk sdC0parts 512 /dev/sdC0/data
		   disk/fdisk -p /dev/sdC0/data
		   # now create plan 9 partitions
		   echo disk sdC0parts 512 /dev/sdC0parts/plan9
		   disk/prep -p /dev/sdC0parts/plan9
	      } > /dev/fs/ctl

       Mirror the two disks /dev/sdC0/data and /dev/sdD0/data  as  /dev/fs/m0;
       similarly, mirror /dev/sdC1/data and /dev/sdD1/data as /dev/fs/m1:

	      echo mirror m0 /dev/sdC0/data /dev/sdD0/data >/dev/fs/ctl
	      echo mirror m1 /dev/sdC1/data /dev/sdD1/data >/dev/fs/ctl

       Interleave the two mirrored disks to create /dev/fs/data:

	      echo inter data /dev/fs/m0 /dev/fs/m1 >/dev/fs/ctl

       Run kfs(4) on the interleaved device:

	      disk/kfs -f /dev/fs/data

       Save the configuration:

	      cp /dev/fs/ctl /dev/fd0disk

       To  load	 the  configuration  automatically  at	boot time, add this to


       read in cat(1), dd(1), sd(3), fossil(4), fs(8), plan9.ini(8),  prep(8),


       Mirrors	are RAID-like but not RAID.  There is no fancy recovery mecha‐
       nism and no automatic initial copying from a master drive to its mirror

       Each write system call on ctl may transmit at most one command.

                             _         _         _ 
                            | |       | |       | |     
                            | |       | |       | |     
                         __ | | __ __ | | __ __ | | __  
                         \ \| |/ / \ \| |/ / \ \| |/ /  
                          \ \ / /   \ \ / /   \ \ / /   
                           \   /     \   /     \   /    
                            \_/       \_/       \_/ 
More information is available in HTML format for server Plan9

List of man pages available for Plan9

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
Vote for polarhome
Free Shell Accounts :: the biggest list on the net