advfs(4)						     Kernel Interfaces Manual							  advfs(4)

NAME

       advfs - A local file system and utilities

DESCRIPTION

       The  Advanced  File System (AdvFS), the file system default on the Tru64 UNIX operating system, features rapid crash recovery, high perfor-
       mance, and a flexible structure that enables you to manage your file system while it is on line. AdvFS  is licensed  with  the  Tru64  UNIX
       operating system.

       A  set  of utilities that expands the capabilities of the AdvFS file system is available as a separately licensed product: The AdvFS Utili-
       ties. These utilities include capabilities such as adding volumes without reconfiguring the directory hierarchy of the file system, cloning
       filesets  to enable online backup, improving system performance with domain balancing, and file striping.  A graphical user interface (GUI)
       that simplifies file system management is available with the utilities.

       Using journaling techniques, AdvFS provides faster crash recovery than the UNIX File System (UFS), which implements  crash  recovery  using
       the fsck utility.

       In addition to fast restarts, AdvFS ensures that file structures are recovered consistently; extends file and fileset sizes to greater than
       2 gigabytes; creates, deletes, and renames files faster than UFS; and provides enhanced	local  and  remote  backup  utilities  (vdump  and
       rvdump, vrestore and rvrestore).

       By  configuring	AdvFS  as  the root file system, the preceding AdvFS features are extended to the root file system.  You can configure the
       AdvFS as the root file system during system installation.

       A UFS file system corresponds to a disk partition and is, therefore, limited by the size restrictions of  that  disk.  In  contrast,  AdvFS
       filesets can span all volumes in the file domain.

   AdvFS File System Concepts
       AdvFS  introduces file system concepts that do not exist for UFS. Understanding the following concepts prepares you for planning, creating,
       and maintaining the AdvFS file system: Volumes

	      A volume is any mechanism that behaves like a UNIX block device, such as a disk, disk partition, or logical volume that  is  config-
	      ured with the Logical Storage Manager (LSM).  File Domain

	      A  file  domain  is  a  named  set of one or more volumes that provides a shared storage pool for one or more filesets (see filesets
	      below).

	      When you create a file domain using the mkfdmn command, you must specify a domain name and one initial volume.  The  mkfdmn  command
	      creates  a  subdirectory in the /etc/fdmns directory for each new file domain. The file-domain subdirectory contains a symbolic link
	      to the initial volume.

	      If you have AdvFS Utilities, you can add additional volumes to an existing file domain by using the addvol utility.  With each added
	      volume,  the  addvol  utility  creates  a new symbolic link in the appropriate file-domain subdirectory of the /etc/fdmns directory.
	      Filesets

	      A UFS file system has exclusive use of the volume that contains it; an AdvFS fileset can be one of several in a domain that is  com-
	      posed of one or more volumes.

	      An Advanced File System consists of a file domain with at least one fileset that you create using the mkfset command. A fileset is a
	      mountable entity.  Clone Fileset

	      A clone fileset is a read-only copy of an existing fileset, which you can mount as you do other filesets. You create a clone fileset
	      by using the clonefset utility. The reason you create and mount a clone fileset is to perform an online backup of the existing file-
	      set.

	      A clone fileset is a snapshot of the original fileset, capturing and fixing the original fileset at a moment in time.   Any  changes
	      you  make  to the original fileset will not appear in its clone. Changes to data in files in the original fileset will not appear in
	      the clone. Also, files that you remove from the original fileset will remain accessible in the clone under the names they  had  when
	      you created the clone fileset.

   AdvFS Application Programming Interface
       With  the  release  of  Tru64 UNIX Version 5.0, there is an application programming interface (API) for AdvFS. Customers can use the API to
       build customized backup and restore capabilities. The API consists of several base system functions, which are described in  the  following
       reference  pages:  Create  a  read-only copy of an active fileset Get an AdvFS file domain list Get the AdvFS attributes of a file Obtain a
       list of all the filesets in an AdvFS file domain Obtain fileset quotas for an AdvFS fileset Remove a fileset or a clone fileset	Set  AdvFS
       file attributes Set fileset quotas for an AdvFS fileset

   AdvFS Commands in the Base System
       The  following  list summarizes the AdvFS commands that are included in the base system: Displays file system statistics. See advfsstat(8).
       Locates AdvFS partitions on disks. See advscan(8).  Changes the attributes of a file. See chfile(8).  Changes the attributes of a  fileset.
       See  chfsets(8).   Changes  the attributes of a volume. See chvol(8).  Makes the files in a file domain more contiguous. See defragment(8).
       Edits the user or group quotas.	See edquota(8).  Creates a new file domain.  See mkfdmn(8).  Creates a fileset	within	an  existing  file
       domain.	See mkfset(8).	Checks for mounted AdvFS filesets. See mountlist(8).  Creates a list of files on specified filesets, including the
       path names and i-numbers.  See ncheck(8).  Displays formatted BMT pages.  See nvbmtpg(8).  Displays formatted frag pages.  See nvfragpg(8).
       Displays formatted log pages.  See nvlogpg(8).  Displays formatted tag pages.  See nvtagpg(8).  Summarizes fileset ownership.  See quot(8).
       Displays disk usage and limits.	See quota(1).  Checks file system quota consistency. See quotacheck(8).  Turns on user and  group  quotas.
       See  quotaon(8).  Turns off user and group quotas.  See quotaoff(8).  Renames an existing fileset.  See renamefset(8).  Summarizes the disk
       usage and quotas for specified filesets.  See repquota(8).  Removes an unused file domain from AdvFS. See  rmfdmn(8).   Deletes	a  fileset
       from a file domain. See rmfset(8).  Displays unformatted disk blocks. See shblk(8).  Displays frag file information. See shfragbf(8).  Dis-
       plays domain attributes.  See showfdmn(8).  Displays attributes for AdvFS files. See showfile(8).  Displays information about the  filesets
       in a domain. See showfsets(8).  Moves the AdvFS log file to a different volume in a file domain. See switchlog(8).  Prints the path name of
       a file, given the tag number. See tag2name(8).  Displays mcells that describe metadata for a file. See vbmtchain(8).  Displays a  formatted
       page of the bitfile metadata table (BMT). See vbmtpg(8).  Backs up filesets. See vdump(8).  Checks for and repairs file system inconsisten-
       cies. See verify(8).  Displays the contents of a file from an unmounted domain. See vfile(8).  Prints a single header page of a frag  file.
       See vfragpg(8).	Displays a formatted page of the log. See vlogpg(8).  Displays the logical sequence number (LSN) of a page of the log. See
       vlsnpg(8).  Restores files from devices written with the vdump command. See vrestore(8).  Displays a formatted page of the  tag	directory.
       See vtagpg(8).

   AdvFS Utilities
       The  AdvFS  Utilities  are  licensed and purchased separately from the Tru64 UNIX operating system. However, the software and the reference
       pages for them are installed when you install the base system.  You must activate a Product Authorization Key to activate the Advanced File
       System  Utilities.  The	following  list  summarizes the AdvFS Utilities commands: Adds a volume to an existing file domain. See addvol(8).
       Starts the AdvFS graphical user interface (GUI) daemon.	Balances the percentage of used space between volumes. See balance(8).	Creates  a
       read-only  copy	of a fileset. See clonefset(8).  Starts the AdvFS graphical user interface.  See dtadvfs(8).  Moves the location of a file
       within a file domain.  See migrate(8).  Attaches directories to a trashcan directory,  which  stores  deleted  files.   See  mktrashcan(1).
       Detaches  a specified directory from a trashcan directory. See mktrashcan(1).  Removes a volume from an existing file domain. See rmvol(8).
       Shows the trashcan directory, if any, that is attached to a specified directory. See mktrashcan(1).  Interleaves storage  allocation  of  a
       file across two or more volumes within a file domain.  See stripe(8).

RESTRICTION

       When configuring root on AdvFS, set up one partition and one fileset in the file domain. Multiple volumes are not supported on root (except
       for a cluster root).

EXAMPLE

       The following example creates a file domain called accounts_dmn, which contains dsk1c as the initial volume.  The example also creates  two
       filesets, credit_fs and debit_fs, and mounts both filesets.  # mkfdmn /dev/disk/dsk1c accounts_dmn # mkfset accounts_dmn credit_fs # mkfset
       accounts_dmn  debit_fs  #  mkdir  /mnt/credit  /mnt/debit  #  mount  -t	advfs  accounts_dmn#credit_fs  /mnt/credit  #	mount	-t   advfs
       accounts_dmn#debit_fs /mnt/debit

SEE ALSO

       Commands: mkdir(1) ,fdmns(4), mkfdmn(8), mkfset(8), mount(8)

       Files: advfs_err(4)

																	  advfs(4)