advfs(4)advfs(4)NAMEadvfs - 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 performance,
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 sys‐
tem is available as a separately licensed product: The AdvFS Utilities.
These utilities include capabilities such as adding volumes without
reconfiguring the directory hierarchy of the file system, cloning file‐
sets 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 fea‐
tures 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 file‐
sets can span all volumes in the domain.
AdvFS File System Concepts
AdvFS introduces file system concepts that do not exist for UFS. Under‐
standing 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 con‐
figured with the Logical Storage Manager (LSM). Domain
A 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 domain using the mkfdmn command, you must
specify a domain name and one initial volume. The mkfdmn com‐
mand creates a subdirectory in the /etc/fdmns directory for each
new domain. The domain subdirectory contains a symbolic link to
the initial volume.
If you have AdvFS Utilities, you can add additional volumes to
an existing domain by using the addvol utility. With each added
volume, the addvol utility creates a new symbolic link in the
appropriate 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
composed of one or more volumes.
An Advanced File System consists of a 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 fileset.
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 origi‐
nal 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 domain list Get the AdvFS attributes of a file Obtain a list of
all the filesets in an AdvFS 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 file‐
set. See chfsets(8). Changes the attributes of a volume. See
chvol(8). Makes the files in a domain more contiguous. See defrag‐
ment(8). Edits the user or group quotas. See edquota(8). Checks and
repairs corrupted AdvFS domains. See fixfdmn(8). Creates a new
domain. See mkfdmn(8). Creates a fileset within an existing 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 consis‐
tency. See quotacheck(8). Turns off user and group quotas. See quo‐
taoff(8). Turns on user and group quotas. See quotaon(8). Renames an
existing fileset. See renamefset(8). Summarizes the disk usage and
quotas for specified filesets. See repquota(8). Removes an unused
domain from AdvFS. See rmfdmn(8). Deletes a fileset from a domain. See
rmfset(8). Recovers file data from damaged AdvFS domains. See sal‐
vage(8). Takes a snapshot of an AdvFS domain's metadata. See
savemeta(8). Displays unformatted disk blocks. See shblk(8). Displays
frag file information. See shfragbf(8). Displays 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 domain. See
switchlog(8). Prints the path name of a file, given the tag number.
See tag2name(8). Displays disk information for AdvFS domains and file‐
sets. See vdf(8). Backs up filesets. See vdump(8). Checks for and
repairs file system inconsistencies. See verify(8). Displays pages of
an AdvFS file. See verify(8). Restores files from devices written with
the vdump command. See vrestore(8). Displays a page from a storage
bitmap (SBM) file. See verify(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.
Also available with the AdvFS Advanced Utilities license is support for
data management applications through the Data Management Applications
Programming Interface (DMAPI). See the DMAPI manpage for details.
The following list summarizes the AdvFS Utilities commands: Adds a vol‐
ume to an existing 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 file‐
set. See clonefset(8). Accesses the Data Management Applications Pro‐
gramming Interface (DMAPI). See dmapi(3). Starts the AdvFS graphical
user interface. See dtadvfs(8). Runs the Logical Storage Manager
Storage Administrator (LSMSA). See lsmsa(8). Moves the location of a
file within a 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 mktrash‐
can(1). Removes a volume from an existing domain. See rmvol(8). Shows
the trashcan directory, if any, that is attached to a specified direc‐
tory. See mktrashcan(1). Interleaves storage allocation of a file
across two or more volumes within a domain. See stripe(8).
RESTRICTION
When configuring root on AdvFS, set up one partition and one fileset in
the domain. Multiple volumes are not supported on root (except for a
cluster root).
EXAMPLE
The following example creates a domain called accounts_dmn, which con‐
tains dsk1c as the initial volume. The example also creates two file‐
sets, credit_fs and debit_fs, creates mount point directories, 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 -tadvfs accounts_dmn#credit_fs
/mnt/credit # mount -tadvfs accounts_dmn#debit_fs /mnt/debit
SEE ALSO
Commands: mkdir(1), mkfdmn(8), mkfset(8), mount(8), showfdmn(8), showf‐
sets(8), showfile(8)
Functions: dmapi(3)
Files: advfs_err(4), fdmns(4)advfs(4)