| -a Attribute=Value |
Specifies the Attribute=Value pairs dependent on virtual file system type. To specify
more than one Attribute=Value pair, provide multiple -a Attribute=Value parameters. The following attribute or value pairs are specific to the Journaled
File System (JFS):
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- -a copy=Copy#
- Specifies which mirror copy to split off when used in conjunction
with the splitcopy attribute. The default
copy is the second copy. Valid values are 1, 2, or 3.
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- -a log=LVName
- Specifies the full path name of the filesystem logging logical
volume name of the existing log to be used. The log device for this
filesystem must reside on the same volume group as the filesystem.
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- -a size=NewSize
- Specifies the size of the Journaled File System. The size can
be specified in units of 512-byte blocks, megabytes or gigabytes.
If Value has the M suffix, it is interpreted to be in megabytes. If
Value has a G suffix, it is interpreted to be in gigabytes. If Value
begins with a +, it is interpreted as a request to increase the file
system size by the specified amount. If the specified size is not
evenly divisible by the physical partition size, it is rounded up
to the closest number that is evenly divisible.
The volume group
in which the file system resides defines a maximum logical volume
size and also limits the file system size.
The maximum size
of a JFS file system is a function of its fragment size and the nbpi value. These values yield the following size
restrictions: NBPI Minimum AG Size Fragment Size Maximum Size (GB)
512 8 512, 1024, 2048, 4096 8
1024 8 512, 1024, 2048, 4096 16
2048 8 512, 1024, 2048, 4096 32
4096 8 512, 1024, 2048, 4096 64
8192 8 512, 1024, 2048, 4096 128
16384 8 1024, 2048, 4096 256
32768 16 2048, 4096 512
65536 32 4096 1024
131072 64 4096 1024
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- -a splitcopy=NewMountPointName
- Splits off a mirrored copy of the file system and mounts it read-only
at the new mount point. This provides a copy of the file system with
consistent JFS meta-data that can be used for backup purposes. User
data integrity is not guaranteed, so it is recommended that file system
activity be minimal while this action is taking place. Only one copy
may be designated as an online split mirror copy.
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The following attribute or value pairs are specific
to the Enhanced Journaled File System (JFS2): |
| -a Attribute=Value |
- -a ea=v2
- Converts the JFS2 file system extended attribute (ea) format.
A JFS2 file system using the v1 format can be converted to one using
v2 format. After it is converted the file system cannot be converted
back to v1. The conversion is done in an on-demand manner such that
any extended attribute or ACL writes cause the conversion for that
file object to occur. The v2 format provides support for scalable
named extended attributes as well as support for NFS4 ACLs. The v1
format is compatible with prior releases of AIX®operating system.
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- -a efs=yes
- Converts a file system to an Encrypted File System (EFS).
The chfs command changes an existing file system into an EFS file
system. When the file system is EFS enabled, the ea attribute
is automatically converted to store scalable extended attributes (v2).
Restriction: The chfs commands prevents
conversion of the following file systems (mount points) to EFS because
the security infrastructures (kernel extensions, libraries and so
on) are not available during boot:
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- -a freeze = { timeout | 0 | off }
- Specifies that the file system must be frozen or thawed, depending
on the value of timeout. The act of freezing
a file system produces a nearly consistent on-disk image of the file
system, and writes all dirty file system metadata and user data to
the disk. In its frozen state, the file system is read-only, and anything
that attempts to modify the file system or its contents must wait
for the freeze to end. The value of timeout must be either 0, off, or a positive
number. If a positive number is specified, the file system is frozen
for a maximum of timeout seconds. If timeout is 0 or off, the file system will be thawed, and modifications can proceed.
Attention: Freezing base file systems (/, /usr, /var, /tmp) can result in unexpected behavior.
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- -a [ log | logname ]=LVName
-
Specifies the full path name of the filesystem logging logical
volume name of the existing log to be used. The log device for this
filesystem must reside on the same volume group as the filesystem.
Keyword INLINE can be used to specify that the log is in the logical
volume with the JFS2 file system. The file system must have been created
with an INLINE log to use this option. This option updates the /etc/filesystems file so that if the name of the logical volume
containing the file system changes the log will be recognized. Note: For a file system using OUTLINE log, this option can be used to change
the outline log from one logical volume to another logical volume
as long as the logical volume is properly formatted and the type of
the logical volume is jfs2log. If a file systems is mounted at the
time chfs is called to change the outline
log, the /etc/filesystems file will show
the change, but the actual log will not be changed until the next
mount for the file system (which follows a umount operation or a system crash and recovery). For a file system
using INLINE log, this option does not support switching logs between
INLINE and OUTLINE log. Currently, to switch from inlinelog to outlinelog
(or vise versa), the file system has to be removed and recreated.
In release AIX 5L™ and AIX 5.1, if the
file system is using inlinelog, the log entry is the same as the file
system in /etc/filesystems file: /j2.1:
dev = /dev/fslv00
vfs = jfs2
log = /dev/fslv00
mount = false
account = false
But, from AIX 5.2 and later releases,
if the file system is using inlinelog, the log entry is the keyword
INLINE in /etc/filesystems file: /j2.23:
dev = /dev/fslv04
vfs = jfs2
log = INLINE
mount = false
options = rw
account = false
If the file system was created
at AIX 5L or AIX 5.1, and later upgraded
to AIX 5.2 or later releases,
then chfs can be used to alter the inlinelog
name in /etc/filesystems file.
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- -a logsize=LogSize
- Specifies the size for an INLINE log in MBytes. The input size
must be a positive value. If the inline log size is greater than or
equal to 1, the input size must be an integer. If the input is floating
point value of less than 1 and greater than or equal to 0, the input
size is ignored and the default inline log size is taken. If value
begins with a + (plus sign), it is interpreted as a request to increase
the INLINE log size by the specified amount. If value begins with
a - (minus sign), it is interpreted as a request to reduce the INLINE
log size by the specified amount.
The input is ignored if an
INLINE log not being used. The INLINE log size cannot be greater
than 10% of the size of the file system and it cannot be greater than
2047 MB.
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- -a managed={yes | no}
- Enables Data Management Application Programming Interface (DMAPI)
on a JFS2 file system.
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- -a maxext=Value
- Specifies the maximum size of a file extent in file system blocks.
A zero value implies that the JFS2 default maximum should be used.
Values less than 0 or exceeding maximum supported extent size of 16777215
are invalid. Note that existing file extents are not affected by this
change.
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- -a mountguard={yes | no}
- Guards the file system against the unsupported concurrent mounts
in a PowerHA® or other clustering
environment. If the mountguard is enabled, the file system cannot
be mounted if it appears to be mounted on another node or system.
To temporarily override the mountguard setting, see the noguard option of the mount command.
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- -a options = mountOptions
- Specifies which mount option is passed
into the chfs command. For a list of the
valid options, refer to the mount command.
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- -a refreeze={timeout}
- Specifies that the timeout for a frozen file system be reset.
The timeout is reset to the value specified.
The file system must still be frozen (using the -a freeze option or the fscntl interface).
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- -a size=NewSize
- Specifies the size of the Enhanced Journaled File System in 512-byte
blocks, megabytes or gigabytes. If Value has the M suffix, it is interpreted
to be in megabytes. If Value has a G suffix, it is interpreted to
be in gigabytes. If Value begins with a +, it is interpreted as a
request to increase the file system size by the specified amount.
If Value begins with a -, it is interpreted as a request to reduce
the file system size by the specified amount.
If the specified
size does not begin with a + or -, but it is greater or smaller than
the file system current size, it is also a request to increase or
reduce the file system size.
If the file system has an inlinelog, the inlinelog size remains unchanged if the new size of this file system is the
same as the current file system size. If the specified size is not
evenly divisible by the physical partition size, it is rounded up
to the closest number that is evenly divisible. If the file system
is on a striped logical volume, the size of the new file system is
rounded to the nearest multiple of the striping width multiplied by
the physical partition size. The striping width is the number of hard
disks that form the striped logical volume.
This attribute
is required when creating a JFS2 file system unless the -d flag
has been specified. The volume group in which the file system resides
defines a maximum logical volume size and limits the file system size.
The maximum size is determined by the file system block size: fs block size (byte) MAX fssize (TB)
===========================================
512 4
1024 8
2048 16
4096 32
When a request to
reduce the file system size is successful, the logical volume should
be equal to or smaller than the original LV size depending on the
requested filesystem size.
Both size and logsize attributes can be specified
in one chfs request to resize the filesystem
and its inlinelog sizes.
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- -a vix={yes|no}
- Specifies whether the file system can allocate inode extents smaller
than the default of 16 KB if there are no contiguous 16 KB extents
free in the file system. After a file system is enabled for small
free extents, it cannot be accessed on earlier versions of AIX and the marking cannot
be removed.
- yes
- File system can allocate variable length inode extents.
- no
- File system must use default size of 16 KB for inode extents.
This has no effect if the file system already contains variable length
inode extents.
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Note: - JFS2 does not have nbpi or fragment size values to affect the
resulting size of the file system.
- You cannot shrink a file system if the requested size is less
that a physical partition size. At least one physical partition size
is asked to be reduced.
- Shrinking a file system that has snapshots is not allowed.
- During a shrink of the file system, writes to the file system
are blocked.
- During the period that the shrink or extend is running, the file
system is not accessible. Large file systems with inline logs might
not be usable for as long as several minutes. The inline log must
be completely reformatted.
- When the new file system size is specified, but its inlinelog size is NOT specified, the new logsize will be adjusted (extended/shrunk) proportionally,
based on the specified extended/shrunk file system size. The log size
increase or reduction should not be more than 40% of the file
system size increase or reduction.
- When a new file system size is not specified and there is an inlinelog, if a new logsize is specified, the file system size might be changed to include the
new log size.
- The freed space reported by the df command
is not necessary the space that can be truncated by a shrinkFS request due to filesystem fragmentation. A
fragmented filesystem may not be shrunk if it does not have enough
free space for an object to be moved out of the region to be truncated,
and shrinkFS does not perform filesystem
defragmentation. In this case, the chfs command should fail with the returned code 28 (ENOSPC)
- The maxext attribute is ignored in older
releases even if the filesystem was created with it on a later release.
|
| -A |
Specifies the attributes
for auto-mount. - yes
- File system is automatically mounted at system restart.
- no
- File system is not mounted at system restart.
|
| -d Attribute |
Deletes the specified
attribute from the /etc/filesystems file
for the specified file system. |
| -m NewMountPoint |
Specifies a new mount
point for the specified file system. |
| -n NodeName |
Specifies a node name
for the specified file system. The node name attribute in the /etc/filesystems file is updated with the new
name. The node name attribute is specific to certain remote virtual
file system types, such as the NFS (Network File System) virtual file
system type. |
| -p |
Sets the permissions for
the file system. - ro
- Specifies read-only permissions.
- rw
- Specifies read-write permissions.
|
| -t |
Sets the accounting attribute
for the specified file system. - yes
- File system accounting is to be processed by the accounting subsystem.
- no
- File system accounting is not to be processed by the accounting
subsystem; this is the default.
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| -u MountGroup |
Specifies the mount group.
Mount groups are used to group related mounts, so that they can be
mounted as one instead of mounting each individually. For example,
when performing certain tests, if several scratch file systems always
need to be mounted together, they can each be placed in the test mount group. They can then all be mounted with a single
command, such as the mount -t test command. |