NAME

setfa - Sets file attributes

SYNOPSIS

setfa [ -A allocahead[k|m|g] ] [ -B] [ -d] [ -D] [ -f]

[ -g stripe_group ] [ -l length[k|m|g] ] [ -L length[k|m|g] ]

[ -q] [ -r dirname ] [ -s stripe ] [ -V] filename …

AVAILABILITY

SUNWsamfs

DESCRIPTION

The setfa command sets attributes for a new or existing file. The file is created if it does not already exist.

When file attributes are set on a directory, files and directories subsequently created in that directory inherit those attributes.

OPTIONS

This command accepts the following options:

-A allocahead

Specifies the number of bytes to be allocated ahead of a write to the file. The n must be an integer and must be greater than or equal to one kilobyte and less than 4 terabytes. The n is rounded down to units of kilobytes. The integer specified may be followed by k (for kilobytes), m (for megabytes), or g (for gigabytes). For example:

-A 1m

This option is only valid for a regular file. This option should be used when writing large files where more sequential allocation is desired. Note, when the file is closed the blocks are reset to the size of the file.

-B

Permanently clears the direct I∕O attribute for this file. This means that data is transferred indirectly between the user's buffer and disk through the system's buffer cache.

For more information, see the directio (3C) man page. The Oracle HSM buffered I∕O attribute is persistent, remaining until the attribute is reset or the file is destroyed.

-d

Resets all file attributes to the default attributes. When -d is specified, attributes are first reset to the default, then other attribute-setting options are processed.

-D

Permanently sets the direct I∕O attribute for this file. This means that data is transferred directly between the user's buffer and disk. This attribute should only be set for large, block-aligned, sequential I∕O. The default I∕O mode is buffered (uses the page cache). Direct I∕O is not used if the file is currently memory mapped.

For more information, see the directio (3C) man page. The Oracle HSM direct I∕O attribute is persistent, remaining until the attribute is reset or the file is destroyed.

-f

Supresses errors.

-g stripe_group

Specifies the number of the striped group in which the file is to be allocated first. For stripe_group, specify a number such that 0 ≤ stripe_group ≤ 127 and is a stripe group defined in the file system. If round-robin is set (see the -s option), the file is completely allocated on the designated stripe group.

Note that the stripe_group attribute is inherited. It is possible to create a directory and set a stripe group for that directory. Then, all files created in that directory are allocated on the specified stripe group. In the following example, files created in audio are allocated on striped group 0, and files created in video are allocated on stripe group 1:

setfa -g 0 -s 0 audio
setfa -g 1 -s 0 video

-l length

Specifies the number of bytes to be preallocated to the file. This can be specified only for a file with no disk blocks assigned. This option is ignored for a directory. If an I∕O event attempts to extend a preallocated file, the caller receives an ENXIO error. If an attempt is made to preallocate a file with disk blocks assigned, or a segmented file, the caller receives an EINVAL error.

-L length

Specifies the number of bytes to be preallocated to the file. The n must be an integer. The integer specified may be followed by k (for kilobytes), m (for megabytes), or g (for gigabytes). For example:

-L 1g

This option is only valid for a regular file. The L option allocates using standard allocation. This means striping is supported. This also means the file can be extended. The L and l options are mutually exclusive.

-q

Specifies that this file will be linked to the pseudo character device driver, samaio, for the purpose of issuing async I∕O. Note, this option also sets Direct I∕O and qwrite. Setting this option may result in greater performance. This option is not valid when applied against certain system files and directories such as lost+found.

-r dirname

Recursively performs the operation (setting file attributes) for any files contained in the specified dirname or its subdirectories. If no filename is specified, a -r dirname must be specified.

-s stripe

Specifies the number of allocation units to be allocated before changing to the next unit. If stripe is 1, the file is striped across all units with 1 disk allocation unit (DAU) allocated per unit. If stripe is 0, the file is allocated on one unit until that unit has no space. The default stripe is specified when the file system is mounted. For more information, see mount_samfs (1m)).

An Invalid argument message is generated if a stripe 0 is specified and mismatched stripe groups exist. A stripe group is said to be mismatched if all striped groups do not have the same number of partitions. Striping across mismatched stripe groups is not allowed.

-V

Enables the verbose display. A message is written for each file on which attributes are set.

filename

Specifies the file for which attributes are being set. If no -r dirname is specified, a filename must be specified. If -r dirname is specified, a filename specification is optional.