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Index for Section 8 |
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Alphabetical listing for S |
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showfile(8)
NAME
showfile - displays the attributes of AdvFS files
SYNOPSIS
/usr/sbin/showfile [-x] filename...
OPTION
-x Displays the full storage allocation map (extent map) for AdvFS files.
OPERAND
filename...
One or more file names. If you do not supply a filename argument, use
an asterisk (*) to display the entire directory.
DESCRIPTION
The showfile command displays the attributes of one or more AdvFS files.
The command also displays the extent map of each file. An extent is a
contiguous area of disk space that the file system allocates to a file.
Simple files have one extent map; striped files have an extent map for
every stripe segment.
You can list AdvFS attributes for an individual file or the contents of a
directory. Although the showfile command lists both AdvFS and non-AdvFS
files, the command displays meaningful information for AdvFS files only.
The showfile command displays the following file attributes:
· Id
The unique number (in hexadecimal format) that identifies the file.
Digits to the left of the dot (.) character are equivalent to a UFS
inode.
· Vol
The location of primary metadata for the file, expressed as a number.
The data extents of the file can reside on another volume.
· PgSz
The page size in 512-byte blocks
· Pages
The number of pages allocated to the file
· XtntType
The extent type can be simple, which is a regular AdvFS file without
special extents; stripe, which is a striped file; symlink, which is a
symbolic link to a file; usf, nfsv3, and so on.
The showfile command cannot display attributes for symbolic links or
non-AdvFS files
· Segs
The number of stripe segments per striped file, which is the number of
volumes a striped file crosses. (Applies only to stripe type.)
· SegSz
The number of pages per stripe segment. (Applies only to stripe type.)
· I/O
The type of write requests to this file.
async
Write requests are buffered (the AdvFS default)
sync
Forced synchronous writes as described in chfile(8)
ftx Write requests executed under AdvFS transaction control, which is
reserved for metadata files and directories.
· Perf
The efficiency of file-extent allocation, expressed as a percentage of
the optimal extent layout. A high percentage, such as 100%, indicates
that the AdvFS I/O system has achieved optimal efficiency. A low
percentage indicates the need for file defragmentation.
Whereas a simple file has one extent map, a striped file has more than one
extent map. An extent map (numbered extentMap:1, extentMap:2, and so on)
displays the following information:
· pageOff
The starting page number of the extent
· pageCnt
The number of pages in the extent
· vol
The location of the extent, expressed as a number
· volBlock
The starting block number of the extent
· blockCnt
The number of blocks in the extent
· extentCnt
The number of extents
EXAMPLES
1. The following example displays the AdvFS-specific attributes for all
the files in the current working directory:
# showfile *
Id Vol PgSz Pages XtntType Segs SegSz I/O Perf File
6.8001 1 16 427 simple ** ** async 100% datafile1
7.8001 1 16 427 simple ** ** sync 100% datafile2
5.8001 1 16 1 simple ** ** ftx 100% quota.group
4.8001 1 16 1 simple ** ** ftx 100% quota.user
2. The following example shows the attributes and extent information for
the mail file, which is a simple file:
# showfile -x mail
Id Vol PgSz Pages XtntType Segs SegSz I/O Perf File
4198.800d 2 16 27 simple ** ** async 66% tutor
extentMap: 1
pageOff pageCnt vol volBlock blockCnt
0 5 2 781552 80
5 12 2 785776 192
17 10 2 786800 160
extentCnt: 3
SEE ALSO
advfs(4)