HP-UX Reference (11i v2 03/08) - 4 File Formats (vol 8)

f
fs_vxfs(4) fs_vxfs(4)
fs_boffmask A mask value such that (byte_offset
& fs_boffmask) yields the offset from the
start of the nearest smaller block boundary.
fs_bshift The log base 2 of fs_bsize . Used to convert a byte offset into a block offset.
fs_bstart The offset, in blocks, of the first data block from the start of an allocation unit.
An allocation unit header may contain padding to align the first data block to a
specific boundary.
fs_checksum A checksum of the above fields. A macro,
VX_FSCHECKSUM, verifies or calcu-
lates the checksum.
fs_emap The offset, in blocks, of the free extent map (emap) from the start of an alloca-
tion unit.
fs_fbstart The offset, in blocks, of the first data block from the start of the file system.
fs_femap The offset, in blocks, of the first free extent map (emap) from the start of the file
system.
fs_fimap The offset, in blocks, of the first free inode map (imap) from the start of the file
system.
fs_iaddrlen The size, in blocks, of an indirect address block. An indirect address block is 8K
bytes. This field is set to (8K / fs_bsize ).
fs_imap The offset, in blocks, of the free inode map (imap) from the start of an allocation
unit.
fs_inopau The number of inodes in an allocation unit.
fs_inopb The number of inode entries per fs_bsize block in the inode list. The VxFS
inode is currently 256 bytes long.
fs_inoshift The log base 2 of fs_inopb. Used to convert an inode number into a block offset
in the inode list.
fs_maxtier The log base 2 of fs_aublocks.
fs_nindir The number of entries in an indirect address extent. An indirect address extent
is currently 8192 bytes in length, making the value for fs_nindir 2048.
The preceding fields are initialized when the file system is created and do not change unless the file sys-
tem is resized. These fields are replicated in each allocation unit header.
The following are additional fields which are dynamic:
fs_clean Set to VX_DIRTY when a file system is mounted for read/write access. Set to
VX_CLEAN on a umount or successful fsck. The file system cannot be
mounted for read/write access unless the fs_clean field is
VX_CLEAN.
fs_efree An array of the current number of free extents of each extent size in the file sys-
tem.
fs_firstlogid Initial log ID for when the file system is mounted.
fs_flags The following flags are recognized:
VX_FULLFSCK Set when a file system requires a full structural check to
recover from an error. If this flag is set, a full check is per-
formed after the replay recovery completes.
VX_NOLOG Set when the file system was mounted with the
VX_MS_NOLOG option. If this flag is set, then no log
replay recovery is performed.
VX_LOGBAD Set when an I/O error invalidated the log. If this flag is
set, no log replay recovery is performed.
VX_LOGRESET Set when the log ID runs over VX_MAXLOGID ( 2ˆ30 ).
The log ID is reset at the next appropriate time (such as a
mount or system sync).
VX_RESIZE Set when a file system resizing is in progress. If an fsck
detects this flag, it performs a resize recovery. See
HP-UX 11i Version 2: August 2003 − 2 − Hewlett-Packard Company Section 4−−57