table of contents
DEBUGVMFS(8) | vmfs-tools | DEBUGVMFS(8) |
NAME¶
debugvmfs - VMFS file system debuggerSYNOPSIS¶
debugvmfs VOLUME... COMMAND [ OPTIONS ]DESCRIPTION¶
The debugvmfs program allows to display various informations about VMFS file systems, and to access data within the file systems. The VOLUME to be opened can be either a block device or an image file. When the VMFS spreads accross several extents, all extents must be given. Please note that most commands are still likely to change in future versions.SPECIFYING FILES¶
Some commands take a filespec as an argument. A filespec may take either of the following forms:•A path name, relative to the root of the
filesystem if it starts with '/', or relative to the current working directory
otherwise (interactive mode only).
•An inode number, enclosed between angle brackets,
e.g. '<4>', '<0x1400004>'
COMMANDS¶
cat filespec [ ... ]Outputs the content of the given files from the
VMFS.
ls [ -l ] filespec
Lists files contained at the given location within the
VMFS.
With -l, gives some more information, much like the output from
ls(1) when given the -l option.
truncate filespec length
Truncate the file to the specified length. R/W support
must be enabled.
chmod filespec mode
Change file permissions to the given mode.
df
Outputs information about file system size.
get_file_block filespec position
Get file block corresponding to position in the specified
file.
check_vol_bitmaps
Checks volume bitmaps consistency.
show_heartbeats
Outputs active heartbeats on the file system.
read_block block_id [ ... ]
Outputs content within the specified block_id in
binary
get_block_status block_id
Get status (allocated or free) of the specified
block_id.
alloc_block_fixed block_id
Allocate the specified block_id. R/W support must be
enabled.
alloc_block block_type
Allocate a block of the specified type. R/W support must
be enabled.
Allowed block types are: 1 (File Block), 2 (Sub-Block), 3 (Pointer Block) and 4
(File Descriptor / Inode).
free_block block_id
Free the specified block_id. R/W support must be enabled.
Warning: can cause damage since no heartbeat is used at this time and a block
used by a file can be freed.
show
Display value(s) of the given variable. See the
VARIABLES section for more details. When no variable is given, it lists
the top-level properties.
shell
Starts an interactive session. All of the above commands
can be executed from within the interactive session.
The current working directory can be changed with the cd command,
followed by a filespec.
The following output redirections are supported within the shell:
• cmd > output
Puts the output of cmd in the output file.
• cmd >> output
Appends the output of cmd to the output file.
• cmd | external command
Sends the output of cmd to the input of external command. The
external command itself can contain output redirection.
Examples:
•read_block 0x00000681 | less
•cat /.fdc.sf | hexdump -C
•cat /.fdc.sf | hexdump -C > /tmp/fdc.hex
•cat /.fdc.sf | hexdump -C | less
VARIABLES¶
Variables in debugvmfs represent structures on the filesystem. The currently supported top-level variables are the following:• vol_version
• version
• label
• mode
• uuid
• ctime
• block_size
• subblock_size
• fdc_header_size
• fdc_bitmap_count
• fbb
• fdc
• pbc
• sbc
• fs
• lvm
• blkid[blk]
• dirent["path"]
• inode["filespec"]
The vol_version, version, label, mode, uuid,
ctime, block_size, subblock_size, fdc_header_size,
and fdc_bitmap_count properties are low-level information about the
filesystem.
The fbb, fdc, pbc and sbc variables are bitmaps.
Running them through the show command will display all the bitmaps
header fields. Each of these fields can also be displayed individually:
•
bitmap.items_per_bitmap_entry
• bitmap.bmp_entries_per_area
• bitmap.hdr_size
• bitmap.data_size
• bitmap.area_size
• bitmap.area_count
• bitmap.total_items
• bitmap.used_items
• bitmap.free_items
• bitmap.entry[n]
e.g. to display the data size of the fdc bitmap, type show fdc.data_size.
Each bitmap.entry[n] (where 0 ≤ n <
bitmap. bmp_entries_per_area * bitmap.area_count)
contains information about each entry in the bitmap. The available fields are:
• bitmap.entry[n].id
• bitmap.entry[n].total
• bitmap.entry[n].free
• bitmap.entry[n].ffree
• bitmap.entry[n].mdh
•
bitmap.entry[n].item[m]
The bitmap.entry[n].mdh is a metadata header. See further
below for more details about metadata headers.
Each bitmap.entry[n].item[m] (where 0 ≤
m < bitmap.items_per_bitmap_entry) contains
information about a given item in the given entry. The available fields are:
•
bitmap.entry[n].item[m].used
•
bitmap.entry[n].item[m].dump
The pbc bitmap has an additional field:
•
pbc.entry[n].item[m].blocks
The lvm variable contains low-level information about the physical and
logical volumes. The available fields are:
• lvm.uuid
• lvm.size
• lvm.blocks
• lvm.num_extents
• lvm.extent[n]
Each lvm.extent[n] (where 0 ≤ n <
lvm. num_extents) contains low-level information about the
physical volumes. The available fields are:
• lvm.extent[n].device
• lvm.extent[n].uuid
• lvm.extent[n].lun
• lvm.extent[n].version
• lvm.extent[n].name
• lvm.extent[n].size
•
lvm.extent[n].num_segments
•
lvm.extent[n].first_segment
•
lvm.extent[n].last_segment
Each blkid[blk] (where blk is a block id) contains
information on the given block id. The available fields are:
• blkid[blk].item
• blkid[blk].flags
Each dirent[path] (where path is a path relative to the
current directory in the shell or / outside the shell) contains information on
the directory entry corresponding to the given path. The available fields are:
•
dirent["path"].type
•
dirent["path"].block_id
•
dirent["path"].record_id
•
dirent["path"].name
Each inode[filespec] contains information on the inode
corresponding to the given filespec. The available fields are:
•
inode["filespec"].id
•
inode["filespec"].id2
•
inode["filespec"].nlink
•
inode["filespec"].type
•
inode["filespec"].flags
•
inode["filespec"].size
•
inode["filespec"].blk_size
•
inode["filespec"].blk_count
•
inode["filespec"].uid
•
inode["filespec"].gid
•
inode["filespec"].mode
•
inode["filespec"].zla
•
inode["filespec"].tbz
•
inode["filespec"].cow
•
inode["filespec"].atime
•
inode["filespec"].mtime
•
inode["filespec"].ctime
•
inode["filespec"].rdm_id
•
inode["filespec"].mdh
•
inode["filespec"].blocks
Metadata headers are being used in several places, such as
bitmap.entry[ n].mdh and
inode["filespec"].mdh. They mostly contain information
about clustered accesses to metadata on the filesystem. The available fields
are:
• mdh.magic
• mdh.pos
• mdh.hb_pos
• mdh.hb_lock
• mdh.hb_uuid
• mdh.hb_seq
• mdh.obj_seq
• mdh.mtime
Variable values can also be used in expressions using square brackets to use the
variable value as an index. For example:
•
blkid[inode["filespec"].id]
Enclosing a variable name with parentheses will use that variable value as a
variable name. For example:
•(blkid[blk].item).status
AUTHORS¶
Christophe Fillot < cf@utc.fr[1]>, Mike Hommey <mh@glandium.org[2]>SEE ALSO¶
vmfs-fuse(8)NOTES¶
- 1.
- cf@utc.fr
mailto:cf@utc.fr
- 2.
- mh@glandium.org
mailto:mh@glandium.org
03/25/2012 | 0.2.5.19.g4a80 |