diff options
Diffstat (limited to 'misc-utils/blkid.8')
| -rw-r--r-- | misc-utils/blkid.8 | 299 |
1 files changed, 299 insertions, 0 deletions
diff --git a/misc-utils/blkid.8 b/misc-utils/blkid.8 new file mode 100644 index 0000000..dc1e68f --- /dev/null +++ b/misc-utils/blkid.8 @@ -0,0 +1,299 @@ +.\" Copyright 2000 Andreas Dilger (adilger@turbolinux.com) +.\" +.\" This man page was created for blkid from e2fsprogs-1.25. +.\" +.\" This file may be copied under the terms of the GNU Public License. +.\" +.\" Based on uuidgen, Mon Sep 17 10:42:12 2000, Andreas Dilger +.TH BLKID 8 "February 2011" "util-linux" "System Administration" +.SH NAME +blkid \- locate/print block device attributes +.SH SYNOPSIS +.B blkid +.RB \-L +.IR label " | " +.RB \-U +.IR uuid + +.B blkid +.RB [ \-dghlv ] +.RB [ \-c +.IR file ] +.RB [ \-o +.IR format ] +.in +6 +.RB [ \-s +.IR tag ] +.RB [ \-t +.IR NAME=value ] +[\fIdevice\fR ...] +.in -6 + +.B blkid +.RB -p +.RB [ \-O +.IR offset ] +.RB [ \-S +.IR size ] +.RB [ \-o +.IR format ] +.RB [ \-s +.IR tag ] +.in +9 +.RB [ \-n +.IR list ] +.RB [ \-u +.IR list ] +.IR device " ... " +.in -9 + +.B blkid +.RB -i +.RB [ \-o +.IR format ] +.RB [ \-s +.IR tag ] +.IR device " ... " + +.SH DESCRIPTION +The +.B blkid +program is the command-line interface to working with the +.BR libblkid (3) +library. It can determine the type of content (e.g. filesystem or swap) +that a block device holds, and also attributes (tokens, NAME=value pairs) +from the content metadata (e.g. LABEL or UUID fields). +.PP +.B blkid +has two main forms of operation: either searching for a device with a +specific NAME=value pair, or displaying NAME=value pairs for one or +more specified devices. +.SH OPTIONS +The \fIsize\fR and \fIoffset\fR arguments may be followed by the multiplicative +suffixes KiB=1024, MiB=1024*1024, and so on for GiB, TiB, PiB, EiB, ZiB and YiB +(the "iB" is optional, e.g. "K" has the same meaning as "KiB") or the suffixes +KB=1000, MB=1000*1000, and so on for GB, PB, EB, ZB and YB. +.TP +.BI \-c " cachefile" +Read from +.I cachefile +instead of reading from the default cache file (see CONFIGURATION FILE section +for more details). If you want to start with a clean cache (i.e. don't report +devices previously scanned but not necessarily available at this time), specify +.IR /dev/null . +.TP +.B \-d +Don't encode non-printing characters. The non-printing characters are encoded +by ^ and M- notation by default. Note that \fB-o udev\fR output format uses +a different encoding and this encoding cannot be disabled. +.TP +.B \-g +Perform a garbage collection pass on the blkid cache to remove +devices which no longer exist. +.TP +.B \-h +Display a usage message and exit. +.TP +.B \-i +Display I/O Limits (aka I/O topology) information. The 'export' output format is +automatically enabled. This option can be used together with the \fB-p\fR option. +.TP +.B \-l +Look up only one device that matches the search parameter specified with \fB-t\fR. +.TP +.B \-k +List all known filesystems and RAIDs and exit. +.TP +.B \-t +option. If there are multiple devices that match the specified search +parameter, then the device with the highest priority is returned, and/or +the first device found at a given priority. Device types in order of +decreasing priority are Device Mapper, EVMS, LVM, MD, and finally regular +block devices. If this option is not specified, +.B blkid +will print all of the devices that match the search parameter. +.TP +.BI \-L " label" +Look up the device that uses this filesystem \fIlabel\fR (equal to: -l -o device -t +LABEL=<label>). This lookup method is able to reliably use /dev/disk/by-label +udev symlinks (dependent on a setting in /etc/blkid.conf). Avoid using the +symlinks directly; it is not reliable to use the symlinks without verification. +The \fB-L\fR option works on systems with and without udev. + +Unfortunately, the original +.B blkid(8) +from e2fsprogs use the \fB-L\fR option as a +synonym for the \fB-o list\fR option. For better portability, use \fB-l -o device +-t LABEL=<label>\fR and \fB-o list\fR in your scripts rather than the \fB-L\fR option. +.TP +.BI \-n " list " +Restrict the probing functions to the specified (comma-separated) \fIlist\fR of +superblock types (names). +The list items may be prefixed with "no" to specify the types which should be ignored. +For example: +.sp + blkid -p -n vfat,ext3,ext4 /dev/sda1 +.sp +probes for vfat, ext3 and ext4 filesystems, and +.sp + blkid -p -n nominix /dev/sda1 +.sp +probes for all supported formats except minix filesystems. +This option is only useful together with \fB-p\fR. +.TP +.BI \-o " format" +Display +.BR blkid 's +output using the specified format. Note that the variables order and +devices order is variable. See also \fB-s\fR. The +.I format +parameter may be: +.RS +.TP +.B full +print all tags (the default) +.TP +.B value +print the value of the tags +.TP +.B list +print the devices in a user-friendly format; this output format is unsupported +for low-level probing (\fB-p\fR or \fB-i\fR). This output format is \fBDEPRECATED\fR +in favour of +.BR lsblk (8) +command. +.TP +.B device +print the device name only; this output format is always enabled for \fB-L\fR +and \fB-U\fR options +.TP +.B udev +print key="value" pairs for easy import into the udev environment; the keys are +prefixed by ID_FS_ or ID_PART_ prefixes + +The udev output returns the ID_FS_AMBIVALENT tag if more superblocks are detected, +and ID_PART_ENTRY_* tags are always returned for all partitions including empty +partitions. This output format is \fBDEPRECATED\fR. +.TP +.B export +print key=value pairs for easy import into the environment; this output format +is automatically enabled when I/O Limits (\fB-i\fR option) are requested +.RE +.TP +.BI \-O " offset" +Probe at the given \fIoffset\fR (only useful with \fB-p\fR). This option can be +used together with the \fB-i\fR option. +.TP +.BI \-p +Switch to low-level superblock probing mode (bypass cache). + +Note that low-level probing also returns information about partition table type +(PTTYPE tag) and partitions (PART_ENTRY_* tags). +.TP +.BI \-s " tag" +For each (specified) device, show only the tags that match +.IR tag . +It is possible to specify multiple +.B \-s +options. If no tag is specified, then all tokens are shown for all +(specified) devices. +In order to just refresh the cache without showing any tokens, use +.B "-s none" +with no other options. +.TP +.BI \-S " size" +Overwrite device/file size (only useful with \fB-p\fR). +.TP +.BI \-t " NAME" = "value" +Search for block devices with tokens named +.I NAME +that have the value +.IR value , +and display any devices which are found. +Common values for +.I NAME +include +.BR TYPE , +.BR LABEL , +and +.BR UUID . +If there are no devices specified on the command line, all block devices +will be searched; otherwise only the specified devices are searched. +.TP +.BI \-u " list " +Restrict the probing functions to the specified (comma-separated) \fIlist\fR of "usage" types. +Supported usage types are: filesystem, raid, crypto and other. The list items may be +prefixed with "no" to specify the usage types which should be ignored. For example: +.sp + blkid -p -u filesystem,other /dev/sda1 +.sp +probes for all filesystem and other (e.g. swap) formats, and +.sp + blkid -p -u noraid /dev/sda1 +.sp +probes for all supported formats except RAIDs. +This option is only useful together with \fB-p\fR. +.TP +.BI \-U " uuid " +Look up the device that uses this filesystem \fIuuid\fR. For more details see the \fB-L\fR option. +.TP +.B \-v +Display version number and exit. +.TP +.I device +Display tokens from only the specified device. It is possible to +give multiple +.I device +options on the command line. If none is given, all devices which +appear in +.I /proc/partitions +are shown, if they are recognized. +.SH "RETURN CODE" +If the specified token was found, or if any tags were shown from (specified) +devices, 0 is returned. + +If the specified token was not found, or no (specified) devices could be +identified, an exit code of 2 is returned. + +For usage or other errors, an exit code of 4 is returned. + +If the ambivalent low-level probing result was detected, an exit code of 8 is +returned. +.SH CONFIGURATION FILE +The standard location of the +.I /etc/blkid.conf +config file can be overridden by the environment variable BLKID_CONF. +The following options control the libblkid library: +.TP +.I SEND_UEVENT=<yes|not> +Sends uevent when +.I /dev/disk/by-{label,uuid,partuuid,partlabel}/ +symlink does not match with LABEL, UUID, PARTUUID or PARTLABEL on the device. Default is "yes". +.TP +.I CACHE_FILE=<path> +Overrides the standard location of the cache file. This setting can be +overridden by the environment variable BLKID_FILE. Default is +.I /run/blkid/blkid.tab +or +.I /etc/blkid.tab +on systems without /run direcotry +.TP +.I EVALUATE=<methods> +Defines LABEL and UUID evaluation method(s). Currently, the libblkid library +supports "udev" and "scan" methods. More than one methods may be specified in +a comma separated list. Default is "udev,scan". The "udev" method uses udev +.I /dev/disk/by-* +symlinks and the "scan" method scans all block devices from the +.I /proc/partitions +file. +.SH AUTHOR +.B blkid +was written by Andreas Dilger for libblkid and improved by Theodore Ts'o +and Karel Zak. +.SH AVAILABILITY +The blkid command is part of the util-linux package and is available from +ftp://ftp.kernel.org/pub/linux/utils/util-linux/. +.SH "SEE ALSO" +.BR libblkid (3) +.BR findfs (8) +.BR wipefs (8) |