From d7725fb45fe8d4fcb67cb9fbc117bc1cf66fcd56 Mon Sep 17 00:00:00 2001 From: Karel Zak Date: Tue, 17 Oct 2017 10:44:01 +0200 Subject: [PATCH 136/141] blkid: update man page about lsblk and ambivalent probing Upstream: http://github.com/karelzak/util-linux/commit/12786a901520d7b30ff75ee8727221bf8a3089cb Upstream: http://github.com/karelzak/util-linux/commit/27fbfef33c1f23b5448b6cee856bcb3500b33c42 Addresses: https://bugzilla.redhat.com/show_bug.cgi?id=1501953 Signed-off-by: Karel Zak --- misc-utils/blkid.8 | 39 +++++++++++++++++++++++++++------------ 1 file changed, 27 insertions(+), 12 deletions(-) diff --git a/misc-utils/blkid.8 b/misc-utils/blkid.8 index a974b8e99..1f12d202a 100644 --- a/misc-utils/blkid.8 +++ b/misc-utils/blkid.8 @@ -61,6 +61,23 @@ library. It can determine the type of content (e.g. filesystem or swap) that a block device holds, and also the attributes (tokens, NAME=value pairs) from the content metadata (e.g. LABEL or UUID fields). .PP +.B It is recommended to use +.BR lsblk (8) +.B command to get information about block devices, or lsblk --fs to get an overview of filesystems, or +.BR findmnt (8) +.B to search in already mounted filesystems. +.PP +.RS +.BR lsblk (8) +provides more information, better control on output formatting, easy to use in +scripts and it does not require root permissions to get actual information. +.B blkid +reads information directly from devices and for non-root users +it returns cached unverified information. +.B blkid +is mostly designed for system services and to test libblkid functionality. +.RE +.PP When .I device is specified, tokens from only this device are displayed. @@ -71,21 +88,19 @@ If none is given, all devices which appear in .I /proc/partitions are shown, if they are recognized. .PP -Note that -.B blkid -reads information directly from devices and for non-root users -it returns cached unverified information. It is better to use -.B lsblk --fs -to get a user-friendly overview of filesystems and devices. -.BR lsblk (8) -is also easy to use in scripts. -.B blkid -is mostly designed for system services and to test libblkid functionality. -.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. +.PP +For security reasons +.B blkid +silently ignores all devices where the probing result is ambivalent (multiple +colliding filesystems are detected). The low-level probing mode (\fB-p\fR) +provides more information and extra return code in this case. +It's recommended to use +.BR wipefs (8) +to get a detailed overview and to erase obsolete stuff (magic strings) from the device. .SH OPTIONS The \fIsize\fR and \fIoffset\fR arguments may be followed by the multiplicative suffixes like KiB (=1024), MiB (=1024*1024), and so on for GiB, TiB, PiB, EiB, ZiB and YiB @@ -264,7 +279,7 @@ identified, an exit code of 2 is returned. For usage or other errors, an exit code of 4 is returned. -If an ambivalent low-level probing result was detected, an exit code of 8 is +If an ambivalent probing result was detected by low-level probing mode (\fB\-p\fR), an exit code of 8 is returned. .SH CONFIGURATION FILE The standard location of the -- 2.13.6