Files
percona-toolkit/lib/bash/safeguards.sh
2012-01-13 10:02:17 -07:00

81 lines
2.9 KiB
Bash

# This program is copyright 2011 Percona Inc.
# Feedback and improvements are welcome.
#
# THIS PROGRAM IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
# WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
# MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
#
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free Software
# Foundation, version 2; OR the Perl Artistic License. On UNIX and similar
# systems, you can issue `man perlgpl' or `man perlartistic' to read these
# licenses.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, write to the Free Software Foundation, Inc., 59 Temple
# Place, Suite 330, Boston, MA 02111-1307 USA.
# ###########################################################################
# safeguards package
# ###########################################################################
# Package: safeguards
# safeguards is a collection of function to help avoid blowing things up.
set -u
disk_space() {
local filesystem="${1:-$PWD}"
# Filesystem 1024-blocks Used Available Capacity Mounted on
# /dev/disk0s2 118153176 94409664 23487512 81% /
df -P -k "$filesystem"
}
# Sub: check_disk_space
# Check if there is or will be enough disk space. Input is a file
# with output from <disk_space()>, i.e. `df -P -k`. The df output
# must use 1k blocks, but the mb arg from the user is in MB.
#
# Arguments:
# file - File with output from <disk_space()>.
# mb - Minimum MB free.
# pc - Minimum percent free.
# mb_margin - Add this many MB to the real MB used.
#
# Returns:
# 0 if there is/will be enough disk space, else 1.
check_disk_space() {
local file="$1"
local mb="${2:-0}"
local pc="${3:-0}"
local mb_margin="${4:-0}"
# Convert MB to KB because the df output should be in 1k blocks.
local kb=$(($mb * 1024))
local kb_margin=$(($mb_margin * 1024))
local kb_used=$(cat "$file" | awk '/^\//{print $3}');
local kb_free=$(cat "$file" | awk '/^\//{print $4}');
local pc_used=$(cat "$file" | awk '/^\//{print $5}' | sed -e 's/%//g');
if [ "$kb_margin" -gt "0" ]; then
local kb_total=$(($kb_used + $kb_free))
kb_used=$(($kb_used + $kb_margin))
kb_free=$(($kb_free - $kb_margin))
pc_used=$(awk "BEGIN { printf(\"%d\", $kb_used/$kb_total * 100) }")
fi
local pc_free=$((100 - $pc_used))
if [ "$kb_free" -le "$kb" -o "$pc_free" -le "$pc" ]; then
warn "Not enough free disk space: ${pc_free}% free, ${kb_free} KB free; wanted more than ${pc}% free or ${kb} KB free"
return 1
fi
return 0
}
# ###########################################################################
# End safeguards package
# ###########################################################################