lvm snapshot backups

snapbackups

#!/bin/env bash
#
# Restoring all snaps with PRESAMBA
# lvs -v | egrep PRESAMBA |awk '{print $1}'  > /tmp/findme \
#   && find /dev/centos | egrep -f /tmp/findme \
#   | xargs -n 1 lvconvert --merge
#  Delaying merge since origin is open.
#  Merging of snapshot centos/PRESAMBA___centos___home___day___20181106230701___1541545621 will occur on next activation of centos/home.
#  Delaying merge since origin is open.
#  Merging of snapshot centos/PRESAMBA___centos___root___day___20181106222001___1541542801 will occur on next activation of centos/root.
# reboot

export PATH=/bin:/sbin
set -e

SNAPPREFIX="mybackup"
THISSECOND=$(date +%s)
THISDATE=$(date +'%Y%m%d%H%M%S')
DONTSNAP="centos:swap centos:data"
SNAPSIZE="3GB"

function prunecorruptsnaps {
    echo "Checking for corrupt snapshots"
    lvs --separator : --noheadings --options vg_name,lv_name,lv_attr \
        | sed -e 's/^[ ]*//g' \
        | egrep ':....I.....$' \
        | awk -F: '{printf "/dev/%s/%s\n",$1,$2}' \
    | xargs -n 1 lvremove -f
}

function createsnaps {
    lvs --separator : --noheadings --options vg_name,lv_name,lv_attr \
        | sed -e 's/^[ ]*//g' > /tmp/newlvs

    awk -F: '{if ( $3 ~ /.w..ao....$/) {print $2,$1}}' < /tmp/newlvs | while read VOL GROUP
    do
        echo ${DONTSNAP} | fmt -1 | egrep -q "^${GROUP}:${VOL}$" && continue || true
        echo "Checking snapshots for ${GROUP}/${VOL}"
        for OPTIONS in \
             day:86400:7 \
             week:345600:4 \
             month:2678400:3
        do
            TIMETAG=$(echo ${OPTIONS} | cut -f1 -d:)
            GAPINSECONDS=$(echo ${OPTIONS} | cut -f2 -d:)
            HOWMANYTOKEEP=$(echo ${OPTIONS} | cut -f3 -d:)
            SNAPCMD="lvcreate -L ${SNAPSIZE} -s -n ${SNAPPREFIX}___${GROUP}___${VOL}___${TIMETAG}___${THISDATE}___${THISSECOND} /dev/${GROUP}/${VOL}"
            SNAPSTOREMOVE=$(egrep "^${GROUP}:*${SNAPPREFIX}___${GROUP}___${VOL}___${TIMETAG}___" /tmp/newlvs \
                | sort -n | head -n -${HOWMANYTOKEEP} \
                | awk -F: '{print $2}')
            for OLD in ${SNAPSTOREMOVE}
            do
                lvremove -f /dev/${GROUP}/${OLD}
            done
            OLDSNAPS=$(egrep "^${GROUP}:*${SNAPPREFIX}___${GROUP}___${VOL}___${TIMETAG}___" /tmp/newlvs | awk -F: '{print $2}')
            if [ "X${OLDSNAPS}" != "X" ]; then
                MOSTRECENT=$(echo ${OLDSNAPS} | fmt -1 | sed -e 's/.*___//g' | sort -n | tail -1)
                HOWLONGAGO=$(expr ${THISSECOND} - ${MOSTRECENT})
                if [ ${HOWLONGAGO} -gt ${GAPINSECONDS} ]; then
                    ${SNAPCMD}
                fi
            else
                ${SNAPCMD}
            fi
        done
    done
    rm /tmp/newlvs
}

prunecorruptsnaps
createsnaps