use btrfs-send for data syncing, testing still in progress

[distro-setup] / btrbk-run

diff --git a/btrbk-run b/btrbk-run
index 4f4739d954e39d33c423ea59d06e174244893316..05589d1c8626391454b9e0cf261e4196d4e52a1e 100755 (executable)
--- a/btrbk-run
+++ b/btrbk-run
@@ -1,4 +1,4 @@
-#!/bin/bash -l
+#!/bin/bash
 
 set -eE -o pipefail
 trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
@@ -11,10 +11,15 @@ usage() {
     exit $1
 }
 
+script_dir=$(dirname $(readlink "$BASH_SOURCE"))
+
+# todo: finish figuring out fai / distro-setup
+# initial fstab / subvol setup.
+
 conf_only=false
 dry_run=false # mostly for testing
 
-temp=$(getopt -l help,long-opt hcnt "$@") || usage 1
+temp=$(getopt -l help hcnt: "$@") || usage 1
 eval set -- "$temp"
 while true; do
     case $1 in
@@ -30,9 +35,6 @@ read primary <<<"$@"
 
 ##### end command line parsing ########
 
-sed="sed -r --follow-symlinks"
-last_snaps=()
-
 target-section() {
     local root=$1
     local subvol=$2
@@ -51,24 +53,18 @@ rsync-dirs() {
     rsync $dry_run_arg -ahi --relative --delete "$path" "root@$host:/"
 }
 
-last-snap() {
-    vol=${1##*/}
-    cd /mnt/root
-    last_snap=$(
-        for f in $vol.20*; do
-            printf "%s %s\n" $(date -d $(sed -r  's/(.{4})(..)(.{5})(..)(.*)/\1-\2-\3:\4:\5/' <<<${f#$vol.}) +%s) $f
-        done | sort -r | head -n 1 | awk '{print $2}'
-             )
-    last_snaps+=($last_snap)
-}
 
 # note q is owned by root:1000
 # note p is owned 1000:1000 and chmod 700
 mountpoints=(/q)
-if mountpoint /p; then
+if awk '{print $2}' /etc/fstab | grep -xF /p &>/dev/null; then
     mountpoints+=(/p)
 fi
 
+# if our mountpoints are from stale snapshots,
+# it doesn't make sense to do a backup.
+check-subvol-stale ${mountpoints[@]} || exit 1
+
 if [[ ! $targets ]]; then
     case $HOSTNAME in
         tp|x2)
@@ -81,24 +77,13 @@ if [[ ! $targets ]]; then
 fi
 
 
+# todo: make bash shell prompt show something when
+# a subvol on current host is not fresh.
 # umount first to ensure we don't have any errors
 # todo: do some kill fuser stuff to make umount more reliable
-# todo: setup sync systemd timer on $primary, once per hour.
+# todo: run this on a systemd timer on $primary, once per hour.
 # todo: setup lock so that if this is already running, we exit out, so
 # that manual runs don't interfere with cronjobs.
-if [[ $primary ]] && ! $dry_run; then
-    for m in ${mountpoints[@]}; do
-        # note, this won't work for /i, due to path being /mnt/iroot
-        # todo: include /i for treetowl/frodo
-        btrfs property set -ts /mnt/root$m ro true
-        ssh root@$primary bash <<EOF
-set -ex
-umount $m
-[[ -e /mnt/root$m ]] || exit 0
-btrfs sub del /mnt/root$m
-EOF
-    done
-fi
 
 for tg in ${targets[@]}; do
     cat >/etc/btrbk.conf <<'EOF'
@@ -115,7 +100,11 @@ timestamp_format long-iso
 snapshot_create onchange
 # much less snapshots because I have less space on the
 # local filesystem.
-snapshot_preserve 2h 2d
+#snapshot_preserve 2h 2d
+# for now, keeping them equal for simplicity sake
+snapshot_preserve 48h 14d 8w 24m
+snapshot_preserve_min 6h
+snapshot_dir btrbk
 
 # so, total backups = ~89
 target_preserve 48h 14d 8w 24m
@@ -125,13 +114,13 @@ target_preserve_min 6h
 # btrbk -l debug -v dryrun
 EOF
 
-    remote_target="target send-receive ssh://${tg}/mnt/root"
+    remote_target="target send-receive ssh://${tg}/mnt/root/btrbk"
 
     if [[ $tg == frodo && $HOSTNAME == treetowl ]]; then
         target-section /mnt/iroot i
     fi
-    for m in ${mountpoints[@]}; do
-        target-section /mnt/root ${m##*/}
+    for d in ${mountpoints[@]}; do
+        target-section /mnt/root ${d##*/}
     done
 done
 
@@ -146,15 +135,14 @@ else
 fi
 
 # if we have /p, rsync to targets without /p
-if mountpoint /p; then
+if mountpoint /p >/dev/null; then
     for tg in ${targets[@]}; do
         case $tg in
             tp|li|lk)
-                # todo, test this
                 for x in /p/c/machine_specific/*.hosts; do
                     if grep -qxF $tg $x; then
                         dir=${x%.hosts}
-                        rsync-dirs ${dir##*/} $dir
+                        rsync-dirs $tg $dir
                     fi
                 done
                 ;;
@@ -162,38 +150,23 @@ if mountpoint /p; then
     done
 fi
 
-first_root=$(awk '$2 == "/mnt/root" {print $1}' /etc/mtab)
-
-# make $primary have the rw snapshot
-if [[ $primary ]] && ! $dry_run; then
-    fstab=()
-    for m in ${mountpoints[@]}; do
-        last-snap $m
-        fstab+=("$first_root  $m  btrfs  noatime,subvol=$last_snap  0 0")
-    done
-
-    printf "%s\n" "${fstab[@]}" | cedit /etc/fstab
-    for d in ${mountpoints[@]}; do
-        mount $d
-        btrfs sub del /mnt/root$d
-    done
-    ssh root@primary bash -s "${mountpoints[*]}" "${last_snaps[*]}" <<'EOF'
-set -xe
-mountpoints=($1)
-last_snaps=($2)
-first_root=$(awk '$2 == "/mnt/root" {print $1}' /etc/mtab)
-for ((i=0; i < ${#mountpoints[@]}; i++)); do
-  m=${mountpoints[i]}
-  vol=${m##*/}
-  fstab+=("$first_root $m  btrfs  noatime,subvol=$vol  0 0")
-  cd /mnt/root
-  btrfs sub snapshot ${last_snaps[i]} $vol
-  mount $m
-done
+if ! $dry_run; then
+    for tg in ${targets[@]}; do
+        scp $script_dir/{mount-latest-subvol,check-subvol-stale} \
+            root@tg:/usr/local/bin
+        ssh root@$tg bash <<'EOF'
+set -e
+chmod +x /usr/local/bin/{mount-latest-subvol,check-subvol-stale}
+mount-latest-subvol
 EOF
+    done
 fi
 
 
+# todo: move variable data we don't care about backing up
+# to /nocow and symlink it.
+
+
 # background on btrbk timezones. with short/long, timestamps use local time.
 # for long, if your local time moves backwards, by moving timezones or
 # for an hour when daylight savings changes it, you will temporarily get
@@ -208,3 +181,5 @@ fi
 # However, in the short term, there will be no inconsistencies.
 # I don't see any problem with shifting when the day starts for
 # retention, so I'm using long-iso.
+
+# note to create a long-iso timestamp: date +%Y%m%dT%H%M%S%z