From 2d0f32547efdc040cd047668e9c3fb18b3adf046 Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sesse@samfundet.no>
Date: Sat, 4 Oct 2014 23:22:50 +0200
Subject: [PATCH] Use pigz if it is available, for less CPU-bound operation.

---
 backup.sh | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/backup.sh b/backup.sh
index 652b463..a6ebade 100755
--- a/backup.sh
+++ b/backup.sh
@@ -89,17 +89,17 @@ backup()
  exf=`ssh root@$computer "ls ~/.backup/exclude"`
 
  # We try to run tar on the remote computer
- #    z gzip it
  #    c create archive
  #    C change to directory first
  #    . where to start taring (see C)
  #    $lastcmd only files newer than this
  #    --one-file-system don't traverse file systems
+ #    --use-compress-program compress it using gzip or pigz
  #    --exclude-from file to get exclusion pattern from
  #    Pipe the stuff over ssh to ourselves, run pee to cat the contents to a
  #    file and build a file list, respectivly.  
  TARFILE=$DATE.tmp
- TARCMD="ssh root@$computer \"nice -n 19 ionice -c3 tar --one-file-system -zcf - -C $filesystem . $lastcmd \
+ TARCMD="ssh root@$computer \"nice -n 19 ionice -c3 tar --one-file-system --use-compress-program $compressor -cf - -C $filesystem . $lastcmd \
 	--exclude-from=$exf\" | pee \"cat > $TARFILE\" \"tar tzvf -\""
  echo `date`" $computer: Running $TARCMD" >&2
  eval $TARCMD > $DATE.idx
@@ -156,6 +156,14 @@ backup()
   # We don't want to return 0
   die
  fi
+
+ # Check if pigz is available
+ if ssh -n root@$computer "pigz -V 2>/dev/null"; then
+   compressor=pigz
+ else
+   echo `date`" $computer: pigz missing; falling back to gzip."
+   compressor=gzip
+ fi
  
  filesystems=""
 
-- 
2.39.2