Set nice value and detach from cron

[backups/.git] / scripts / burn-imgs.sh

diff --git a/scripts/burn-imgs.sh b/scripts/burn-imgs.sh
index 81cbee0b1e554b788efcadd96431ac47638e77c3..b4d71bf807219ff3189e41894780f1a971d6a9d7 100755 (executable)
--- a/scripts/burn-imgs.sh
+++ b/scripts/burn-imgs.sh
@@ -1,15 +1,19 @@
 #!/bin/sh
 
-PATH=$(dirname $0):/bin:/usr/bin
+export PATH=$(dirname $0):/bin:/usr/bin:/sbin
 
+cronstopstart="/etc/init.d/cron"
 . config.sh
 
 # If the noburn file is there then don't burn.
 [ -f "$noburnfile" ] && exit 0
-touch $noburnfile
 
 # Discover disk images by looking for .img.md5sum files in $imagedir
-imgmd5=$(ls $imagedir/*.img.md5sum | head -n 1)
+imgmd5=$(ls $imagedir/*.img.md5sum 2>/dev/null | head -n 1)
+
+# If we didn't find an non-empty file then exit gracefully
+[ -z "$imgmd5" ] && exit 0
+[ -s "$imgmd5" ] || exit 0
 
 echo MD5 file: $imgmd5
 
@@ -17,19 +21,21 @@ logfile=$(tempfile)
 
 echo Logfile: $logfile
 
-# If we didn't find an non-empty file then exit gracefully
-[ -z "$imgmd5" ] && exit 0
-[ -s "$imgmd5" ] || exit 0
-
 # Get the name of the disk image by stripping off the tailing '.md5sum'
 img=${imgmd5%.md5sum}
 
 echo Image: $img
 
+touch $noburnfile
+
 # A little paranoia.  Make sure the disk image file is there.
 [ -z "$img" ] && exit 1
 [ -s "$img" ] || exit 1
 
+# To avoid buffer underruns I'm going to stop cron and renice myself
+$cronstopstart stop
+renice -10 $$
+
 # Burn the image to a disk.
 cdrecord-wrapper.sh -dao dev=$sdev $img > $logfile 2>&1
 
@@ -38,6 +44,10 @@ if [ "0" != "$?" ]; then
   exit 1
 fi
 
+# We don't need to be high-priority anymore.
+renice 0 $$
+$cronstopstart start
+
 # Now verify the disk by running md5sum on the entire contents of the disk
 md5sum=$(tempfile)
 echo Md5sum: $md5sum