1-install: generate a large file faster

Use seek option of dd to create the large file.

diff --git a/install/scripts/1-install b/install/scripts/1-install
index 0c62368..f5d5c62 100644 (file)
--- a/install/scripts/1-install
+++ b/install/scripts/1-install
@@ -285,6 +285,16 @@ check_data_img()
        losetup -d /dev/loop7
 }
 
+gen_img()
+{
+       if [ "$fs" = "vfat" ]; then
+               ( dd bs=1M count=$1 if=/dev/zero | pv -ns $1m | dd of=$2 ) 2>&1 \
+                       | progress_bar "Creating `basename $2`" "Expect to write $1 MB..."
+       else
+               dd if=/dev/zero bs=1 count=0 seek=$1M of=$2
+       fi
+}
+
 create_img()
 {
        bname=`basename $2`
@@ -298,8 +308,7 @@ create_img()
                "\nPlease input the size of the $bname in MB:" 8 63 $1 2> $tempfile
        size=`cat $tempfile`
        [ 0$size -le 0 ] && size=2048
-       ( dd bs=1M count=$size if=/dev/zero | pv -ns ${size}m | dd of=$2 ) 2>&1 \
-               | progress_bar "Creating $bname" "Expect to write $size MB..."
+       gen_img $size $2
 }
 
 create_data_img()