diff --git a/plugins/disk/raid b/plugins/disk/raid
index 440fddce..120bc366 100755
--- a/plugins/disk/raid
+++ b/plugins/disk/raid
@@ -12,11 +12,11 @@
 
 if ($ARGV[0] and $ARGV[0] eq "autoconf") {
     if (-r "/proc/mdstat" and `grep md /proc/mdstat`) {
-	print "yes\n";
-	exit 0;
+        print "yes\n";
+        exit 0;
     } else {
-	print "no RAID devices\n";
-	exit 1;
+        print "no RAID devices\n";
+        exit 1;
     }
 }
 
@@ -29,52 +29,105 @@ if ( $ARGV[0] and $ARGV[0] eq "config" ) {
     print "graph_scale  no\n";
 }
 
-{
-    local( $/, *MDSTAT ) ;
-    open (MDSTAT, "/proc/mdstat") or exit 1;
-    #open (MDSTAT, "/etc/munin/plugins/sample.failed") or exit 1;
-    my $text = <MDSTAT>;
-    close MDSTAT;
+open(my $mdstat, "/proc/mdstat");
+my(@text) = <$mdstat>;
+# contents of <$mdstat> may be changed at next reading, so fetch the contents at a time
+close($mdstat);
 
-    # Should look like "active raid1 sda1[0] sdc1[2] sdb1[1]"
-    # Interestingly, swap is presented as "active (auto-read-only)"
-    while ($text =~ /(md\d+)\s+:\s+active\s+(\(auto-read-only\)\s+|)(\w+)\s+(.*)\n.*\[(\d+)\/(\d+)]\s+\[(\w+)]\n(.*(check|resync)\s=\s+(\d+\.\d+)%|.*\n)/ ) {
-        my($dev,$dummy,$type,$members,$nmem,$nact,$status,$dummy2,$dummy3,$proc) = ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10);
-#       print "$text\nitem: $dev $type ($members) status=$status $proc\n";
-	if ( $ARGV[0] and $ARGV[0] eq "config" ) {
-	    print "$dev.label $dev\n";
-	    print "$dev.info $type $members\n";
-	    # 100: means less than 100
-	    # Because of an unfound bug, sometimes reported as 99.XX even when OS reports 100.
-	    print "$dev.critical 98:\n";	
-	    print $dev, "_rebuild.label $dev rebuilt\n";
-	    print $dev, "_rebuild.info $type\n";
-	    # Because of an unfound bug, sometimes reported as 99.XX even when OS reports 100.
-	    print $dev, "_rebuild.critical 98:\n";	
-            print $dev, "_check.label $dev check/resync \n";
-            print $dev, "_check.info $type\n";
-	} else {
-	    my $pct = 100 * $nact / $nmem;
-	    my $rpct = 100;
-	    if ( $pct < 100 ) {
-		my @output = `/sbin/mdadm -D /dev/$dev | grep Rebuild`;
-                if( $output[0] and $output[0] =~ /([0-9]+)% complete/ ) {
-			$rpct = $1;
-		} else {
-			$rpct = 0;
-		}
-	    }
-            if ( $proc ) {
-                $cpct = $proc;
-            } else {
+my($devinfo_re, $devstat_re, $action_re) = (
+    '(md\d+)\s+:\s+active\s+(\(read-only\)\s+|\(auto-read-only\)\s+|)(\w+)\s+(.*)',
+    '.*\[(\d+)\/(\d+)]\s+\[(\w+)]',
+    '.*(reshape|check|resync|recovery)\s*=\s*(\d+\.\d+%|\w+)(.*finish=(.*min))?',
+);
+# Interestingly, swap is presented as "active (auto-read-only)"
+# and mdadm has '--readonly' option to make the array 'active (read-only)'
+
+my($dev, $ro, $type, $members, $nmem, $nact, $status, $action, $proc, $minute);
+while (@text) {
+    my $line = shift @text;
+    if ($line =~ /$devinfo_re/) {
+        # first line should like "active raid1 sda1[0] sdc1[2] sdb1[1]"
+        $dev = $1;
+        $ro = $2 || '';
+        $type = $3;
+        $members = $4;
+        
+        $line = shift @text;
+        if ($line =~ /$devstat_re/) {
+            # second line should like "123456 blocks super 1.2 [2/2] [UU]"
+            $nmem = $1;
+            $nact = $2;
+            $status = $3;
+        }
+        else {
+            # sencond line did not exist on /proc/mdstat
+            next;
+        }
+        
+        $line = shift @text;
+        if ($line =~ /$action_re/) {
+            # third line should like " [==>..................]  check = 10.0% (12345/123456) finish=123min speed=12345/sec"
+            # this line will appear only when the array is in action
+            $action = $1;
+            my $percent = $2;
+            $minute = $4 || '';
+            if ($percent =~ /(\d+\.\d+)%/) {
+                $proc = $1;
+            }
+            else {
+                # 'resync=DELAYED' or 'resync=PENDING'
+                $action .= " ($percent)";
+                $proc = -1;
+            }
+        }
+        else {
+            # array is not in action
+            $action = 'idle';
+            $minute = '';
+            unshift(@text, $line);
+        }
+    }
+    else {
+        # skip until first line is found
+        next;
+    }
+
+    if ( $ARGV[0] and $ARGV[0] eq "config" ) {
+        print "$dev.label $dev\n";
+        print "$dev.info $type $ro$members\n";
+        # 100: means less than 100
+        # Because of an unfound bug, sometimes reported as 99.XX even when OS reports 100.
+        print "$dev.critical 98:\n";
+        print $dev, "_rebuild.label $dev reshape/recovery\n";
+        print $dev, "_rebuild.info $action $minute\n";
+        # Because of an unfound bug, sometimes reported as 99.XX even when OS reports 100.
+        print $dev, "_rebuild.critical 98:\n";
+        print $dev, "_check.label $dev check/resync \n";
+        print $dev, "_check.info $action $minute\n";
+    } else {
+        my $pct = 100 * $nact / $nmem;
+        my $rpct = 100;
+        my $cpct = 100;
+        if ($action =~ /reshape|recovery/) {
+            $rpct = $proc;
+            $cpct = 0;  # check/resync is not done
+        }
+        elsif ($action =~ /check|resync/) {
+            if ($proc < 0) {
+                # array is on DELAYED or PENDING, further info is unknown
+                $rpct = 0;
                 $cpct = 0;
             }
-	    print "$dev.value $pct\n";
-	    print $dev, "_rebuild.value $rpct\n";
-            print $dev, "_check.value $cpct\n";	    
-	}
-	$text = $';
-    } 
+            else {
+                # reshape/recovery was done, $rpct => 100
+                $cpct = $proc;
+            }
+        }
+
+        print "$dev.value $pct\n";
+        print $dev, "_rebuild.value $rpct\n";
+        print $dev, "_check.value $cpct\n";
+    }
 }
 
 exit 0;