diff --git a/sbin/hammer/hammer_util.h b/sbin/hammer/hammer_util.h
index b2972e0..8b10775 100644
--- a/sbin/hammer/hammer_util.h
+++ b/sbin/hammer/hammer_util.h
@@ -80,6 +80,7 @@ struct volume_info {
 	char			*name;
 	int			fd;
 	off_t			size;
+	off_t			device_offset;
 	const char		*type;
 
 	struct hammer_volume_ondisk *ondisk;
diff --git a/sbin/newfs_hammer/newfs_hammer.8 b/sbin/newfs_hammer/newfs_hammer.8
index 4cc049d..1789426 100644
--- a/sbin/newfs_hammer/newfs_hammer.8
+++ b/sbin/newfs_hammer/newfs_hammer.8
@@ -40,7 +40,7 @@
 .Sh SYNOPSIS
 .Nm
 .Fl L Ar label
-.Op Fl f
+.Op Fl fE
 .Op Fl b Ar bootsize
 .Op Fl m Ar savesize
 .Op Fl u Ar undosize
@@ -119,6 +119,10 @@ This is needed for the creation of a
 file system less than 10GB size or
 with less than 500MB UNDO/REDO FIFO.
 This should not be used under normal circumstances.
+.It Fl E
+Use TRIM to erase the device's data before creating the file system. The
+underlying device must have the Trim sysctl enabled. Only devices that support
+TRIM will have such a sysctl option (kern.cam.da.X.trim_enabled).
 .It Fl m Ar savesize
 Specify a fixed area which
 .Nm HAMMER
diff --git a/sbin/newfs_hammer/newfs_hammer.c b/sbin/newfs_hammer/newfs_hammer.c
index 19146b3..c5492de 100644
--- a/sbin/newfs_hammer/newfs_hammer.c
+++ b/sbin/newfs_hammer/newfs_hammer.c
@@ -38,6 +38,7 @@
 
 static int64_t getsize(const char *str, int64_t minval, int64_t maxval, int pw);
 static const char *sizetostr(off_t size);
+static void trim_volume(struct volume_info *vol);
 static void check_volume(struct volume_info *vol);
 static void format_volume(struct volume_info *vol, int nvols,const char *label,
 			off_t total_size);
@@ -47,6 +48,7 @@ static void usage(void);
 
 static int ForceOpt = 0;
 static int HammerVersion = -1;
+static int Eflag = 0;
 
 #define GIG	(1024LL*1024*1024)
 
@@ -82,11 +84,14 @@ main(int ac, char **av)
 	/*
 	 * Parse arguments
 	 */
-	while ((ch = getopt(ac, av, "fL:b:m:u:V:")) != -1) {
+	while ((ch = getopt(ac, av, "fEL:b:m:u:V:")) != -1) {
 		switch(ch) {
 		case 'f':
 			ForceOpt = 1;
 			break;
+		case 'E':
+			Eflag = 1;
+			break;
 		case 'L':
 			label = optarg;
 			break;
@@ -189,6 +194,29 @@ main(int ac, char **av)
 		 * its remaining fields.
 		 */
 		check_volume(vol);
+		if (Eflag) {
+			char sysctl_name[64];
+			int trim_enabled = 0;
+			size_t olen = sizeof(trim_enabled);
+			char *dev_name = strdup(vol->name);
+			dev_name = strtok(dev_name + strlen("/dev/da"),"s");
+
+			sprintf(sysctl_name, "kern.cam.da.%s.trim_enabled", dev_name);
+			errno=0;
+			sysctlbyname(sysctl_name, &trim_enabled, &olen, NULL, 0);
+			if(errno == ENOENT) {
+				printf("Device:%s (%s) does not support the TRIM command\n",
+				       vol->name,sysctl_name);
+				usage();
+			}
+			if(!trim_enabled) {
+				printf("Erase device option selected, but sysctl (%s) "
+				       "is not enabled\n",sysctl_name);
+				usage();
+
+			}
+			trim_volume(vol);
+		}
 		total += vol->size;
 	}
 
@@ -273,7 +301,7 @@ void
 usage(void)
 {
 	fprintf(stderr,
-		"usage: newfs_hammer -L label [-f] [-b bootsize] [-m savesize] [-u undosize]\n"
+		"usage: newfs_hammer -L label [-fE] [-b bootsize] [-m savesize] [-u undosize]\n"
 		"                    [-V version] special ...\n"
 	);
 	exit(1);
@@ -392,6 +420,25 @@ nowtime(void)
 }
 
 /*
+ * TRIM the volume, but only if the backing store is a DEVICE
+ */
+static
+void
+trim_volume(struct volume_info *vol)
+{
+	if (strncmp(vol->type, "DEVICE", sizeof(vol->type)) == 0) {
+		off_t ioarg[2];
+		
+		/* 1MB offset to prevent destroying disk-reserved area */
+		ioarg[0] = vol->device_offset;
+		ioarg[1] = vol->size;
+		printf("Trimming Device:%s, sectors (%llu -%llu)\n",vol->name,
+		     (unsigned long long)ioarg[0]/512,
+		     (unsigned long long)ioarg[1]/512);
+		ioctl(vol->fd, IOCTLTRIM, ioarg);
+	}
+}
+/*
  * Check basic volume characteristics.  HAMMER filesystems use a minimum
  * of a 16KB filesystem buffer size.
  */
@@ -416,6 +463,10 @@ check_volume(struct volume_info *vol)
 			err(1, "Unable to stat %s", vol->name);
 		vol->size = st.st_size;
 		vol->type = "REGFILE";
+
+		if (Eflag)
+			errx(1,"Cannot TRIM regular file %s\n", vol->name);
+
 	} else {
 		/*
 		 * When formatting a block device as a HAMMER volume the
@@ -433,6 +484,7 @@ check_volume(struct volume_info *vol)
 		}
 
 		vol->size = pinfo.media_size;
+		vol->device_offset = pinfo.media_offset;
 		vol->type = "DEVICE";
 	}
 	printf("Volume %d %s %-15s size %s\n",
diff --git a/sbin/newfs_hammer/newfs_hammer.h b/sbin/newfs_hammer/newfs_hammer.h
index 271e4fd..c134bf3 100644
--- a/sbin/newfs_hammer/newfs_hammer.h
+++ b/sbin/newfs_hammer/newfs_hammer.h
@@ -40,6 +40,7 @@
 #include <sys/stat.h>
 #include <sys/time.h>
 #include <sys/sysctl.h>
+#include <sys/ioctl_compat.h>
 
 #include <stdio.h>
 #include <stdlib.h>