diff --git a/.gitignore b/.gitignore
index 3b2ad4e..83d8252 100644
--- a/.gitignore
+++ b/.gitignore
@@ -45,6 +45,7 @@ TAGS
 /tests/Makefile
 /utils/Makefile.in
 /utils/Makefile
+/utils/iscsi-discard
 /utils/iscsi-inq
 /utils/iscsi-ls
 /utils/iscsi-perf
diff --git a/utils/Makefile.am b/utils/Makefile.am
index 271f5d2..931731a 100644
--- a/utils/Makefile.am
+++ b/utils/Makefile.am
@@ -3,7 +3,7 @@ AM_CFLAGS = $(WARN_CFLAGS)
 AM_LDFLAGS = -no-undefined
 LIBS = ../lib/libiscsi.la
 
-bin_PROGRAMS = iscsi-inq iscsi-ls iscsi-swp iscsi-pr
+bin_PROGRAMS = iscsi-inq iscsi-ls iscsi-swp iscsi-pr iscsi-discard
 if !TARGET_OS_IS_WIN32
 bin_PROGRAMS += iscsi-perf iscsi-readcapacity16
 endif
diff --git a/utils/iscsi-discard.c b/utils/iscsi-discard.c
new file mode 100644
index 0000000..f01e4e6
--- /dev/null
+++ b/utils/iscsi-discard.c
@@ -0,0 +1,216 @@
+/* 
+   Copyright (C) 2023 by zhenwei pi <pizhenwei@bytedance.com>
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <inttypes.h>
+#include <string.h>
+#include <poll.h>
+#include <getopt.h>
+#include "iscsi.h"
+#include "scsi-lowlevel.h"
+
+const char *initiator = "iqn.2007-10.com.github:sahlberg:libiscsi:iscsi-discard";
+
+void print_help(void)
+{
+	fprintf(stderr, "Usage: iscsi_readcapacity16 [OPTION...] <iscsi-url>\n");
+	fprintf(stderr, "  -i, --initiator-name=iqn-name     Initiatorname to use\n");
+	fprintf(stderr, "  -o, --offset                      "
+			"Byte offset into the target from which to start discarding. "
+			"The provided value must be aligned to the target sector size. "
+			"The default value is zero.\n");
+	fprintf(stderr, "  -l, --length                      "
+			"The number of bytes to discard (counting from the starting point). "
+			"The provided value must be aligned to the target sector size. "
+			"If the specified value extends past the end of the device, "
+			"iscsi-discard will stop at the device size boundary. "
+			"The default value extends to the end of the device.\n");
+	fprintf(stderr, "  -z, --zeroout                     "
+			"Zero-fill rather than discard.\n");
+	fprintf(stderr, "  -d, --debug=integer               debug level (0=disabled)\n");
+	fprintf(stderr, "\n");
+	fprintf(stderr, "Help options:\n");
+	fprintf(stderr, "  -?, --help                        Show this help message\n");
+	fprintf(stderr, "\n");
+	fprintf(stderr, "iSCSI URL format : %s\n", ISCSI_URL_SYNTAX);
+	fprintf(stderr, "\n");
+	fprintf(stderr, "<host> is either of:\n");
+	fprintf(stderr, "  \"hostname\"       iscsi.example\n");
+	fprintf(stderr, "  \"ipv4-address\"   10.1.1.27\n");
+	fprintf(stderr, "  \"ipv6-address\"   [fce0::1]\n");
+
+	exit(0);
+}
+
+int main(int argc, char *argv[])
+{
+	struct iscsi_context *iscsi;
+	char *url = NULL;
+	struct iscsi_url *iscsi_url = NULL;
+	int debug = 0, zeroout = 0;
+	int option_index, c;
+	unsigned int block_length;
+	long long offset = 0, length = 0, capacity, lba, blocks;
+	struct scsi_task *task;
+	struct scsi_readcapacity16 *rc16;
+	int ret = EINVAL;
+
+	static struct option long_options[] = {
+		{"offset",         required_argument,    NULL,        'o'},
+		{"length",         required_argument,    NULL,        'l'},
+		{"zeroout",        no_argument,          NULL,        'z'},
+		{"debug",          required_argument,    NULL,        'd'},
+		{"help",           no_argument,          NULL,        'h'},
+		{"initiator-name", required_argument,    NULL,        'i'},
+		{0, 0, 0, 0}
+	};
+
+	while ((c = getopt_long(argc, argv, "o:l:zd:i:h?", long_options,
+					&option_index)) != -1) {
+		switch (c) {
+			case 'o':
+				offset = strtoll(optarg, NULL, 0);
+				break;
+			case 'l':
+				length = strtoll(optarg, NULL, 0);
+				break;
+			case 'z':
+				zeroout = 1;
+				break;
+			case 'd':
+				debug = strtol(optarg, NULL, 0);
+				break;
+			case 'i':
+				initiator = optarg;
+				break;
+			case 'h':
+			case '?':
+				print_help();
+				break;
+			default:
+				fprintf(stderr, "Unrecognized option '%c'\n\n", c);
+				print_help();
+				break;
+		}
+	}
+
+	iscsi = iscsi_create_context(initiator);
+	if (iscsi == NULL) {
+		fprintf(stderr, "Failed to create context\n");
+		exit(EINVAL);
+	}
+
+	if (debug > 0) {
+		iscsi_set_log_fn(iscsi, iscsi_log_to_stderr);
+		iscsi_set_log_level(iscsi, debug);
+	}
+
+	if (argv[optind] != NULL) {
+		url = strdup(argv[optind]);
+	}
+	if (url == NULL) {
+		fprintf(stderr, "You must specify the URL\n");
+		print_help();
+	}
+	iscsi_url = iscsi_parse_full_url(iscsi, url);
+
+	free(url);
+
+	if (iscsi_url == NULL) {
+		fprintf(stderr, "Failed to parse URL: %s\n", 
+				iscsi_get_error(iscsi));
+		exit(EINVAL);
+	}
+
+	iscsi_set_session_type(iscsi, ISCSI_SESSION_NORMAL);
+	iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE_CRC32C);
+
+	if (iscsi_full_connect_sync(iscsi, iscsi_url->portal, iscsi_url->lun) != 0) {
+		fprintf(stderr, "Login Failed. %s\n", iscsi_get_error(iscsi));
+		goto out;
+	}
+
+	task = iscsi_readcapacity16_sync(iscsi, iscsi_url->lun);
+	if (task == NULL || task->status != SCSI_STATUS_GOOD) {
+		fprintf(stderr,"Failed to send readcapacity command\n");
+		goto out;
+	}
+
+	rc16 = scsi_datain_unmarshall(task);
+	if (rc16 == NULL) {
+		fprintf(stderr,"Failed to unmarshall readcapacity16 data\n");
+		goto out;
+	}
+
+	block_length = rc16->block_length;
+	if (offset & (block_length - 1)) {
+		fprintf(stderr,"Unaligned offset of %u\n", block_length);
+		goto free_task;
+	}
+
+	capacity = block_length * (rc16->returned_lba + 1);
+	if (offset > capacity) {
+		fprintf(stderr,"Offset(%lld) exceeds capacity(%lld)\n", offset, capacity);
+		goto free_task;
+	}
+
+	if (!length || (offset + length > capacity)) {
+		length = block_length * (rc16->returned_lba + 1) - offset;
+	}
+
+	/* free readcapacity16 task */
+	scsi_free_scsi_task(task);
+
+	lba = offset / block_length;
+	blocks = length / block_length;
+	if (zeroout) {
+		void *zerobuf = calloc(block_length, 1);
+
+		assert(zerobuf);
+		task = iscsi_writesame16_sync(iscsi, iscsi_url->lun, lba, zerobuf,
+				block_length, blocks, 0, 0, 0, 0);
+		if (task == NULL || task->status != SCSI_STATUS_GOOD) {
+			fprintf(stderr,"Failed to execute writesame16 command\n");
+			goto out;
+		}
+	} else {
+		struct unmap_list list;
+
+		list.lba = lba;
+		list.num = blocks;
+		task = iscsi_unmap_sync(iscsi, iscsi_url->lun, 0, 0, &list, 1);
+		if (task == NULL || task->status != SCSI_STATUS_GOOD) {
+			fprintf(stderr,"Failed to execute unmap command\n");
+			goto out;
+		}
+	}
+
+	ret = 0;
+
+free_task:
+	scsi_free_scsi_task(task);
+
+out:
+	iscsi_destroy_url(iscsi_url);
+	iscsi_logout_sync(iscsi);
+	iscsi_destroy_context(iscsi);
+
+	return ret;
+}