diff --git a/qa/workunits/cephtool/test.sh b/qa/workunits/cephtool/test.sh
index 51e7ab4dbbe..4b24e69c874 100755
--- a/qa/workunits/cephtool/test.sh
+++ b/qa/workunits/cephtool/test.sh
@@ -439,6 +439,8 @@ ceph osd pool get rbd crush_ruleset | grep 'crush_ruleset: 0'
 
 ceph osd thrash 10
 
+
+
 set +e
 
 # expect error about missing 'pool' argument
@@ -460,4 +462,43 @@ ceph heap dump
 ceph heap stop_profiler
 ceph heap release
 
+
+# test osd bench limits
+# As we should not rely on defaults (as they may change over time),
+# lets inject some values and perform some simple tests
+# max iops: 10              # 100 IOPS
+# max throughput: 10485760  # 10MB/s
+# max block size: 2097152   # 2MB
+# duration: 10              # 10 seconds
+
+ceph tell osd.0 injectargs "\
+  --osd-bench-duration 10 \
+  --osd-bench-max-block-size 2097152 \
+  --osd-bench-large-size-max-throughput 10485760 \
+  --osd-bench-small-size-max-iops 10"
+
+# anything with a bs larger than 2097152  must fail
+expect_false ceph tell osd.0 bench 1 2097153
+# but using 'osd_bench_max_bs' must succeed
+ceph tell osd.0 bench 1 2097152
+
+# we assume 1MB as a large bs; anything lower is a small bs
+# for a 4096 bytes bs, for 10 seconds, we are limited by IOPS
+# max count: 409600
+
+# more than max count must not be allowed
+expect_false ceph tell osd.0 bench 409601 4096
+# but 409600 must be succeed
+ceph tell osd.0 bench 409600 4096
+
+# for a large bs, we are limited by throughput.
+# for a 2MB block size for 10 seconds, out max count is 50
+# max count: 50
+
+# more than max count must not be allowed
+expect_false ceph tell osd.0 bench 51 2097152
+# but 50 must succeed
+ceph tell osd.0 bench 50 2097152
+
+
 echo OK
diff --git a/src/common/config_opts.h b/src/common/config_opts.h
index 8bbd58671e0..560a975b35d 100644
--- a/src/common/config_opts.h
+++ b/src/common/config_opts.h
@@ -580,6 +580,11 @@ OPTION(osd_objectstore, OPT_STR, "filestore")  // ObjectStore backend type
 // Set to true for testing.  Users should NOT set this.
 OPTION(osd_debug_override_acting_compat, OPT_BOOL, false)
 
+OPTION(osd_bench_small_size_max_iops, OPT_U32, 100) // 100 IOPS
+OPTION(osd_bench_large_size_max_throughput, OPT_U64, 100 << 20) // 100 MB/s
+OPTION(osd_bench_max_block_size, OPT_U64, 64 << 20) // cap the block size at 64MB
+OPTION(osd_bench_duration, OPT_U32, 30) // duration of 'osd bench', capped at 30s to avoid triggering timeouts
+
 OPTION(filestore_debug_disable_sharded_check, OPT_BOOL, false)
 
 /// filestore wb throttle limits
diff --git a/src/osd/OSD.cc b/src/osd/OSD.cc
index 7bf1f5bcbdb..f229bc08503 100644
--- a/src/osd/OSD.cc
+++ b/src/osd/OSD.cc
@@ -4283,6 +4283,59 @@ void OSD::do_command(Connection *con, tid_t tid, vector<string>& cmd, bufferlist
     cmd_getval(cct, cmdmap, "count", count, (int64_t)1 << 30);
     cmd_getval(cct, cmdmap, "size", bsize, (int64_t)4 << 20);
 
+    uint32_t duration = g_conf->osd_bench_duration;
+
+    if (bsize > (int64_t) g_conf->osd_bench_max_block_size) {
+      // let us limit the block size because the next checks rely on it
+      // having a sane value.  If we allow any block size to be set things
+      // can still go sideways.
+      ss << "block 'size' values are capped at "
+         << prettybyte_t(g_conf->osd_bench_max_block_size) << ". If you wish to use"
+         << " a higher value, please adjust 'osd_bench_max_block_size'";
+      r = -EINVAL;
+      goto out;
+    } else if (bsize < (int64_t) (1 << 20)) {
+      // entering the realm of small block sizes.
+      // limit the count to a sane value, assuming a configurable amount of
+      // IOPS and duration, so that the OSD doesn't get hung up on this,
+      // preventing timeouts from going off
+      int64_t max_count =
+        bsize * duration * g_conf->osd_bench_small_size_max_iops;
+      if (count > max_count) {
+        ss << "'count' values greater than " << max_count
+           << " for a block size of " << prettybyte_t(bsize) << ", assuming "
+           << g_conf->osd_bench_small_size_max_iops << " IOPS,"
+           << " for " << duration << " seconds,"
+           << " can cause ill effects on osd. "
+           << " Please adjust 'osd_bench_small_size_max_iops' with a higher"
+           << " value if you wish to use a higher 'count'.";
+        r = -EINVAL;
+        goto out;
+      }
+    } else {
+      // 1MB block sizes are big enough so that we get more stuff done.
+      // However, to avoid the osd from getting hung on this and having
+      // timers being triggered, we are going to limit the count assuming
+      // a configurable throughput and duration.
+      int64_t total_throughput =
+        g_conf->osd_bench_large_size_max_throughput * duration;
+      int64_t max_count = (int64_t) (total_throughput / bsize);
+      if (count > max_count) {
+        ss << "'count' values greater than " << max_count
+           << " for a block size of " << prettybyte_t(bsize) << ", assuming "
+           << prettybyte_t(g_conf->osd_bench_large_size_max_throughput) << "/s,"
+           << " for " << duration << " seconds,"
+           << " can cause ill effects on osd. "
+           << " Please adjust 'osd_bench_large_size_max_throughput'"
+           << " with a higher value if you wish to use a higher 'count'.";
+        r = -EINVAL;
+        goto out;
+      }
+    }
+
+    dout(1) << " bench count " << count
+            << " bsize " << prettybyte_t(bsize) << dendl;
+
     bufferlist bl;
     bufferptr bp(bsize);
     bp.zero();