--- a/src/test/objectstore/test_bdev.cc
+++ b/src/test/objectstore/test_bdev.cc
@@ -54,8 +54,8 @@
     BlockDevice::create(g_ceph_context, bdev.path, NULL, NULL,
       [](void* handle, void* aio) {}, NULL));
   bufferlist bl;
-  // writing a bit less than 4GB
-  for (auto i = 0; i < 4000; i++) {
+  // writing a bit less than 1GB
+  for (auto i = 0; i < 1000; i++) {
     string s(1048576, 'a' + (i % 28));
     bl.append(s);
   }
--- a/src/test/objectstore/test_bluefs.cc
+++ b/src/test/objectstore/test_bluefs.cc
@@ -237,7 +237,7 @@
 }
 
 TEST(BlueFS, very_large_write) {
-  // we'll write a ~5G file, so allocate more than that for the whole fs
+  // we'll write a ~1G file, so allocate more than that for the whole fs
   uint64_t size = 1048576 * 1024 * 6ull;
   TempBdev bdev{size};
   BlueFS fs(g_ceph_context);
@@ -260,12 +260,12 @@
     BlueFS::FileWriter *h;
     ASSERT_EQ(0, fs.mkdir("dir"));
     ASSERT_EQ(0, fs.open_for_write("dir", "bigfile", &h, false));
-    for (unsigned i = 0; i < 3*1024*1048576ull / sizeof(buf); ++i) {
+    for (unsigned i = 0; i < 1*1024*1048576ull / sizeof(buf); ++i) {
       h->append(buf, sizeof(buf));
       total_written += sizeof(buf);
     }
     fs.fsync(h);
-    for (unsigned i = 0; i < 2*1024*1048576ull / sizeof(buf); ++i) {
+    for (unsigned i = 0; i < 1*1024*1048576ull / sizeof(buf); ++i) {
       h->append(buf, sizeof(buf));
       total_written += sizeof(buf);
     }
@@ -278,7 +278,7 @@
     bufferlist bl;
     BlueFS::FileReaderBuffer readbuf(10485760);
     ASSERT_EQ(h->file->fnode.size, total_written);
-    for (unsigned i = 0; i < 3*1024*1048576ull / sizeof(buf); ++i) {
+    for (unsigned i = 0; i < 1*1024*1048576ull / sizeof(buf); ++i) {
       bl.clear();
       fs.read(h, &readbuf, i * sizeof(buf), sizeof(buf), &bl, NULL);
       int r = memcmp(buf, bl.c_str(), sizeof(buf));
@@ -288,7 +288,7 @@
       }
       ASSERT_EQ(0, r);
     }
-    for (unsigned i = 0; i < 2*1024*1048576ull / sizeof(buf); ++i) {
+    for (unsigned i = 0; i < 1*1024*1048576ull / sizeof(buf); ++i) {
       bl.clear();
       fs.read(h, &readbuf, i * sizeof(buf), sizeof(buf), &bl, NULL);
       int r = memcmp(buf, bl.c_str(), sizeof(buf));
@@ -313,7 +313,7 @@
 }
 
 TEST(BlueFS, very_large_write2) {
-  // we'll write a ~5G file, so allocate more than that for the whole fs
+  // we'll write a ~1G file, so allocate more than that for the whole fs
   uint64_t size_full = 1048576 * 1024 * 6ull;
   uint64_t size = 1048576 * 1024 * 5ull;
   TempBdev bdev{ size_full };