[Docs] Clarify Storage mounting details (skypilot-org#1365)

* fix incorrect statements

* fix incorrect statements

* fix incorrect statements

Author: romilbhardwaj

docs/source/reference/storage.rst

@@ -62,9 +62,8 @@ When specifying a storage object, you can specify either of two modes:
     In effect, files are streamed from the backing source bucket as and when
     they are accessed by applications. This mode also allows applications to
     write to the mount path. All writes are replicated to remote bucket (and
-    any other VMs mounting the same bucket). Please note that this mode
-    uses a close-to-open consistency model, which means a file write is
-    committed to the backing store only after :code:`close()` is called on it.
+    any other VMs mounting the same bucket).
+
 
 - :code:`mode: COPY`
     This mode pre-fetches your files from remote storage and caches them on the
@@ -176,6 +175,17 @@ and storage mounting:
     For mounts not using SkyPilot Storage (e.g., those using rsync) the symbolic links are directly copied, not their target data.
     The targets must be separately mounted or else the symlinks may break.
 
+.. note::
+    :code:`MOUNT` mode employs a close-to-open consistency model. This means calling
+    :code:`close()` on a file will upload the entire file to the backing object store.
+    Any subsequent reads, either using SkyPilot Storage or external utilities (such as
+    aws/gsutil cli) will see the latest data.
+
+.. note::
+    :code:`MOUNT` mode does not support the full POSIX interface and some file
+    operations may fail. Most notably, random writes and append operations are
+    not supported.
+
 .. note::
     Storage only supports uploading directories (i.e., :code:`source` cannot be a file).
     To upload a single file to a bucket, please put in a directory and specify the directory as the source.

examples/perf/results.md

@@ -41,8 +41,8 @@ We copy a 1 GB file from S3 to EBS using `aws s3 cp` command.
 * SkyPilot Storage offers higher **read** performance than EBS because it can directly
   stream files from S3 to memory.
 * SkyPilot Storage **write** performance is significantly higher than EBS because it
-  writes to memory and then asynchronously uploads to S3. SkyPilot Storage offers 
-  only eventual consistency, so a write operation to SkyPilot Storage may not reflect 
-  immediately on the S3 storage.
+  writes directly to S3 over network instead of disk.
+* SkyPilot Storage offers close-to-open consistency, so it is guaranteed that when a file is closed, 
+  subsequent opens will see the latest changes. 
 * These benchmarks are run on single large files. The performance of SkyPilot Storage
   degrades when using many small files.