diff --git a/doc/047_tuning_backup_parameters.rst b/doc/047_tuning_backup_parameters.rst
index 78001bee6..dff992f1e 100644
--- a/doc/047_tuning_backup_parameters.rst
+++ b/doc/047_tuning_backup_parameters.rst
@@ -8,6 +8,7 @@
   - for subsections
   ^ for subsubsections
   " for paragraphs
+
 ########################
 Tuning Backup Parameters
 ########################
@@ -48,3 +49,22 @@ which will compress very fast), ``max`` (which will trade backup speed and CPU u
 slightly better compression), or ``off`` (which disables compression). Each setting is
 only applied for the single run of restic. The option can also be set via the environment
 variable ``RESTIC_COMPRESSION``.
+
+
+Pack Size
+=========
+
+In certain instances, such as very large repositories, it is desired to have larger pack
+sizes to reduce the number of files in the repository.  Notable examples are OpenStack
+Swift and some Google Drive Team accounts, where there are hard limits on the total
+number of files.  This can be achieved by either using the ``--min-packsize`` flag
+or defining the ``$RESTIC_MIN_PACKSIZE`` environment variable.  Restic currently defaults
+to a 16MB minimum pack size.
+
+The side effect of increasing the pack size is increased client memory usage.  A bit of
+tuning may be required to strike a balance between memory usage and number of pack files.
+
+Restic uses the majority of it's memory according to the pack size, multiplied by the number
+of parallel writers. For example, if you have 4 parallel writers (restic creates one per
+available CPU), With a minimum pack size of 64 (Megabytes), you'll get a *minimum* of 256MB
+of memory usage.
diff --git a/doc/manual_rest.rst b/doc/manual_rest.rst
index 040c091fa..ba9ab8990 100644
--- a/doc/manual_rest.rst
+++ b/doc/manual_rest.rst
@@ -56,6 +56,7 @@ Usage help is available:
           --key-hint key               key ID of key to try decrypting first (default: $RESTIC_KEY_HINT)
           --limit-download int         limits downloads to a maximum rate in KiB/s. (default: unlimited)
           --limit-upload int           limits uploads to a maximum rate in KiB/s. (default: unlimited)
+          --min-packsize uint          set min pack size in MiB. (default: $RESTIC_MIN_PACKSIZE or 16)
           --no-cache                   do not use a local cache
           --no-lock                    do not lock the repository, this allows some operations on read-only repositories
       -o, --option key=value           set extended option (key=value, can be specified multiple times)
@@ -128,6 +129,7 @@ command:
           --key-hint key               key ID of key to try decrypting first (default: $RESTIC_KEY_HINT)
           --limit-download int         limits downloads to a maximum rate in KiB/s. (default: unlimited)
           --limit-upload int           limits uploads to a maximum rate in KiB/s. (default: unlimited)
+          --min-packsize uint          set min pack size in MiB. (default: $RESTIC_MIN_PACKSIZE or 16)
           --no-cache                   do not use a local cache
           --no-lock                    do not lock the repository, this allows some operations on read-only repositories
       -o, --option key=value           set extended option (key=value, can be specified multiple times)
@@ -440,3 +442,4 @@ time it is used, so by looking at the timestamps of the sub directories of the
 cache directory it can decide which sub directories are old and probably not
 needed any more. You can either remove these directories manually, or run a
 restic command with the ``--cleanup-cache`` flag.
+