nbdkit/0010-cow-Improve-documentation-of-cow-on-cache-option.patch
Richard W.M. Jones b4d42fa29b More efficient cache and cow filters.
Add nbdkit-cow-filter cow-on-read option.
Add nbdkit-cache-filter cache-on-read=/PATH.
Add nbdkit-cache-filter cache-min-block-size option.
Add nbdkit-delay-filter delay-open and delay-close options.
Reduce verbosity of debugging from virt-v2v.
Miscellaneous bugfixes
resolves: rhbz#1950632
2021-07-30 18:40:23 +01:00

38 lines
1.4 KiB
Diff

From ef0ee0166b0594b04c73376f84a729c2985ca064 Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Tue, 27 Jul 2021 23:10:24 +0100
Subject: [PATCH] cow: Improve documentation of cow-on-cache option
(cherry picked from commit 9731e80d58c3aed2514d249e7925c2053d6eb0e8)
---
filters/cow/nbdkit-cow-filter.pod | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/filters/cow/nbdkit-cow-filter.pod b/filters/cow/nbdkit-cow-filter.pod
index 64df3fbd..2a693ebe 100644
--- a/filters/cow/nbdkit-cow-filter.pod
+++ b/filters/cow/nbdkit-cow-filter.pod
@@ -54,12 +54,13 @@ serve the same data to each client.
=item B<cow-on-cache=true>
-Treat a client cache request as a shortcut for copying unmodified data
-from the plugin to the overlay, rather than the default of passing
-cache requests on to the plugin. This parameter defaults to false
-(which leaves the overlay as small as possible), but setting it can be
-useful for converting cache commands into a form of copy-on-read
-behavior, in addition to the filter's normal copy-on-write semantics.
+When the client issues a cache (prefetch) request, preemptively save
+the data from the plugin into the overlay.
+
+=item B<cow-on-cache=false>
+
+Do not save data from cache (prefetch) requests in the overlay. This
+leaves the overlay as small as possible. This is the default.
=back
--
2.31.1