From b0b5fdc69f6ee831f325760f95a164627b499f77 Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Wed, 18 Apr 2012 10:50:32 +0100
Subject: sparsify: Add a note about sparsify on tmpfs.

---
 sparsify/virt-sparsify.pod | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/sparsify/virt-sparsify.pod b/sparsify/virt-sparsify.pod
index 275faf5a..14f7eecb 100644
--- a/sparsify/virt-sparsify.pod
+++ b/sparsify/virt-sparsify.pod
@@ -271,6 +271,14 @@ to point to another directory that has enough space.
 
 This defaults to C</tmp>.
 
+Note that if C<$TMPDIR> is a tmpfs (eg. if C</tmp> is on tmpfs, or if
+you use C<TMPDIR=/dev/shm>), tmpfs defaults to a maximum size of
+I<half> of physical RAM.  If virt-sparsify exceeds this, it will hang.
+The solution is either to use a real disk, or to increase the maximum
+size of the tmpfs mountpoint, eg:
+
+ mount -o remount,size=10G /tmp
+
 =back
 
 For other environment variables, see L<guestfs(3)/ENVIRONMENT VARIABLES>.
-- 
cgit