X-Git-Url: http://git.annexia.org/?p=libguestfs.git;a=blobdiff_plain;f=guestfs-actions.pod;h=2705c3b3f709bce2e0d956c8e512c79b8eb39537;hp=0b06470da0b3332bb5a40e0bfcb6484f2e3aa21d;hb=d1a1ab972bb22f4c38a21fcc73f81650aaa03b4e;hpb=bfdc03be234d6d95f18450846433bce4f97e184c

diff --git a/guestfs-actions.pod b/guestfs-actions.pod
index 0b06470..2705c3b 100644
--- a/guestfs-actions.pod
+++ b/guestfs-actions.pod
@@ -7,6 +7,11 @@ This function adds a virtual CD-ROM disk image to the guest.
 
 This is equivalent to the qemu parameter C<-cdrom filename>.
 
+Note that this call checks for the existence of C<filename>.  This
+stops you from specifying other types of drive which are supported
+by qemu such as C<nbd:> and C<http:> URLs.  To specify those, use
+the general C<guestfs_config> call instead.
+
 This function returns 0 on success or -1 on error.
 
 =head2 guestfs_add_drive
@@ -27,6 +32,35 @@ image).
 
 This is equivalent to the qemu parameter C<-drive file=filename>.
 
+Note that this call checks for the existence of C<filename>.  This
+stops you from specifying other types of drive which are supported
+by qemu such as C<nbd:> and C<http:> URLs.  To specify those, use
+the general C<guestfs_config> call instead.
+
+This function returns 0 on success or -1 on error.
+
+=head2 guestfs_add_drive_ro
+
+ int guestfs_add_drive_ro (guestfs_h *handle,
+		const char *filename);
+
+This adds a drive in snapshot mode, making it effectively
+read-only.
+
+Note that writes to the device are allowed, and will be seen for
+the duration of the guestfs handle, but they are written
+to a temporary file which is discarded as soon as the guestfs
+handle is closed.  We don't currently have any method to enable
+changes to be committed, although qemu can support this.
+
+This is equivalent to the qemu parameter
+C<-drive file=filename,snapshot=on>.
+
+Note that this call checks for the existence of C<filename>.  This
+stops you from specifying other types of drive which are supported
+by qemu such as C<nbd:> and C<http:> URLs.  To specify those, use
+the general C<guestfs_config> call instead.
+
 This function returns 0 on success or -1 on error.
 
 =head2 guestfs_aug_close