X-Git-Url: http://git.annexia.org/?p=libguestfs.git;a=blobdiff_plain;f=guestfish-actions.pod;h=9b07c402cb16a5dbe1376f4ee17746567959f169;hp=ee8e82477bc4bb2385a23b4ea0ea03eb37c686c3;hb=d1a1ab972bb22f4c38a21fcc73f81650aaa03b4e;hpb=1fc41b39dac877ccec1284da8bb14baa4df368b8

diff --git a/guestfish-actions.pod b/guestfish-actions.pod
index ee8e824..9b07c40 100644
--- a/guestfish-actions.pod
+++ b/guestfish-actions.pod
@@ -6,6 +6,11 @@ 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<config> call instead.
+
 =head2 add-drive | add
 
  add-drive filename
@@ -23,6 +28,32 @@ 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<config> call instead.
+
+=head2 add-drive-ro | add-ro
+
+ add-drive-ro 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<config> call instead.
+
 =head2 aug-close
 
  aug-close
@@ -484,6 +515,17 @@ Setting C<whattodrop> to 3 should drop everything.
 This automatically calls L<sync(2)> before the operation,
 so that the maximum guest memory is freed.
 
+=head2 e2fsck-f
+
+ e2fsck-f device
+
+This runs C<e2fsck -p -f device>, ie. runs the ext2/ext3
+filesystem checker on C<device>, noninteractively (C<-p>),
+even if the filesystem appears to be clean (C<-f>).
+
+This command is only needed because of C<resize2fs>
+(q.v.).  Normally you should use C<fsck>.
+
 =head2 equal
 
  equal file1 file2
@@ -989,6 +1031,12 @@ function which has a more complex interface.
 This resizes an ext2 or ext3 filesystem to match the size of
 the underlying device.
 
+I<Note:> It is sometimes required that you run C<e2fsck-f>
+on the C<device> before calling this command.  For unknown reasons
+C<resize2fs> sometimes gives an error about this and sometimes not.
+In any case, it is always safe to call C<e2fsck-f> before
+calling this function.
+
 =head2 rm
 
  rm path