Generated code for 'add_drive_ro' call.

[libguestfs.git] / perl / lib / Sys / Guestfs.pm

diff --git a/perl/lib/Sys/Guestfs.pm b/perl/lib/Sys/Guestfs.pm
index e7f8924..f8e6b77 100644 (file)
--- a/perl/lib/Sys/Guestfs.pm
+++ b/perl/lib/Sys/Guestfs.pm
@@ -97,6 +97,11 @@ 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<$h-E<gt>config> call instead.
+
 =item $h->add_drive ($filename);
 
 This function adds a virtual machine disk image C<filename> to the
@@ -112,6 +117,30 @@ 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<$h-E<gt>config> call instead.
+
+=item $h->add_drive_ro ($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<$h-E<gt>config> call instead.
+
 =item $h->aug_close ();
 
 Close the current Augeas handle and free up any resources
@@ -499,6 +528,15 @@ 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.
 
+=item $h->e2fsck_f ($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<$h-E<gt>resize2fs>
+(q.v.).  Normally you should use C<$h-E<gt>fsck>.
+
 =item $h->end_busy ();
 
 This sets the state to C<READY>, or if in C<CONFIG> then it leaves the
@@ -910,6 +948,12 @@ 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<$h-E<gt>e2fsck_f>
+on the C<device> before calling this command.  For unknown reasons
+C<resize2fs> sometimes gives an error about this and sometimes not.
+In any case, it is always safe to call C<$h-E<gt>e2fsck_f> before
+calling this function.
+
 =item $h->rm ($path);
 
 Remove the single file C<path>.