X-Git-Url: http://git.annexia.org/?p=libguestfs.git;a=blobdiff_plain;f=src%2Fguestfs.pod;h=84eec6359caefec1c4287b06d77e25a97112213c;hp=30759602f45cfe3aeb6351ad60182a2e4b78b4c8;hb=c0baa7bdb2b404e8c808700984b3fc1a699d8dd7;hpb=8980c01b46eafcf4b5dc127e4696c2cbe1bff09f diff --git a/src/guestfs.pod b/src/guestfs.pod index 3075960..84eec63 100644 --- a/src/guestfs.pod +++ b/src/guestfs.pod @@ -36,8 +36,9 @@ LVs, what filesystem is in each LV, etc.). It can also run commands in the context of the guest. Also you can access filesystems over FTP. Libguestfs is a library that can be linked with C and C++ management -programs (or management programs written in OCaml, Perl, Python, Ruby, Java -or Haskell). You can also use it from shell scripts or the command line. +programs (or management programs written in OCaml, Perl, Python, Ruby, +Java, Haskell or C#). You can also use it from shell scripts or the +command line. You don't need to be root to use libguestfs, although obviously you do need enough permissions to access the disk images. @@ -480,11 +481,16 @@ You can use the I header file from C++ programs. The C++ API is identical to the C API. C++ classes and exceptions are not implemented. +=item B + +The C# bindings are highly experimental. Please read the warnings +at the top of C. + =item B -This is the only language binding that is incomplete. Only calls -which return simple integers have been bound in Haskell, and we are -looking for help to complete this binding. +This is the only language binding that working but incomplete. Only +calls which return simple integers have been bound in Haskell, and we +are looking for help to complete this binding. =item B @@ -518,6 +524,61 @@ For documentation see L. =back +=head2 LIBGUESTFS GOTCHAS + +L: "A feature of a +system [...] that works in the way it is documented but is +counterintuitive and almost invites mistakes." + +Since we developed libguestfs and the associated tools, there are +several things we would have designed differently, but are now stuck +with for backwards compatibility or other reasons. If there is ever a +libguestfs 2.0 release, you can expect these to change. Beware of +them. + +=over 4 + +=item Autosync / forgetting to sync. + +When modifying a filesystem from C or another language, you B +unmount all filesystems and call L explicitly before +you close the libguestfs handle. You can also call: + + guestfs_set_autosync (handle, 1); + +to have the unmount/sync done automatically for you when the handle is +closed. (This feature is called "autosync", L +q.v.) + +If you forget to do this, then it is entirely possible that your +changes won't be written out, or will be partially written, or (very +rarely) that you'll get disk corruption. + +Note that in L I. So quick and +dirty guestfish scripts that forget to sync will work just fine, which +can make this extra-puzzling if you are trying to debug a problem. + +=item Read-only should be the default. + +In L, I<--ro> should be the default, and you should +have to specify I<--rw> if you want to make changes to the image. + +This would reduce the potential to corrupt live VM images. + +Note that many filesystems change the disk when you just mount and +unmount, even if you didn't perform any writes. You need to use +C to guarantee that the disk is not changed. + +=item guestfish command line is hard to use. + +C doesn't do what people expect (open C +for examination). It tries to run a guestfish command C +which doesn't exist, so it fails, and it fails with a strange and +unintuitive error message. Like the Bourne shell, we should have used +C to run commands. + +=back + =head1 CONNECTION MANAGEMENT =head2 guestfs_h *