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Diffstat (limited to 'src/guestfs.pod')
| -rw-r--r-- | src/guestfs.pod | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/src/guestfs.pod b/src/guestfs.pod index dd419ac7..514db030 100644 --- a/src/guestfs.pod +++ b/src/guestfs.pod @@ -589,6 +589,29 @@ C<guestfish -c command> to run commands. =back +=head2 PROTOCOL LIMITS + +Internally libguestfs uses a message-based protocol to pass API calls +and their responses to and from a small "appliance" (see L</INTERNALS> +for plenty more detail about this). The maximum message size used by +the protocol is slightly less than 4 MB. For some API calls you may +need to be aware of this limit. The API calls which may be affected +are individually documented, with a link back to this section of the +documentation. + +A simple call such as C<guestfs_cat> returns its result (the file +data) in a simple string. Because this string is at some point +internally encoded as a message, the maximum size that it can return +is slightly under 4 MB. If the requested file is larger than this +then you will get an error. + +In order to transfer large files into and out of the guest filesystem, +you need to use particular calls that support this. The sections +L</UPLOADING> and L</DOWNLOADING> document how to do this. + +You might also consider mounting the disk image using our FUSE +filesystem support (L<guestmount(1)>). + =head1 CONNECTION MANAGEMENT =head2 guestfs_h * |