module Primary : V1_LWT.BLOCKmodule Secondary : V1_LWT.BLOCKinclude V1_LWT.BLOCKtype page_aligned_buffer = Cstruct.tThe type for page-aligned memory buffers.
type error = [ | `Unknown of stringan undiagnosed error
*)| `Unimplementedoperation not yet implemented in the code
*)| `Is_read_onlyyou cannot write to a read/only instance
*)| `Disconnectedthe device has been previously disconnected
*) ]The type for IO operation errors.
type info = {read_write : bool;True if we can write, false if read/only
*)sector_size : int;Octets per sector
*)size_sectors : int64;Total sectors per device
*)}Characteristics of the block device. Note some devices may be able to make themselves bigger over time.
val read :
t ->
int64 ->
page_aligned_buffer list ->
[ `Error of error | `Ok of unit ] ioread device sector_start buffers returns a blocking IO operation which attempts to fill buffers with data starting at sector_start. Each of buffers must be a whole number of sectors in length. The list of buffers can be of any length.
val write :
t ->
int64 ->
page_aligned_buffer list ->
[ `Error of error | `Ok of unit ] iowrite device sector_start buffers returns a blocking IO operation which attempts to write the data contained within buffers to t starting at sector_start. When the IO operation completes then all writes have been persisted.
Once submitted, it is not possible to cancel a request and there is no timeout.
The operation may fail with:
`Unimplemented: the operation has not been implemented, no data has been written.`Is_read_only: the device is read-only, no data has been written.`Disconnected: the device has been disconnected at application request, an unknown amount of data has been written.`Unknown: some other permanent, fatal error (e.g. disk is on fire), where an unknown amount of data has been written.Each of buffers must be a whole number of sectors in length. The list of buffers can be of any length.
The data will not be copied, so the supplied buffers must not be re-used until the IO operation completes.
val connect :
?progress_cb:([ `Percent of int | `Complete ] -> unit) ->
Primary.t ->
Secondary.t ->
[ `Ok of t | `Error of error ] Lwt.tconnect ?progress primary secondary creates a block device which performs I/O against primary, while building a mirror of primary on top of secondary in the background. Existing data in secondary will be destroyed.
If ?progress_cb is provided then it will be called on every percentage change in mirror progress.
It is an error if the block size of either primary or secondary is not an integer multiple of the other.
It is an error if primary and secondary have different lengths.
It is an error if secondary is read-only.
val string_of_error : error -> string