package nbd

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Parameters
Signature

package nbd

nbd
- Nbd
  - Channel
  - Client
  - Mirror
    
    Make
    
    Primary
    
    Secondary
  - Mux
    
    Make
    
    R
    
    RPC
  - Protocol
    
    Announcement
    
    ClientFlag
    
    Command
    
    DiskInfo
    
    Error
    
    ExportName
    
    GlobalFlag
    
    Negotiate
    
    NegotiateResponse
    
    Option
    
    OptionRequestHeader
    
    OptionResponse
    
    OptionResponseHeader
    
    PerExportFlag
    
    Reply
    
    Request
    
    Server
  - S
    
    CLIENT
    
    SERVER
  - Server

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Class type

Parameters

module Primary : Mirage_block_lwt.S

module Secondary : Mirage_block_lwt.S

Signature

include Mirage_block_lwt.S

type page_aligned_buffer = Cstruct.t

The type for page-aligned memory buffers.

type error = private [>

| Mirage_device.error

]

The type for block errors.

val pp_error : error Fmt.t

pp_error is the pretty-printer for errors.

type write_error = private [>

| Mirage_device.error
| `Is_read_only

]

The type for write errors.

val pp_write_error : write_error Fmt.t

pp_write_error is the pretty-printer for write errors.

include Mirage_device.S with type 'a io = 'a Lwt.t

type 'a io = 'a Lwt.t

The type for potentially blocking I/O operation

type t

The type representing the internal state of the device

val disconnect : t -> unit io

Disconnect from the device. While this might take some time to complete, it can never result in an error.

val get_info : t -> Mirage_block.info io

Query the characteristics of a specific block device

val read : 
  t ->
  int64 ->
  page_aligned_buffer list ->
  (unit, error) Stdlib.result io

read device sector_start buffers reads data starting at sector_start from the block device into buffers. Ok () means the buffers have been filled. Error _ indicates an I/O error has happened and some of the buffers may not be filled. Each of elements in the list 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 ->
  (unit, write_error) Stdlib.result io

write device sector_start buffers writes data from buffers onto the block device starting at sector_start. Ok () means the contents of the buffers have been written. Error _ indicates a partial failure in which some of the writes may not have happened.

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.

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 ->
  t Lwt.t

connect ?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