error "%s: file is too small to be a disk image (%Ld bytes)"
outfile outsize
-(* Build a data structure describing the source disk's partition layout. *)
+(* Get the source partition type. *)
+type parttype = MBR | GPT (* Only these are supported by virt-resize. *)
+
+let parttype, parttype_string =
+ let pt = g#part_get_parttype "/dev/sda" in
+ if debug then eprintf "partition table type: %s\n%!" pt;
+
+ match pt with
+ | "msdos" -> MBR, "msdos"
+ | "gpt" -> GPT, "gpt"
+ | _ ->
+ error "%s: unknown partition table type\nvirt-resize only supports MBR (DOS) and GPT partition tables." infile
+
+(* Build a data structure describing the source disk's partition layout.
+ *
+ * NOTE: For MBR, only primary/extended partitions are tracked here.
+ * Logical partitions are contained within an extended partition, and
+ * we don't track them (they are just copied within the extended
+ * partition). For the same reason we cannot resize logical partitions.
+ *)
type partition = {
p_name : string; (* Device name, like /dev/sda1. *)
p_part : G.partition; (* SOURCE partition data from libguestfs. *)
| ContentUnknown (* undetermined *)
| ContentPV of int64 (* physical volume (size of PV) *)
| ContentFS of string * int64 (* mountable filesystem (FS type, FS size) *)
+ | ContentExtendedPartition (* MBR extended partition *)
and partition_operation =
| OpCopy (* copy it as-is, no resizing *)
| OpIgnore (* ignore it (create on target, but don't
| ContentUnknown -> "unknown data"
| ContentPV sz -> sprintf "LVM PV (%Ld bytes)" sz
| ContentFS (fs, sz) -> sprintf "filesystem %s (%Ld bytes)" fs sz
+ | ContentExtendedPartition -> "extended partition"
and string_of_partition_content_no_size = function
| ContentUnknown -> "unknown data"
| ContentPV _ -> sprintf "LVM PV"
| ContentFS (fs, _) -> sprintf "filesystem %s" fs
+ | ContentExtendedPartition -> "extended partition"
let get_partition_content =
let pvs_full = Array.to_list (g#pvs_full ()) in
with
G.Error _ -> ContentUnknown
+let is_extended_partition = function
+ | Some (0x05|0x0f) -> true
+ | _ -> false
+
let partitions : partition list =
let parts = Array.to_list (g#part_list "/dev/sda") in
if List.length parts = 0 then
error "the source disk has no partitions";
+ (* Filter out logical partitions. See note above. *)
+ let parts =
+ match parttype with
+ | GPT -> parts
+ | MBR ->
+ List.filter (function
+ | { G.part_num = part_num } when part_num >= 5_l -> false
+ | _ -> true
+ ) parts in
+
let partitions =
List.map (
fun ({ G.part_num = part_num } as part) ->
let mbr_id =
try Some (g#part_get_mbr_id "/dev/sda" part_num)
with G.Error _ -> None in
- let typ = get_partition_content name in
+ let typ =
+ if is_extended_partition mbr_id then ContentExtendedPartition
+ else get_partition_content name in
{ p_name = name; p_part = part;
p_bootable = bootable; p_mbr_id = mbr_id; p_type = typ;
lv_type : logvol_content;
mutable lv_operation : logvol_operation
}
-and logvol_content = partition_content (* except ContentPV cannot occur *)
+ (* ContentPV, ContentExtendedPartition cannot occur here *)
+and logvol_content = partition_content
and logvol_operation =
| LVOpNone (* nothing *)
| LVOpExpand (* expand it *)
let lvs = List.map (
fun name ->
let typ = get_partition_content name in
- assert (match typ with ContentPV _ -> false | _ -> true);
+ assert (
+ match typ with ContentPV _ | ContentExtendedPartition -> false
+ | _ -> true
+ );
{ lv_name = name; lv_type = typ; lv_operation = LVOpNone }
) lvs in
| ContentFS (("ntfs"), _) when !ntfs_available -> true
| ContentFS (("btrfs"), _) when !btrfs_available -> true
| ContentFS (_, _) -> false
+ | ContentExtendedPartition -> false
else
fun _ -> false
| ContentFS (("ntfs"), _) when !ntfs_available -> NTFSResize
| ContentFS (("btrfs"), _) when !btrfs_available -> BtrfsFilesystemResize
| ContentFS (_, _) -> assert false
+ | ContentExtendedPartition -> assert false
else
fun _ -> assert false
error "%s: This partition has contains a %s filesystem which will be damaged by shrinking it below %Ld bytes (user asked to shrink it to %Ld bytes). If you want to shrink this partition, you need to use the '--resize-force' option, but that could destroy any data on this partition. (This error came from '%s' option on the command line.)"
name fstype size newsize option
| ContentFS _ -> ()
+ | ContentExtendedPartition ->
+ error "%s: This extended partition contains logical partitions which might be damaged by shrinking it. If you want to shrink this partition, you need to use the '--resize-force' option, but that could destroy logical partitions within this partition. (This error came from '%s' option on the command line.)"
+ name option
);
p.p_operation <- OpResize newsize
* carefully move the backup GPT (and rewrite those references) or
* recreate the whole partition table from scratch.
*)
-let g, parttype =
- let parttype = g#part_get_parttype "/dev/sda" in
- if debug then eprintf "partition table type: %s\n%!" parttype;
-
+let g =
(* Try hard to initialize the partition table. This might involve
* relaunching another handle.
*)
let last_error = ref "" in
let rec initialize_partition_table g attempts =
let ok =
- try g#part_init "/dev/sdb" parttype; true
+ try g#part_init "/dev/sdb" parttype_string; true
with G.Error error -> last_error := error; false in
if ok then g, true
else if attempts > 0 then (
if not ok then
error "Failed to initialize the partition table on the target disk. You need to wipe or recreate the target disk and then run virt-resize again.\n\nThe underlying error was: %s" !last_error;
- g, parttype
+ g
(* Copy the bootloader across.
* Don't disturb the partition table that we just wrote.
ignore (g#pwrite_device "/dev/sdb" bootsect 0L);
let start =
- if parttype <> "gpt" then 512L
+ if parttype <> GPT then 512L
else
(* XXX With 4K sectors does GPT just fit more entries in a
* sector, or does it always use 34 sectors?
(* Are we going to align the first partition and fix the bootloader? *)
let align_first_partition_and_fix_bootloader =
- (* Bootloaders that we know how to fix. *)
- let can_fix_boot_loader =
+ (* Bootloaders that we know how to fix:
+ * - first partition is NTFS, and
+ * - first partition is bootable, and
+ * - only one partition (ie. not Win Vista and later), and
+ * - it's not already aligned to some small value (no point
+ * moving it around unnecessarily)
+ *)
+ let rec can_fix_boot_loader () =
match partitions with
- | { p_type = ContentFS ("ntfs", _); p_bootable = true;
- p_operation = OpCopy | OpIgnore | OpResize _ } :: _ -> true
+ | [ { p_part = { G.part_start = start };
+ p_type = ContentFS ("ntfs", _);
+ p_bootable = true;
+ p_operation = OpCopy | OpIgnore | OpResize _ } ]
+ when not_aligned_enough start -> true
| _ -> false
+ and not_aligned_enough start =
+ let alignment = alignment_of start in
+ alignment < 12 (* < 4K alignment *)
+ and alignment_of = function
+ | 0L -> 64
+ | n when n &^ 1L = 1L -> 0
+ | n -> 1 + alignment_of (n /^ 2L)
in
- match align_first, can_fix_boot_loader with
+ match align_first, can_fix_boot_loader () with
| `Never, _
| `Auto, false -> false
| `Always, _
| `Auto, true -> true
+let () =
+ if debug then
+ eprintf "align_first_partition_and_fix_bootloader = %b\n%!"
+ align_first_partition_and_fix_bootloader
+
(* Repartition the target disk. *)
(* Calculate the location of the partitions on the target disk. This
let () =
List.iter (
fun p ->
- g#part_add "/dev/sdb" "primary" p.p_target_start p.p_target_end;
-
- (* Set bootable and MBR IDs *)
- if p.p_bootable then
- g#part_set_bootable "/dev/sdb" p.p_target_partnum true;
-
- (match p.p_mbr_id with
- | None -> ()
- | Some mbr_id ->
- g#part_set_mbr_id "/dev/sdb" p.p_target_partnum mbr_id
- );
+ g#part_add "/dev/sdb" "primary" p.p_target_start p.p_target_end
) partitions
(* Copy over the data. *)
if not quiet then
printf "Copying %s ...\n%!" source;
- g#copy_size source target copysize;
-
+ (match p.p_type with
+ | ContentUnknown | ContentPV _ | ContentFS _ ->
+ g#copy_device_to_device ~size:copysize source target
+
+ | ContentExtendedPartition ->
+ (* You can't just copy an extended partition by name, eg.
+ * source = "/dev/sda2", because the device name only covers
+ * the first 1K of the partition. Instead, copy the
+ * source bytes from the parent disk (/dev/sda).
+ *)
+ let srcoffset = p.p_part.G.part_start in
+ g#copy_device_to_device ~srcoffset ~size:copysize "/dev/sda" target
+ )
| _ -> ()
) partitions
+(* Set bootable and MBR IDs. Do this *after* copying over the data,
+ * so that we can magically change the primary partition to an extended
+ * partition if necessary.
+ *)
+let () =
+ List.iter (
+ fun p ->
+ if p.p_bootable then
+ g#part_set_bootable "/dev/sdb" p.p_target_partnum true;
+
+ (match p.p_mbr_id with
+ | None -> ()
+ | Some mbr_id ->
+ g#part_set_mbr_id "/dev/sdb" p.p_target_partnum mbr_id
+ );
+ ) partitions
+
(* Fix the bootloader if we aligned the first partition. *)
let () =
if align_first_partition_and_fix_bootloader then (
git.annexia.org / libguestfs.git / blobdiff