diff options
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/device-mapper/dm-crypt.txt | 7 | ||||
-rw-r--r-- | Documentation/device-mapper/dm-raid.txt | 70 |
2 files changed, 76 insertions, 1 deletions
diff --git a/Documentation/device-mapper/dm-crypt.txt b/Documentation/device-mapper/dm-crypt.txt index 524de926290d..59293ac4a5d0 100644 --- a/Documentation/device-mapper/dm-crypt.txt +++ b/Documentation/device-mapper/dm-crypt.txt | |||
@@ -8,7 +8,7 @@ Parameters: <cipher> <key> <iv_offset> <device path> <offset> | |||
8 | 8 | ||
9 | <cipher> | 9 | <cipher> |
10 | Encryption cipher and an optional IV generation mode. | 10 | Encryption cipher and an optional IV generation mode. |
11 | (In format cipher-chainmode-ivopts:ivmode). | 11 | (In format cipher[:keycount]-chainmode-ivopts:ivmode). |
12 | Examples: | 12 | Examples: |
13 | des | 13 | des |
14 | aes-cbc-essiv:sha256 | 14 | aes-cbc-essiv:sha256 |
@@ -20,6 +20,11 @@ Parameters: <cipher> <key> <iv_offset> <device path> <offset> | |||
20 | Key used for encryption. It is encoded as a hexadecimal number. | 20 | Key used for encryption. It is encoded as a hexadecimal number. |
21 | You can only use key sizes that are valid for the selected cipher. | 21 | You can only use key sizes that are valid for the selected cipher. |
22 | 22 | ||
23 | <keycount> | ||
24 | Multi-key compatibility mode. You can define <keycount> keys and | ||
25 | then sectors are encrypted according to their offsets (sector 0 uses key0; | ||
26 | sector 1 uses key1 etc.). <keycount> must be a power of two. | ||
27 | |||
23 | <iv_offset> | 28 | <iv_offset> |
24 | The IV offset is a sector count that is added to the sector number | 29 | The IV offset is a sector count that is added to the sector number |
25 | before creating the IV. | 30 | before creating the IV. |
diff --git a/Documentation/device-mapper/dm-raid.txt b/Documentation/device-mapper/dm-raid.txt new file mode 100644 index 000000000000..33b6b7071ac8 --- /dev/null +++ b/Documentation/device-mapper/dm-raid.txt | |||
@@ -0,0 +1,70 @@ | |||
1 | Device-mapper RAID (dm-raid) is a bridge from DM to MD. It | ||
2 | provides a way to use device-mapper interfaces to access the MD RAID | ||
3 | drivers. | ||
4 | |||
5 | As with all device-mapper targets, the nominal public interfaces are the | ||
6 | constructor (CTR) tables and the status outputs (both STATUSTYPE_INFO | ||
7 | and STATUSTYPE_TABLE). The CTR table looks like the following: | ||
8 | |||
9 | 1: <s> <l> raid \ | ||
10 | 2: <raid_type> <#raid_params> <raid_params> \ | ||
11 | 3: <#raid_devs> <meta_dev1> <dev1> .. <meta_devN> <devN> | ||
12 | |||
13 | Line 1 contains the standard first three arguments to any device-mapper | ||
14 | target - the start, length, and target type fields. The target type in | ||
15 | this case is "raid". | ||
16 | |||
17 | Line 2 contains the arguments that define the particular raid | ||
18 | type/personality/level, the required arguments for that raid type, and | ||
19 | any optional arguments. Possible raid types include: raid4, raid5_la, | ||
20 | raid5_ls, raid5_rs, raid6_zr, raid6_nr, and raid6_nc. (raid1 is | ||
21 | planned for the future.) The list of required and optional parameters | ||
22 | is the same for all the current raid types. The required parameters are | ||
23 | positional, while the optional parameters are given as key/value pairs. | ||
24 | The possible parameters are as follows: | ||
25 | <chunk_size> Chunk size in sectors. | ||
26 | [[no]sync] Force/Prevent RAID initialization | ||
27 | [rebuild <idx>] Rebuild the drive indicated by the index | ||
28 | [daemon_sleep <ms>] Time between bitmap daemon work to clear bits | ||
29 | [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization | ||
30 | [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization | ||
31 | [max_write_behind <sectors>] See '-write-behind=' (man mdadm) | ||
32 | [stripe_cache <sectors>] Stripe cache size for higher RAIDs | ||
33 | |||
34 | Line 3 contains the list of devices that compose the array in | ||
35 | metadata/data device pairs. If the metadata is stored separately, a '-' | ||
36 | is given for the metadata device position. If a drive has failed or is | ||
37 | missing at creation time, a '-' can be given for both the metadata and | ||
38 | data drives for a given position. | ||
39 | |||
40 | NB. Currently all metadata devices must be specified as '-'. | ||
41 | |||
42 | Examples: | ||
43 | # RAID4 - 4 data drives, 1 parity | ||
44 | # No metadata devices specified to hold superblock/bitmap info | ||
45 | # Chunk size of 1MiB | ||
46 | # (Lines separated for easy reading) | ||
47 | 0 1960893648 raid \ | ||
48 | raid4 1 2048 \ | ||
49 | 5 - 8:17 - 8:33 - 8:49 - 8:65 - 8:81 | ||
50 | |||
51 | # RAID4 - 4 data drives, 1 parity (no metadata devices) | ||
52 | # Chunk size of 1MiB, force RAID initialization, | ||
53 | # min recovery rate at 20 kiB/sec/disk | ||
54 | 0 1960893648 raid \ | ||
55 | raid4 4 2048 min_recovery_rate 20 sync\ | ||
56 | 5 - 8:17 - 8:33 - 8:49 - 8:65 - 8:81 | ||
57 | |||
58 | Performing a 'dmsetup table' should display the CTR table used to | ||
59 | construct the mapping (with possible reordering of optional | ||
60 | parameters). | ||
61 | |||
62 | Performing a 'dmsetup status' will yield information on the state and | ||
63 | health of the array. The output is as follows: | ||
64 | 1: <s> <l> raid \ | ||
65 | 2: <raid_type> <#devices> <1 health char for each dev> <resync_ratio> | ||
66 | |||
67 | Line 1 is standard DM output. Line 2 is best shown by example: | ||
68 | 0 1960893648 raid raid4 5 AAAAA 2/490221568 | ||
69 | Here we can see the RAID type is raid4, there are 5 devices - all of | ||
70 | which are 'A'live, and the array is 2/490221568 complete with recovery. | ||