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| author | Mikulas Patocka <mpatocka@redhat.com> | 2017-04-18 22:51:52 +0200 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2017-04-24 18:04:33 +0200 |
| commit | 9d609f85b7eb96697ae22ad1d47a3a3920174ba8 (patch) | |
| tree | 25610e72c2f7eff159c44c6afc8a88d080ee7447 /Documentation/device-mapper | |
| parent | dm integrity: various small changes and cleanups (diff) | |
| download | linux-9d609f85b7eb96697ae22ad1d47a3a3920174ba8.tar.xz linux-9d609f85b7eb96697ae22ad1d47a3a3920174ba8.zip | |
dm integrity: support larger block sizes
The DM integrity block size can now be 512, 1k, 2k or 4k. Using larger
blocks reduces metadata handling overhead. The block size can be
configured at table load time using the "block_size:<value>" option;
where <value> is expressed in bytes (defult is still 512 bytes).
It is safe to use larger block sizes with DM integrity, because the
DM integrity journal makes sure that the whole block is updated
atomically even if the underlying device doesn't support atomic writes
of that size (e.g. 4k block ontop of a 512b device).
Depends-on: 2859323e ("block: fix blk_integrity_register to use template's interval_exp if not 0")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'Documentation/device-mapper')
| -rw-r--r-- | Documentation/device-mapper/dm-integrity.txt | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/device-mapper/dm-integrity.txt b/Documentation/device-mapper/dm-integrity.txt index ced34cd915ef..f33e3ade7a09 100644 --- a/Documentation/device-mapper/dm-integrity.txt +++ b/Documentation/device-mapper/dm-integrity.txt @@ -136,6 +136,11 @@ journal_mac:algorithm(:key) (the key is optional) the journal. Thus, modified sector number would be detected at this stage. +block_size:number + The size of a data block in bytes. The larger the block size the + less overhead there is for per-block integrity metadata. + Supported values are 512, 1024, 2048 and 4096 bytes. If not + specified the default block size is 512 bytes. The journal mode (D/J), buffer_sectors, journal_watermark, commit_time can be changed when reloading the target (load an inactive table and swap the |