diff options
Diffstat (limited to 'Documentation/admin-guide')
| -rw-r--r-- | Documentation/admin-guide/device-mapper/dm-integrity.rst | 2 | ||||
| -rw-r--r-- | Documentation/admin-guide/device-mapper/index.rst | 1 | ||||
| -rw-r--r-- | Documentation/admin-guide/ext4.rst | 19 |
3 files changed, 13 insertions, 9 deletions
diff --git a/Documentation/admin-guide/device-mapper/dm-integrity.rst b/Documentation/admin-guide/device-mapper/dm-integrity.rst index 594095b54b29..c00f9f11e3f3 100644 --- a/Documentation/admin-guide/device-mapper/dm-integrity.rst +++ b/Documentation/admin-guide/device-mapper/dm-integrity.rst @@ -144,7 +144,7 @@ journal_crypt:algorithm(:key) (the key is optional) Encrypt the journal using given algorithm to make sure that the attacker can't read the journal. You can use a block cipher here (such as "cbc(aes)") or a stream cipher (for example "chacha20", - "salsa20", "ctr(aes)" or "ecb(arc4)"). + "salsa20" or "ctr(aes)"). The journal contains history of last writes to the block device, an attacker reading the journal could see the last sector nubmers diff --git a/Documentation/admin-guide/device-mapper/index.rst b/Documentation/admin-guide/device-mapper/index.rst index 4872fb6d2952..ec62fcc8eece 100644 --- a/Documentation/admin-guide/device-mapper/index.rst +++ b/Documentation/admin-guide/device-mapper/index.rst @@ -8,6 +8,7 @@ Device Mapper cache-policies cache delay + dm-clone dm-crypt dm-dust dm-flakey diff --git a/Documentation/admin-guide/ext4.rst b/Documentation/admin-guide/ext4.rst index 059ddcbe769d..9bc93f0ce0c9 100644 --- a/Documentation/admin-guide/ext4.rst +++ b/Documentation/admin-guide/ext4.rst @@ -181,14 +181,17 @@ When mounting an ext4 filesystem, the following option are accepted: system after its metadata has been committed to the journal. commit=nrsec (*) - Ext4 can be told to sync all its data and metadata every 'nrsec' - seconds. The default value is 5 seconds. This means that if you lose - your power, you will lose as much as the latest 5 seconds of work (your - filesystem will not be damaged though, thanks to the journaling). This - default value (or any low value) will hurt performance, but it's good - for data-safety. Setting it to 0 will have the same effect as leaving - it at the default (5 seconds). Setting it to very large values will - improve performance. + This setting limits the maximum age of the running transaction to + 'nrsec' seconds. The default value is 5 seconds. This means that if + you lose your power, you will lose as much as the latest 5 seconds of + metadata changes (your filesystem will not be damaged though, thanks + to the journaling). This default value (or any low value) will hurt + performance, but it's good for data-safety. Setting it to 0 will have + the same effect as leaving it at the default (5 seconds). Setting it + to very large values will improve performance. Note that due to + delayed allocation even older data can be lost on power failure since + writeback of those data begins only after time set in + /proc/sys/vm/dirty_expire_centisecs. barrier=<0|1(*)>, barrier(*), nobarrier This enables/disables the use of write barriers in the jbd code. |