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Diffstat (limited to 'Documentation/MANPAGE.md')
| -rw-r--r-- | Documentation/MANPAGE.md | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/Documentation/MANPAGE.md b/Documentation/MANPAGE.md index 9446f0b..aa40922 100644 --- a/Documentation/MANPAGE.md +++ b/Documentation/MANPAGE.md @@ -106,6 +106,22 @@ Options: : Allow mounting over non-empty directories. FUSE by default disallows this to prevent accidential shadowing of files. +**-noprealloc** +: Disable preallocation before writing. By default, gocryptfs + preallocates the space the next write will take using fallocate(2) + in mode FALLOC_FL_KEEP_SIZE. The preallocation makes sure it cannot + run out of space in the middle of the write, which would cause the + last 4kB block to be corrupt and unreadable. + + On ext4, preallocation is fast and does not cause a + noticeable performance hit. Unfortunately, on Btrfs, preallocation + is very slow, especially on rotational HDDs. The "-noprealloc" + option gives users the choice to trade robustness against + out-of-space errors for a massive speedup. + + For benchmarks and more details of the issue see + https://github.com/rfjakob/gocryptfs/issues/63 . + **-nosyslog** : Diagnostic messages are normally redirected to syslog once gocryptfs daemonizes. This option disables the redirection and messages will @@ -197,4 +213,4 @@ Mount an ecrypted view of joe's home directory using reverse mode: SEE ALSO ======== -fuse(8) +fuse(8) fallocate(2) |