1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
|
==============================================================================
NTFS-3G has been installed, and was built with UBLIO support.
The UBLIO layer is configured through environment variables, which are read
when mounting the filesystem. The following are available:
NTFS_USE_UBLIO - Enable the UBLIO cache.
UBLIO_BLOCKSIZE - Actual reads/writes will be multiples of this quantity.
UBLIO_ITEMS - Number of cache entries, each of UBLIO_BLOCKSIZE length.
UBLIO_GRACE - Number of times a cache entry will refuse being recycled.
UBLIO_SYNC_IO - If enabled, all writes will be immediatly executed.
To give an idea about tuning, here are the default values with some notes
(they are only based on some simple benchmarks, and may be wrong):
NTFS_USE_UBLIO - 1. Disabling it drastically decreases performance.
UBLIO_BLOCKSIZE - 262144 (256KB). Larger improves reading/writing speed of
large files, and smaller makes filesystem operations
(creation, deletion, moving, find(1)) perform faster.
Try 2/4MB and 512/256KB for the different approaches. Note
that after that points performance descreases again.
UBLIO_ITEMS - 64. Higher increases speed of filesystem operations. Try 128.
UBLIO_GRACE - 32. Makes the cache items have more chances to be reused.
UBLIO_SYNC_IO - 0. If enabled, highly decreases writing speed, but the data
is immediatly written to the disk.
For example (improves performance over large files):
# env UBLIO_BLOCKSIZE=2097152 ntfs-3g /dev/ad0s1 /mnt
Alternatively these variables could be set in the shell startup file. For
example if you are using it in /etc/fstab add it to /etc/profile. In that
case, use "ntfs-3g" as the type.
It is also possible to enforce block aligned I/O on regular files by setting
the FORCE_ALIGNED_IO variable (it will be set to 512 bytes), but this is only
useful for testing purposes and in practice has no use.
Note that higher values for UBLIO_BLOCKSIZE and UBLIO_ITEMS increase the
memory usage by their product in bytes. By default it consumes 64MB. To
decrease it to 16MB set UBLIO_BLOCKSIZE to 256KB for example.
When doing many simultaneous file operations sometimes one of them fails. The
greater UBLIO_BLOCKSIZE is, more chances this has to happen. Small values like
4096 also work fine.
==============================================================================
|
