source: 2018/23/JesseS/JesseS/db/fsfs.conf @ 9601

Revision 9601, 6.8 KB checked in by osedcald, 21 months ago (diff)
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1### This file controls the configuration of the FSFS filesystem.
2
3[memcached-servers]
4### These options name memcached servers used to cache internal FSFS
5### data.  See http://www.danga.com/memcached/ for more information on
6### memcached.  To use memcached with FSFS, run one or more memcached
7### servers, and specify each of them as an option like so:
8# first-server = 127.0.0.1:11211
9# remote-memcached = mymemcached.corp.example.com:11212
10### The option name is ignored; the value is of the form HOST:PORT.
11### memcached servers can be shared between multiple repositories;
12### however, if you do this, you *must* ensure that repositories have
13### distinct UUIDs and paths, or else cached data from one repository
14### might be used by another accidentally.  Note also that memcached has
15### no authentication for reads or writes, so you must ensure that your
16### memcached servers are only accessible by trusted users.
17
18[caches]
19### When a cache-related error occurs, normally Subversion ignores it
20### and continues, logging an error if the server is appropriately
21### configured (and ignoring it with file:// access).  To make
22### Subversion never ignore cache errors, uncomment this line.
23# fail-stop = true
24
25[rep-sharing]
26### To conserve space, the filesystem can optionally avoid storing
27### duplicate representations.  This comes at a slight cost in
28### performance, as maintaining a database of shared representations can
29### increase commit times.  The space savings are dependent upon the size
30### of the repository, the number of objects it contains and the amount of
31### duplication between them, usually a function of the branching and
32### merging process.
33###
34### The following parameter enables rep-sharing in the repository.  It can
35### be switched on and off at will, but for best space-saving results
36### should be enabled consistently over the life of the repository.
37### 'svnadmin verify' will check the rep-cache regardless of this setting.
38### rep-sharing is enabled by default.
39# enable-rep-sharing = true
40
41[deltification]
42### To conserve space, the filesystem stores data as differences against
43### existing representations.  This comes at a slight cost in performance,
44### as calculating differences can increase commit times.  Reading data
45### will also create higher CPU load and the data will be fragmented.
46### Since deltification tends to save significant amounts of disk space,
47### the overall I/O load can actually be lower.
48###
49### The options in this section allow for tuning the deltification
50### strategy.  Their effects on data size and server performance may vary
51### from one repository to another.  Versions prior to 1.8 will ignore
52### this section.
53###
54### The following parameter enables deltification for directories. It can
55### be switched on and off at will, but for best space-saving results
56### should be enabled consistently over the life of the repository.
57### Repositories containing large directories will benefit greatly.
58### In rarely read repositories, the I/O overhead may be significant as
59### cache hit rates will most likely be low
60### directory deltification is disabled by default.
61# enable-dir-deltification = false
62###
63### The following parameter enables deltification for properties on files
64### and directories.  Overall, this is a minor tuning option but can save
65### some disk space if you merge frequently or frequently change node
66### properties.  You should not activate this if rep-sharing has been
67### disabled because this may result in a net increase in repository size.
68### property deltification is disabled by default.
69# enable-props-deltification = false
70###
71### During commit, the server may need to walk the whole change history of
72### of a given node to find a suitable deltification base.  This linear
73### process can impact commit times, svnadmin load and similar operations.
74### This setting limits the depth of the deltification history.  If the
75### threshold has been reached, the node will be stored as fulltext and a
76### new deltification history begins.
77### Note, this is unrelated to svn log.
78### Very large values rarely provide significant additional savings but
79### can impact performance greatly - in particular if directory
80### deltification has been activated.  Very small values may be useful in
81### repositories that are dominated by large, changing binaries.
82### Should be a power of two minus 1.  A value of 0 will effectively
83### disable deltification.
84### For 1.8, the default value is 1023; earlier versions have no limit.
85# max-deltification-walk = 1023
86###
87### The skip-delta scheme used by FSFS tends to repeatably store redundant
88### delta information where a simple delta against the latest version is
89### often smaller.  By default, 1.8+ will therefore use skip deltas only
90### after the linear chain of deltas has grown beyond the threshold
91### specified by this setting.
92### Values up to 64 can result in some reduction in repository size for
93### the cost of quickly increasing I/O and CPU costs. Similarly, smaller
94### numbers can reduce those costs at the cost of more disk space.  For
95### rarely read repositories or those containing larger binaries, this may
96### present a better trade-off.
97### Should be a power of two.  A value of 1 or smaller will cause the
98### exclusive use of skip-deltas (as in pre-1.8).
99### For 1.8, the default value is 16; earlier versions use 1.
100# max-linear-deltification = 16
101
102[packed-revprops]
103### This parameter controls the size (in kBytes) of packed revprop files.
104### Revprops of consecutive revisions will be concatenated into a single
105### file up to but not exceeding the threshold given here.  However, each
106### pack file may be much smaller and revprops of a single revision may be
107### much larger than the limit set here.  The threshold will be applied
108### before optional compression takes place.
109### Large values will reduce disk space usage at the expense of increased
110### latency and CPU usage reading and changing individual revprops.  They
111### become an advantage when revprop caching has been enabled because a
112### lot of data can be read in one go.  Values smaller than 4 kByte will
113### not improve latency any further and quickly render revprop packing
114### ineffective.
115### revprop-pack-size is 64 kBytes by default for non-compressed revprop
116### pack files and 256 kBytes when compression has been enabled.
117# revprop-pack-size = 64
118###
119### To save disk space, packed revprop files may be compressed.  Standard
120### revprops tend to allow for very effective compression.  Reading and
121### even more so writing, become significantly more CPU intensive.  With
122### revprop caching enabled, the overhead can be offset by reduced I/O
123### unless you often modify revprops after packing.
124### Compressing packed revprops is disabled by default.
125# compress-packed-revprops = false
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