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| author | John Wilkins <john.wilkins@inktank.com> | 2013-09-16 18:38:55 -0700 |
|---|---|---|
| committer | John Wilkins <john.wilkins@inktank.com> | 2013-09-16 18:38:55 -0700 |
| commit | 874186bacc5e08efcdc50c4c315b5ef5a5bd4153 (patch) | |
| tree | 13ee8c40b791833b308324828bfe5eecd67b3cf8 | |
| parent | c9c710c1f41d7160950120cb550759a0adc66247 (diff) | |
| download | ceph-874186bacc5e08efcdc50c4c315b5ef5a5bd4153.tar.gz | |
doc: Updated the usage scenario and made a few syntax edits.
fixes: #6308
Signed-off-by: John Wilkins <john.wilkins@inktank.com>
| -rw-r--r-- | doc/man/8/crushtool.rst | 31 |
1 files changed, 17 insertions, 14 deletions
diff --git a/doc/man/8/crushtool.rst b/doc/man/8/crushtool.rst index 5a3fc09adc0..97303cc4bfa 100644 --- a/doc/man/8/crushtool.rst +++ b/doc/man/8/crushtool.rst @@ -7,8 +7,8 @@ Synopsis ======== -| **crushtool** ( -d *map* | -c *map.txt* | --build *numosds* - *layer1* *...* ) [ -o *outfile* [ --clobber ]] +| **crushtool** ( -d *map* | -c *map.txt* | --build --num_osds *numosds* + *layer1* *...* ) [ -o *outfile* ] Description @@ -41,9 +41,11 @@ The tool has four modes of operation. will create a relatively generic map with the given layer structure. See below for examples. -.. option:: --test ... +.. option:: --test + will perform a dry run of a CRUSH mapping for a range of input object - names, see crushtool --help for more information. + names, see crushtool --help for more information. + Options ======= @@ -52,10 +54,7 @@ Options will specify the output file. -.. option:: --clobber - - will allow the tool to overwrite an existing outfile (it will normally refuse). - + Building a map ============== @@ -83,22 +82,26 @@ preceding layer. Example ======= -Suppose we have 128 devices, each grouped into shelves with 4 devices -each, and 8 shelves per rack. We could create a three level hierarchy -with:: +Suppose we have two rows with two racks each and 20 nodes per rack. Suppose +each node contains 4 storage devices for Ceph OSD Daemons. This configuration +allows us to deploy 320 Ceph OSD Daemons. Lets assume a 42U rack with 2U nodes, +leaving an extra 2U for a rack switch. + +To reflect our hierarchy of devices, nodes, racks and rows, we would execute +the following:: - crushtool --build 128 shelf uniform 4 rack straw 8 root straw 0 -o map + crushtool -o crushmap --build --num_osds 320 node straw 4 rack straw 20 row straw 2 To adjust the default (generic) mapping rules, we can run:: # decompile - crushtool -d map -o map.txt + crushtool -d crushmap -o map.txt # edit vi map.txt # recompile - crushtool -c map.txt -o map + crushtool -c map.txt -o crushmap Availability |