Monday, May 2, 2011

GlusterFS defaults

I recently came across a question in the Gluster mailing list which discussed about default options set for the translators. The command `gluster volume info' lists the options re-configured. But there is no way to know the default configurations (as of now), other than to check the volume files and the code.
I have listed the default options below. All the options are as of 3.2.x and applies to 3.1.x.
GlusterFS servers by default have the following translators enabled 
  • features/access-control
  • features/locks
  • performance/io-threads
  • features/marker
  • debug/io-stats
Client has the following performance translators enabled by default
  • performance/write-behind
  • performance/read-ahead
  • performance/io-cache
  • performance/quick-read
  • performance/stat-prefetch
  • debug/io-stats
Below, I've listed the default options that are set for the above translators.
Server translator defaults
features/locks
trace off
performance/io-threads
  • thread-count 16 (minimun 1, maximum 64)
  • idle-time 1
features/marker 
  • volume-uuid - UUID of the volume
  • timestamp-file - path
  • xtime - off
  • quota - off
debug/io-stats
  • dump-fd-stats off
  • latency-measurement off
  • count-fop-hits off
  • log-level INFO
Client translator defaults:   
performance/write-behind
  • flush-behind on
  • cache-size/window-size 1MB (Min 512KB, Max 1GB)
  • disable-for-first-nbytes 0
  • enable-O_SYNC disabled by default
  • enable-trickling-writes on
performance/read-ahead
  • force-atime-update false
  • page-count 4 (Min 1, Max 16)
  • performance/io-cache
    • priority 1
    • cache-timeout/force-revalidate-timeout 1sec (min 0, max 60)
    • cache-size 32MB (min 4MB, max 6GB)
    • min-file-size 0
    • max-file-size -1 (Limited by the underlying FS)
    performance/quick-read
    • priority 1 cache-size 128MB (min 0, max 6GB)
    • cache-timeout 1 (min 1, max 60)
    • max-file-size 64KB (min 0, max 1MB)
    performance/stat-prefetch
    This translator does not have any options to configure.