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cfs 1.7 KB

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  1. .TH CFS 4
  2. .SH NAME
  3. cfs \- cache file system
  4. .SH SYNOPSIS
  5. .B cfs
  6. .B -s
  7. .RB [ -rdS ]
  8. .RB [ -f
  9. .IR partition ]
  10. .PP
  11. .B cfs
  12. .B -a
  13. .I netaddr
  14. .RB [ -rdS ]
  15. .RB [ -f
  16. .IR partition ]
  17. .RI [ mtpt ]
  18. .SH DESCRIPTION
  19. .I Cfs
  20. is a user-level file server that caches information about remote
  21. files onto a local disk.
  22. It is normally started by the kernel at boot time, though users may start
  23. it manually.
  24. .I Cfs
  25. is interposed between the kernel and a network connection to a
  26. remote file server to improve the
  27. efficiency of access across slow network connections such as modem
  28. lines.
  29. On each open of a file
  30. .I cfs
  31. checks the consistency of cached information and discards any old
  32. information for that file.
  33. .PP
  34. .I Cfs
  35. mounts onto
  36. .I mtpt
  37. (default
  38. .BR / )
  39. after connecting to the file server.
  40. .PP
  41. The options are:
  42. .TP
  43. .B s
  44. the connection to the remote file server is on file
  45. descriptors 0 and 1.
  46. .TP
  47. .BI "a " netaddr
  48. dial the destination
  49. .I netaddr
  50. to connect to a remote file server.
  51. .TP
  52. .B r
  53. reformat the cache disk partition.
  54. .TP
  55. .B d
  56. turn on debugging.
  57. .TP
  58. .B S
  59. turn on statistics gathering. A file called
  60. .B cfsctl
  61. at the root of the caching file system can be read to get
  62. statistics concerning number of calls/bytes on client and server
  63. sides and latencies.
  64. .TP
  65. .BI "f " partition
  66. use file
  67. .I partition
  68. as the cache disk partition.
  69. .PP
  70. All 9P messages except
  71. .BR read ,
  72. .BR clone ,
  73. and
  74. .B walk
  75. (see
  76. .IR intro (5))
  77. are passed through
  78. .I cfs
  79. unchanged to the remote server.
  80. A
  81. .B clone
  82. followed immediately by a
  83. .B walk
  84. is converted into a
  85. .BR clwalk .
  86. If possible, a
  87. .B read
  88. is satisfied by cached data.
  89. Otherwise, the file server is queried for any missing data.
  90. .SH FILES
  91. .TP
  92. .B /dev/sdC0/cache
  93. Default file used for storing cached data.
  94. .SH SOURCE
  95. .B /sys/src/cmd/cfs