1993.1.26

SUBJECT: NFSÀÇ °³³ä

DESCRIPTION:
0. NetworkÀ» °æÀ¯ÇÑ file Àü¼Û °æ·Î
   0) remote machineÀÇ fileÀ» °¡Á® ¿Â´Ù.

                    Local Machine              | Network |             Remote Machine
                                               |         |
             +-----------+     +-----------+   |         |   +-----------+     +-----------+
             | file Àü¼Û |¦¡¡æ |  Network  |¦¡¦¡¦¡¦¡¦¡¦¡¦¡¡æ |  Network  | ¦¡¡æ| file Àü¼Û |¦¡¦¡¦¤
             |  Client   |     |   S/W     |   |         |   |   S/W     |     |  Server   |    ¡éDisk
             +-----------+     +-----------+   |         |   +-----------+     +-----------+ +-------+
                                               |         |                                   |  file |
                                                                                             +-------+
                                               |         |
             +-----------+data +-----------+   |  data   |   +-----------+data +-----------+
         ¦£¦¡| file Àü¼Û |¡ç¦¡ |  Network  |¡ç¦¡¦¡¦¡¦¡¦¡¦¡¦¡ |  Network  |¡ç¦¡ | file Àü¼Û |¡ç¦¡¦¤
     Disk¦¢  |  Client   |     |   S/W     |   |         |   |   S/W     |     |  Server   |    ¦¢Disk
         ¡é  +-----------+     +-----------+   |         |   +-----------+     +-----------+ +-------+
       +-------+                               |         |                                   |  file |
       |  file |                               |         |                                   +-------+
       +-------+                               |         |                                    

   1) fileÀÇ data¸¦ ó¸®ÇÑ´Ù.

      +-----------+          +----------+          +---------------+
      |   local   |¦¡¦¡¦¡¦¡¡æ|   file   |¦¡¦¡¦¡¦¡¡æ|  application  |
      |   file    |¡ç¦¡¦¡¦¡¦¡|  system  |¡ç¦¡¦¡¦¡¦¡|    software   |
      +-----------+          +----------+          +---------------+

   2) ó¸®µÈ fileÀ» º»·¡·Î µÇµ¹¸°´Ù.

                    Local Machine              | Network |             Remote Machine
                                               |         |
             +-----------+data +-----------+   |  data   |   +-----------+data +-----------+
             | file Àü¼Û |¦¡¡æ |  Network  |¦¡¦¡¦¡¦¡¦¡¦¡¦¡¡æ |  Network  | ¦¡¡æ| file Àü¼Û |¦¡¦¡¦¤
             |  Client   |     |   S/W     |   |         |   |   S/W     |     |  Server   |    ¡éDisk
             +-----------+     +-----------+   |         |   +-----------+     +-----------+ +-------+
                                               |         |                                   |  file |
                                                                                             +-------+

1. ÀÚ¿ø °øÀ¯Çü networkÀÇ Àü´Þ °æ·Î

           Local Machine                    | Network |             Remote Machine
                                            |         |
    +--------+     +--------+    +--------+ |         |     +-----------+
    | ÀÀ ¿ë  |¦¡¡æ |  File  |¦¡¡æ|Network |¦¡¦¡¦¡¦¡¦¡¦¡¦¡¡æ |  Network  |¦¡¦¡¦¤
    |  S/W   |¡ç¦¡ | System |¦¡¦¤|  S/W   | |         |     |   S/W     |    ¦¢
    +--------+     +--------+  ¦¢+--------+ |         |     +-----------+    ¡é
                               ¡é           |         |                 +--------------+ 
                          +---------+       |         |                 |    Remote    |     
                          |  Local  |       |         |                 | file service |
                          |  file   |       |         |                 +--------------+
                          +---------+       |         |

2. ÀÚ¿ø °øÀ¯Çü networkÀÇ Software ±¸¼º

              Client
    +--------------------------------+
    |        Application S/W         |
    +-----------------¦½-------------+
                      ¦­                                         Server
    +-----------------¦À-------------+            +-------------------------------------+
    | +---------------¦À-----------+ |            | +-------------+    +--------------+ |
    | |       ¦®¦¬¦¬¦¬¦µ¦¬¦¬¦¬¦¯   | |            | |             |    |              | |
    | +-------¦À----------+   ¦­   | |            | | Remote File |    |  Local File  | |
    | +-------¦À--------+ | Remote | |            | |    Server   |    |    Server    | |
    | |       ¦­        | | File   | |            | |       ¦®¦¬¦¬¦¬¦¬¦¬¦¬¦¬¦¬¦¯      | |
    | |   Local File    | | °ü¸®   | |            | +-------¦À----+    +------¦À------+ |
    | |      °ü¸®       | |   ¦­   | |            | +-------¦À----+    +------¦À------+ |
    | |       ¦­        | |   ¦­   | |            | |       ¦­    |    |      ¦­      | |
    | +-------¦À--------+ +---¦À---+ |            | |       ¦­    |    |      ¦­      | |
    | +-------¦À--------+ +---¦À---+ |            | |   Network   |    |  Hard Disk   | |
    | |       ¦­        | |   ¦­   | |            | |   󸮺Π   |    |     Á¦¾î     | |
    | |    Hard Disk    | | Network| |            | |       ¦­    |    |      ¦­      | |
    | |      °ü¸®       | | 󸮺Π| |            | |       ¦­    |    |      ¦­      | |
    | |       ¦­        | |   ¦­   | |            | |       ¦­    |    |      ¦­      | |
    | +----+--¦À--------+ +---¦À¦¨-+ |            | +---¦¨--¦À----+    +------¦À--+---+ |
    +------|--¦À--------------¦À¦«----+           +-----¦«--¦À----------------¦À--|-----+
           |  ¦­              ¦­¦¢                      ¦¢  ¦­                ¦­  |
           |  ¡é              ¦­¦¢                      ¦¢  ¦­                ¡é  |
      +----+--------+         ¦­¦¢                      ¦¢  ¦­         +----------+--+              
      |     File    |         ¦­¦¢                      ¦¢  ¦­         |     File    |              
      +-------------+         ¦­¦¢                      ¦¢  ¦­         +-------------+              
           Disk               ¦­¦¢                      ¦¢  ¦­                   Disk             
                              ¦±¦»¦¬¦¬¦¬¦¬¦¬¦¬¦¬¦¬¦¬¦¬¦¬¦»¦¬¦°           
     ---------------------------¦ª----------------------¦ª---------------------------------




3. NFS(Network File System)
   * disk ¿µ¿ªÀ» °ü¸®ÇÏ°í fileÀÇ access¸¦ °ü¸®Çϱ⵵ ÇÏ´Â µîÀÇ ÀÏÀº OSÀÇ filesystemÀÌ ´ã´çÇÏ´ø °Í.
     ÀÌ¿Í °°ÀÌ filesystemÀÌ ÇÏ´ø ÀÛ¾÷À» networkÀ» ÃÊ¿ùÇؼ­ ¿©·¯´ëÀÇ ÄÄÇ»ÅÍ°¡ ½ÇÇàÇÒ ¼ö ÀÖ°Ô²û ÇÑ °ÍÀÌ
     ¹Ù·Î NFSÀÌ´Ù.
   * NFS´Â local file systemÀÌ ÀÖ´Â directory¿¡¼­ remote system»óÀÇ directory¿Í 
     ³í¸®ÀûÀ¸·Î ¿¬°á(mount)ÇÏ´Â ÀÛ¾÷À» ÇØÁØ´Ù.
     ÀÏ´Ü ±× Á¢¼Ó(mount)°¡ ÀÌ·ç¾îÁö¸é
     local disk¿Í ¸¶Âù°¡Áö·Î  remote disk¸¦ ÀüÇô Â÷ÀÌ ¾øÀÌ accessÇÒ ¼ö ÀÖ´Ù.
     »ç¿ëÀÚ³ª applicationÀº ÀÚ½ÅÀÌ accessÇÏ·Á´Â È­ÀÏÀÌ ½ÇÁ¦·Î ¾î´À ÄÄÇ»ÅÍ¿¡ ÀÖ´ÂÁö¸¦ ÀǽÄÇÒ ÇÊ¿ä°¡ ¾ø´Ù.  
   * NFS Á¢¼Ó ¹æ½ÄÀº local diskÀÇ filesystemÀÌ "UFS(4.2)" typeÀ¸·Î mountµÇµíÀÌ
     remote diskÀÇ filesystem or directory¸¦ "nfs" typeÀ¸·Î mountÇÏ¸é µÈ´Ù. 
   * NFS´Â server-client model·Î ±¸ÇöµÇ¸ç
     local disk¸¦ »ç¿ëÇÒ ¼ö ÀÖ°Ô²û Çã¿ëÇØ ÁÖ´Â ÂÊ, Áï exportÇØ ÁÖ´Â ÂÊÀ» "nfs server"¶ó ÇÏ°í
     remote disk¸¦ »ç¿ëÇÏ·Á ÇÏ´Â ÂÊ, Áï nfs mountÇÏ·Á´Â ÂÊÀ» "nfs client"¶ó ÇÑ´Ù.
   * NFS¸¦ »ç¿ëÇÏ¿© ¾òÀ» ¼ö ÀÖ´Â ÀÌÁ¡ Áß 'diskÀÇ Àý¾à'ÀÌ ÀÖ´Ù.
     ¿©·¯ ½Ã½ºÅÛ¿¡¼­ ¶È °°ÀÌ »ç¿ëÇÏ´Â fileµéÀ» °¢ ½Ã½ºÅÛ disk¸¶´Ù ÀúÀåÇØ ³õÁö ¾Ê°í
     ÇÑ ½Ã½ºÅÛ¿¡¸¸ ÀúÀåÇØ ³õ°í NFS mountÇØ »ç¿ëÇÏ¸é ±×¸¸Å­ disk¸¦ Àý¾àÇÒ ¼ö ÀְԵȴÙ. 
   * óÀ½¿¡´Â Sun workstationµéÀÌ disk¸¦ °øÀ¯Çϱâ À§ÇØ °³¹ßÇÏ¿´Áö¸¸
     ¿äÁîÀ½Àº ±âÁ¾¿¡ °ü°è¾øÀÌ ¶Ç ¿©·¯ OS¿¡ ±¸ÇöµÇµµ·Ï ¼³°èµÇ¾î ÀÖ´Ù.
     ¸¹Àº vendorµéÀÌ ±×µéÀÇ ÄÄÇ»ÅÍ¿¡ ´ëÇØ NFS¸¦ Á¦°øÇÏ°í ÀÖ´Ù.
     ÀÌó·³ ¹Î°£ ±â¾÷ÀÌ µ¶ÀÚÀû »ç¾çÀ» °áÁ¤ÇÑ °ÍÀÌ ¾÷°è¿¡ ³Î¸® ¼ö¿ëµÇ¸é¼­ »ç½Ç»óÀÇ Ç¥ÁØÀÌ µÈ °æ¿ì¸¦
     "defact standard(¾÷°èÇ¥ÁØ)"À̶ó ºÎ¸£°í
     IEEE µî °ø°ø±â°ü¿¡¼­ ±ÔÁ¤µÈ "IS(International Standard:±¹Á¦Ç¥ÁØ)"°ú´Â ±¸º°µÈ´Ù.

4. NFSÀÇ Software ±¸¼º

              Client                                           Server

       +-----------------------+
       |  Application Program  |   "remote file °ü¸®ºÎ¿¡ ÇØ´ç"
       +-----------------------+     ¦­
                    ¡é               ¦­
              +---------+  ¦¬¦¬¦¬¦¬¦¬¦´                                    +-----------+
      ¦£¦¡¦¡¦¡|  vnode  |¦¡¦¡¦¡¦¡¦¤  ¦­ "nework °ü¸®ºÎ¿¡ ÇØ´ç" ¦£¦¡¦¡¦¡¦¡¡æ|   vnode   |
      ¦¢      +---------+        ¦¢  ¦­ ¦­                     ¦¢          +-----------+
      ¡é            ¡é           ¡é  ¦­ ¦­                     ¦¢                ¡é
   +----------+ +---------+ +----------+¦­              +-------------+    +-----------+
   |  4.2 BSD | |   VFS   | |  Remote  |¦­              |  NFS server |    |  4.2 BSD  |
   |    VFS   | +---------+ |   VFS    |¦­              +-------------+    |    VFS    |
   +----------+     ¦¢      +----------+¦­                     ¡è          +-----------+
                    ¡é           ¡é     ¦­                     ¦¢                ¡é
                +---------+ +----------+¦­              +-------------+    +-----------+
                |  File   | | RPC/XDR  |¦°              |  RPC / XDR  |    |    File   |
                +---------+ +----------+                +-------------+    +-----------+
                                 ¦¢                            ¡è
                                 ¡é                            ¦¢
                            +----------+                +-------------+
                            |  TCP/IP  |                |  TCP / IP   |
                            +----------+                +-------------+
    LAN                          ¦¢                            ¦¢
     ¦¡¦¡¦¡¦¡¦¡¦¡¦¡¦¡¦¡¦¡¦¡¦¡¦¡¦¡¦ª¦¡¦¡¦¡¦¡¦¡¦¡¦¡¦¡¦¡¦¡¦¡¦¡¦¡¦¡¦ª¦¡¦¡¦¡¦¡¦¡¦¡¦¡¦¡¦¡¦¡¦¡¦¡¦¡


   VFS: Virtual File System             vnode : vitual node
   RPC: Remote Procedure Call           
   XDR: External Data Representation





Revision History
Created        on Jan. 22 ,1993