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1 | NAME |
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2 | Linux::NBD::Client - client (device) side of a network blokc device |
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3 | |
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4 | SYNOPSIS |
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5 | use Linux::NBD::Client; |
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6 | |
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7 | DESCRIPTION |
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8 | WARNING: I talked to the author of the nbd driver because nbd is so |
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9 | extremely racy (right now, stopping it often causes oopses, a server |
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10 | crashing also often oopses etc..). |
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11 | |
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12 | It turned out that he doesn't care at all and nbd is basically |
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13 | unmaintained, so YMMV when using this module, especially when writing |
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14 | servers. |
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15 | |
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16 | He really should have said that on his nbd pages ;[. |
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17 | |
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18 | OTOH, it works relatively reliable when you don't stop the servers, so |
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19 | watch out and keep your fingers crossed. |
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20 | |
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21 | METHODS |
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22 | $client = new Linux::NBD::Client [socket => $fh][, device => |
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23 | "/dev/ndx"], ... |
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24 | Create a new client. |
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25 | |
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26 | Unless "device" is given, an unused device node is looked up using |
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27 | the "device" method (this might result in an exception!). |
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28 | |
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29 | The other arguments correspond to calls to methods of the same name. |
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30 | |
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31 | $client->socket([$tcp_socket]) |
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32 | Returns the current socket after setting a new one (if an argument |
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33 | is supplied). The socket *MUST* be a tcp socket. Believe, bad things |
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34 | will happen. |
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35 | |
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36 | The special argument "undef" will try to clear the socket, if any |
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37 | was set. |
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38 | |
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39 | $client->device([$new_device]) |
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40 | Returns the current device node (e.g. "/dev/nd2") after setting a |
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41 | new one if an argument is supplied. |
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42 | |
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43 | If the argument is "undef" it will search for an unallocated |
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44 | nbd-device and use it. |
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45 | |
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46 | $client->disconnect |
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47 | Tries to exit the server by ending a special disconnect message. |
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48 | |
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49 | $client->clear_queue |
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50 | Clears the request queue, if possible. Should be used before setting |
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51 | a new socket. |
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52 | |
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53 | $client->set_blocksize($blksize) |
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54 | Set the device blocksize in bytes (must be >512, <PAGESIZE and a |
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55 | power of two). |
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56 | |
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57 | $client->set_size($bytes) |
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58 | Set the device size in bytes. |
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59 | |
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60 | $client->set_blocks($nblocks) |
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61 | Set the size in blocks. |
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62 | |
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63 | $client->run |
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64 | Enters the service loop (waits for read/write requests on the device |
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65 | and forwards them over the given socket). Only returns when somebody |
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66 | calls "disconnect" or the server is killed. |
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67 | |
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68 | $pid = $client->run_async |
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69 | Runs the service loop asynchronously and returns the pid of the |
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70 | newly created service process. |
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71 | |
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72 | $client->kill_async |
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73 | Kills any running async service. Please note that this also kills |
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74 | the socket, so you need to re-set the socket after this call. |
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75 | |
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76 | AUTHOR |
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77 | Marc Lehmann <schmorp@schmorp.de> |
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78 | http://home.schmorp.de/ |
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79 | |