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NAME |
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Linux::NBD::Client - client (device) side of a network block device |
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SYNOPSIS |
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use Linux::NBD::Client; |
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DESCRIPTION |
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WARNING: I talked to the author of the nbd driver because nbd is so |
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extremely racy (right now, stopping it often causes oopses, a server |
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crashing also often oopses etc..). |
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It turned out that he doesn't care at all and nbd is basically |
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unmaintained, so YMMV when using this module, especially when writing |
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servers. |
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He really should have said that on his nbd pages ;[. |
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OTOH, it works relatively reliable when you don't stop the servers, so |
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watch out and keep your fingers crossed. |
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METHODS |
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$client = new Linux::NBD::Client [socket => $fh][, device => |
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"/dev/ndx"], ... |
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Create a new client. |
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Unless "device" is given, an unused device node is looked up using |
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the "device" method (this might result in an exception!). |
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The other arguments correspond to calls to methods of the same name. |
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$client->socket([$tcp_socket]) |
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Returns the current socket after setting a new one (if an argument |
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is supplied). The socket *MUST* be a tcp socket. Believe, bad things |
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will happen. |
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The special argument "undef" will try to clear the socket, if any |
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was set. |
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$client->device([$new_device]) |
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Returns the current device node (e.g. "/dev/nd2") after setting a |
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new one if an argument is supplied. |
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If the argument is "undef" it will search for an unallocated |
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nbd-device and use it. |
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$client->disconnect |
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Tries to exit the server by ending a special disconnect message. |
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$client->clear_queue |
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Clears the request queue, if possible. Should be used before setting |
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a new socket. |
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$client->set_blocksize($blksize) |
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Set the device blocksize in bytes (must be >512, <PAGESIZE and a |
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power of two). |
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$client->set_size($bytes) |
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Set the device size in bytes. |
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$client->set_blocks($nblocks) |
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Set the size in blocks. |
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$client->run |
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Enters the service loop (waits for read/write requests on the device |
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and forwards them over the given socket). Only returns when somebody |
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calls "disconnect" or the server is killed. |
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$pid = $client->run_async |
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Runs the service loop asynchronously and returns the pid of the |
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newly created service process. |
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$client->kill_async |
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Kills any running async service. Please note that this also kills |
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the socket, so you need to re-set the socket after this call. |
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AUTHOR |
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Marc Lehmann <schmorp@schmorp.de> |
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http://home.schmorp.de/ |
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