X-Git-Url: http://git.alex.org.uk diff --git a/man/nbd-server.5.in.sgml b/man/nbd-server.5.in.sgml index 9fb2eff..1bc1980 100644 --- a/man/nbd-server.5.in.sgml +++ b/man/nbd-server.5.in.sgml @@ -287,6 +287,39 @@ manpage.1: manpage.sgml + + + Optional; boolean. + When this option is enabled, + nbd-server will inform the client that it + supports and desires to be sent flush requests when the + elevator layer receives them. Receipt of a flush request + will cause an fdatasync() (or, if the sync option is set, + an fsync()) on the backend storage. This increases + reliability in the case of an unclean shutdown at + the expense of a degradation of performance. This option + will have no effect unless supported by the client. + + + + + + + Optional; boolean. + When this option is enabled, + nbd-server will inform the client that it + supports and desires to be sent fua (force unit access) commands + when the elevator layer receives them. Receipt of a force unit + access command will cause the specified command to be synced + to backend storage using sync_file_range() if supported, or + fdatasync() otherwise. This increases + reliability in the case of an unclean shutdown at + the expense of a degradation of performance. This option + will have no effect unless supported by the client. + + + + listenaddr @@ -301,6 +334,16 @@ manpage.1: manpage.sgml + + + Optional; integer + + If specified, then it limits the number of opened connections for + this export. + + + + Optional; boolean. @@ -354,6 +397,53 @@ manpage.1: manpage.sgml + + + Optional; string + + If specified, then it is assumed to be a command + that will be ran when a client has + disconnected. This can be useful to clean up + whatever has set up, to log + something, or similar. + + + If the literal string '%s' is present in the + command, it will be replaced by the file name that + has just been closed. + + + In contrast to the option, + the exit state of is + ignored. + + + + + + + Optional; string + + If specified, then this command will be ran after a + client has connected to the server (and has been + accepted), but before the server starts serving. If + the command contains the literal string '%s', then + this string will be replaced by the filename of the + file which nbd-server wants to export. + + + This is useful to create export files on the fly, or + to verify that a file can be used for export, to + write something to a log file, or similar. + + + If the command runs with a non-zero exit status, + then nbd-server will assume the export will fail, + and refuse to serve it. + + + + Optional; boolean. @@ -371,6 +461,29 @@ manpage.1: manpage.sgml + + + Optional; boolean. + When this option is enabled, + nbd-server will inform the client that + it would prefer it to send requests in elevator (i.e., optimized) order, perhaps + because it has a backing store and no local elevator. By + default, the client uses QUEUE_FLAG_NONROT, which effectively + restricts the function of the elevator to block merges. By + specifying this flag on the server, the client will not use + QUEUE_FLAG_NONROT, meaning the client elevator will perform + normal elevator ordering of I/O requests. Note that even when + the backing store is on rotating media, it is not normally + necessary to specify this flag, as the server's elevator + algorithm will be used. This flag is only required where + the server will not be using an elevator algorithm or where + the elevator algorithm is effectively neutered (e.g. with + the sync option set). This option will have no effect unless + supported by the client. + + + + Optional; boolean. @@ -393,23 +506,6 @@ manpage.1: manpage.sgml - - - Optional; boolean. - When this option is enabled, - nbd-server will call an fsync() after every - write to the backend storage. Calling fsync() increases - reliability in case of an unclean shutdown of nbd-server; but, - depending on the file system used on the nbd-server side, may - degrade performance. The use of this option isn't always - necessary; e.g., on ext3 filesystems, it is recommended that - it is not enabled, since it seriously - reduces performance on ext3 filesystems while not - importantly impacting reliability. - - - - Optional; boolean. @@ -435,6 +531,23 @@ manpage.1: manpage.sgml + + + Optional; boolean. + When this option is enabled, + nbd-server will call an fsync() after every + write to the backend storage. Calling fsync() increases + reliability in case of an unclean shutdown of nbd-server; but, + depending on the file system used on the nbd-server side, may + degrade performance. The use of this option isn't always + necessary; e.g., on ext3 filesystems, it is recommended that + it is not enabled, since it seriously + reduces performance on ext3 filesystems while not + importantly impacting reliability. + + + + Optional; integer; default 0 @@ -452,6 +565,30 @@ manpage.1: manpage.sgml + + + Optional; string + + If specified, then this pathname is used to generate a transaction + log. A transaction log is a binary file consisting of the requests + sent to and the replies received by the server, but excluding any + data (so, for a write command, it records the offset and length + of the write but not the data written). It is therefore relatively + safe to distribute to a third party. Note that the transaction log + does not include the negotiation sequence. Transaction logs are + mainly useful for debugging. The program + nbd-tester-client distributed with the source + to this program can reply a transaction log against a server and + perform a data integrity test. Note that the transaction log is + written to for every client opened. If it is necessary to maintain + separate transaction logs for each client, the + prerun script should rename the transaction log + (which will just have been opened in order to avoid transaction logs + overwriting eachother. This action should be race-free. + + + + Optional; string; default "ipliteral" @@ -548,70 +685,13 @@ manpage.1: manpage.sgml - - - - Optional; string - - If specified, then this command will be ran after a - client has connected to the server (and has been - accepted), but before the server starts serving. If - the command contains the literal string '%s', then - this string will be replaced by the filename of the - file which nbd-server wants to export. - - - This is useful to create export files on the fly, or - to verify that a file can be used for export, to - write something to a log file, or similar. - - - If the command runs with a non-zero exit status, - then nbd-server will assume the export will fail, - and refuse to serve it. - - - - - - - Optional; string - - If specified, then it is assumed to be a command - that will be ran when a client has - disconnected. This can be useful to clean up - whatever has set up, to log - something, or similar. - - - If the literal string '%s' is present in the - command, it will be replaced by the file name that - has just been closed. - - - In contrast to the option, - the exit state of is - ignored. - - - - - - - Optional; integer - - If specified, then it limits the number of opened connections for - this export. - - - SEE ALSO - nbd-server (1), nbd-client (8) + nbd-server (1), nbd-client (8), nbd-trdump (8)