


NSR(8)                                                     NSR(8)


NNAAMMEE
       NSR - introduction and overview of NetWorker

DDEESSCCRRIIPPTTIIOONN
       NetWorker  facilitates the backup and recovery of files on
       a network of computer systems.  Files and filesystems  may
       be  backed  up  on  a scheduled basis.  Recovery of entire
       filesystems and single files is simplified by  use  of  an
       on-line index of saved files.

       NetWorker  uses  a client-server model to provide the file
       backup and recover service.  At least one machine  on  the
       network  is  designated  as  the NetWorker _s_e_r_v_e_r, and the
       machines with disks to be backed up are NetWorker _c_l_i_e_n_t_s.
       Five daemons provide the NetWorker service, control access
       to the system, and provide index and  media  support.   On
       the clients, there are special programs to access the file
       systems and communicate with the NetWorker server.

       The NetWorker system  has  several  parts.   Commands  and
       files are only briefly mentioned here; see the appropriate
       reference manual page for more detailed information.  Each
       command  has  a manual page entry in section 8.  The files
       and their formats are explained in section 5 manual pages.

       The Legato NetWorker Administrator's Guide provides infor-
       mation on configuring and administering a  NetWorker  sys-
       tem.  It includes many examples and rationales for setting
       up and running a successful backup operation.

IINNSSTTAALLLLAATTIIOONN
       How NetWorker is installed varies depending on the  archi-
       tecture  of the machine upon which you're installing.  See
       the Legato NetWorker Administrator's  Guide  for  detailed
       installation instructions.

       nnssrr__iizzee(8)    The   NetWorker  installation  script.   The
                     script  will  install   both   clients   and
                     servers.   The  nnssrr__iizzee  script  can also be
                     used to  de-install  NetWorker.   Note  that
                     some   systems   use   other   methods   for
                     installing and de-installing  NetWorker,  in
                     which  case  the  nnssrr__iizzee  script  will  not
                     exist.

       nnssrr__llaayyoouutt(5) Describes where NetWorker  programs,  files,
                     and manual pages are installed.

SSEERRVVEERR DDAAEEMMOONNSS
       NetWorker  uses  a client-server model to provide a backup
       and recover service.  The following daemons encompass  the
       server side of NetWorker.

       nnssrrdd(8)      The  main  NetWorker  daemon.   nnssrrdd  handles



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NSR(8)                                                     NSR(8)


                    initial  communication  with   clients,   and
                    starts  and  stops the other NetWorker server
                    daemons.

       aannssrrdd(8)     The _a_g_e_n_t nsrd process, spawned  by  nnssrrdd  in
                    response  to a recovery, clone, or other ses-
                    sion.  The aannssrrdd daemon is invoked on an  as-
                    needed  basis  and is only present when there
                    are sessions active to the NetWorker  server.
                    Modern versions of ssaavvee(8) do not require use
                    of an aannssrrdd daemon.

       nnssrriinnddeexxdd(8) This server daemon  provides  access  to  the
                    NetWorker  on-line  index.   The  index holds
                    records of saved  files.   The  index  allows
                    clients  to  selectively  browse  and  choose
                    files to recover without having to access the
                    backup media.

       nnssrrmmmmddbbdd(8)  The media management database daemon provides
                    an index of save sets and media.   The  nnssrrmm--
                    mmddbbdd  daemon  provides a much coarser view of
                    the saved  files  than  does  nnssrriinnddeexxdd,  and
                    therefore the resultant index is usually much
                    smaller.

       nnssrrmmmmdd(8)    The media multiplexor daemon provides  device
                    support  for  NetWorker.   When more than one
                    client is saving files, the  data  from  each
                    client is multiplexed.  During recovery oper-
                    ations, the data is  demultiplexed  and  sent
                    back  to  the  requesting  clients.  When the
                    multiple  devices  are  enabled,  several  of
                    these daemons may be active simultaneously.

AADDMMIINNIISSTTRRAATTIIOONN
       NetWorker  is  administered  via _r_e_s_o_u_r_c_e_s and _a_t_t_r_i_b_u_t_e_s.
       Every resource has one or more attributes associated  with
       it.   For  example, a device is a NetWorker resource type;
       an attribute of devices is the device _t_y_p_e,  for  example,
       4mm  or  8mm.  The NetWorker resource format is documented
       in nnssrr__rreessoouurrccee(5).  There is also a manual page for  each
       NetWorker resource in section 5 of the manual.

       Resource files are not normally edited by hand.  Rather, a
       NetWorker tool (usually nnwwaaddmmiinn(8) or nnssrraaddmmiinn(8)) is used
       to modify resource files dynamically so that values can be
       checked and changes can be propagated automatically to the
       interested programs.

       nnwwaaddmmiinn(8)   Monitors the activity of and administers Net-
                    Worker servers.  The nnwwaaddmmiinn command is an  X
                    Window System application, using a Motif look
                    and feel.  The nnwwaaddmmiinn command is most users'



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NSR(8)                                                     NSR(8)


                    primary interface to NetWorker.

       nnssrraaddmmiinn(8)  A ccuurrsseess(3) based tool for the administration
                    of NetWorker servers.

       nnssrrwwaattcchh(8)  A ccuurrsseess(3) based tool to monitor the  activ-
                    ity of NetWorker servers.

       nnssrrmmmm(8)     Media  manager command.  The nnssrrmmmm command is
                    used to label,  mount,  unmount,  delete  and
                    purge  volumes.  Mount requests are generated
                    by nnssrrmmmmdd, and displayed by nnwwaaddmmiinn  or  nnssrr--
                    wwaattcchh.   The  size  of  the on-line user file
                    indexes may be  controlled  by  deleting  and
                    purging volumes.

       nnssrrjjbb(8)     NetWorker's    jukebox-controlling   command.
                    When dealing with a  jukebox,  nnssrrjjbb,  rather
                    than  nnssrrmmmm,  should  be used to label, load,
                    and unload the  volumes  contained  within  a
                    jukebox.

       nnssrriimm(8)     Automatically   manages  the  on-line  index.
                    Usually run periodically by ssaavveeggrrpp.

       mmmmiinnffoo(8)    Provides information about volumes  and  save
                    sets.

       nnssrrcckk(8)     Checks  and  repairs  the  NetWorker  on-line
                    index.  It is  run  automatically  when  nnssrrdd
                    starts  up  if  the databases were not closed
                    cleanly due to a system crash.

       nnssrr__sshhuuttddoowwnn(8)
                    A shell script used to safely shut  down  the
                    local  NetWorker  server.   The  nnssrr__sshhuuttddoowwnn
                    script can only be run by the super user.

SSAAVVIINNGG FFIILLEESS
       NetWorker supports both scheduled  and  manual  saving  of
       files  and  filesystems.   Each client may be scheduled to
       save all or part of its  filesystems.   Different  clients
       may be scheduled to begin saving at different times.

       ssaavvee(8)      A  command-line-based  tool used to back up a
                    specified file or group of files.   The  ssaavvee
                    command  may  be  run  manually  by users and
                    administrators, or automatically by  ssaavveeggrrpp.

       nnwwbbaacckkuupp(8)  A Motif-based tool for backing up files.  The
                    nnwwbbaacckkuupp command is the graphical  equivalent
                    of ssaavvee.

       ssaavveeggrrpp(8)   Used  to  initiate  the  backup of a group of



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NSR(8)                                                     NSR(8)


                    client machines.  Usually  started  automati-
                    cally  by  the NetWorker server.  The ssaavveeggrrpp
                    command also backs up  the  clients'  on-line
                    file indexes, which are stored on the server.
                    When backing up the server  itself,  a  _b_o_o_t_-
                    _s_t_r_a_p save set is also created.

       nnssrreexxeecc(8)   The  _a_g_e_n_t  savegrp process, spawned by ssaavvee--
                    ggrrpp.   The  nnssrreexxeecc  command   monitors   the
                    progress of NetWorker commands.

       nnssrrcclloonnee(8)  The  NetWorker  save  set/volume cloning com-
                    mand.   Using  nnssrrcclloonnee,  _c_l_o_n_e_s,  or   exact
                    replicas,  of save sets or entire volumes can
                    be made.   Clone  data  is  indistinguishable
                    from  the  original data, except for the Net-
                    Worker media  volumes  upon  which  the  data
                    reside.

       nnssrreexxeeccdd(8)  NetWorker-specific  remote  execution service
                    which runs on  NetWorker  clients.   Used  by
                    ssaavveeggrrpp  to  start  ssaavvee and ssaavveeffss on client
                    machines.

       ssaavveeffss(8)    Used by ssaavveeggrrpp to determine  characteristics
                    of a client, and to map the save set _A_l_l to a
                    the current  list  of  all  save  sets  on  a
                    client.

RREECCOOVVEERRIINNGG FFIILLEESS
       NetWorker  maintains  an  on-line index of user files that
       have been saved.  Users may browse the  index  and  select
       files  for recovery.  This information is used to build an
       representation of the file heirarchy as of any time in the
       past.   NetWorker  then  locates  the  correct  volume and
       recovers the requested files.

       rreeccoovveerr(8)   Browses  the  on-line  user  file  index  and
                    selects files and filesystems to recover.

       nnwwrreeccoovveerr(8) A Motif-based tool for recovering files.  The
                    nnwwrreeccoovveerr command is the graphical equivalent
                    of rreeccoovveerr.

       mmmmrreeccoovv(8)   Used  only  for  disaster recovery.  Recovers
                    the special _b_o_o_t_s_t_r_a_p index and the  server's
                    on-line file index.  The rreeccoovveerr or nnwwrreeccoovveerr
                    commands are used to  recover  other  on-line
                    file indexes.

       ssccaannnneerr(8)   Verifies  correctness  and  integrity of Net-
                    Worker volumes.  Can  also  recover  complete
                    save  sets  and  rebuild the on-line file and
                    media indexes.



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NSR(8)                                                     NSR(8)


       nnssrr__ccrraasshh(8) A man page describing  crash  recovery  tech-
                    niques.

       nnssrriinnffoo(8)   Used  to  generate reports about the contents
                    of a client's file index.

AAPPPPLLIICCAATTIIOONN SSPPEECCIIFFIICC MMOODDUULLEESS
       In order to process user files in an optimal manner,  Net-
       Worker  provides  the  ASM mechanism.  Pattern matching is
       used to select files for processing by the different ASMs.
       The  patterns and associated ASMs are described in nnssrr(5).
       The ssaavvee command keeps track of which ASMs  were  used  to
       process  a  file  so that rreeccoovveerr may use the same ASMs to
       recover the file.

       uuaassmm(8)        UNIX filesystem specific save/recover  mod-
                      ule.   The uuaassmm man page documents the gen-
                      eral rules for all ASMs.  The uuaassmm  command
                      and  its man page actually comprise several
                      additional    ASMincluding     ccoommpprreessssaassmm,
                      mmaaiillaassmm, and xxllaatteeaassmm, to name a few.

       nnssrriinnddeexxaassmm(8) Processes the on-line user file indexes.

       nnssrrmmmmddbbaassmm(8)  Processes the on on-line media database.

SSEERRVVEERR LLOOCCAATTIIOONN
       On  large  networks there may be several NetWorker servers
       installed.  Each NetWorker client command  must  select  a
       server to use.

       For  server  selection, the client commands are classified
       into two groups: _a_d_m_i_n_i_s_t_r_a_t_i_o_n and _o_p_e_r_a_t_i_o_n.  The admin-
       istration  commands include nnwwaaddmmiinn, nnssrrwwaattcchh, and mmmmiinnffoo.
       The operation commands include ssaavvee, ssaavveeffss, and  rreeccoovveerr.
       Both  groups  of  commands  accept  a  --ss _s_e_r_v_e_r option to
       explicitly specify a NetWorker server.

       When a server is not explicitly specified,  the  operation
       commands use the following steps to locate one.  The first
       server found is used.

       1)   The machine where the current directory  is  actually
            located  is  determined.   This will either be an NFS
            server or the local machine.  If that  machine  is  a
            client  of  a NetWorker server as determined by a RAP
            query, then that NetWorker server is used.  Some com-
            mands  will actually do a broadcast RAP query to find
            a server; broadcasts can take up to a minute to  per-
            form.   If  more than one server backs up the current
            directory, one server will be picked, and an informa-
            tional  message  will  be  printed  showing the other
            server's names.




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NSR(8)                                                     NSR(8)


       2)   The machine where the current directory  is  actually
            located  is  examined  to  see  if  it is a NetWorker
            server.  If it is, then it is used.

       3)   The local machine is examined to see if it is a  Net-
            Worker server.  If it is, then it is used.

       4)   If  a NetWorker server has still not been found, then
            the machine with the hostname ``nsrhost'' is used.

       The administrative commands start with step number 3,  and
       follow  it with steps 1, 2 and finally 4.  When either set
       of commands fail to find a NetWorker server, an error mes-
       sage  is printed.  The nnssrraaddmmiinn command will use the local
       machine if it is a server, or the host named  ``nsrhost''.
       The  nnssrrmmmm  command  always  uses the local server, unless
       given the --ss _s_e_r_v_e_r  option.   Some  commands  now  use  a
       broadcast to locate servers.

       When there is only one NetWorker server on the network, or
       to designate a ``primary'' server, add a ``nsrhost'' alias
       for the appropriate machine to your host table.  For exam-
       ple, edit the file ``/etc/hosts'' if you are using a  file
       for your host table.  When running the Network Information
       System (NIS, formerly called Yellow Pages or YP), add  the
       ``nsrhost''  alias  on  the  master and push the ``hosts''
       map.   Otherwise,  add  the  ``nsrhost''  alias   to   the
       /etc/hosts  file  for  every  client  and the server.  See
       yyppffiilleess(5) and yyppmmaakkee(8).

SSEECCUURRIITTYY
       Before a save is allowed, there  must  be  an  NNSSRR  cclliieenntt
       resource  created for the given client.  Before a recovery
       is allowed, the server validates client access by checking
       the  rreemmoottee  aacccceessss  attribute  in the NNSSRR cclliieenntt resource
       (see nnssrr__cclliieenntt(5)).  Earlier versions NetWorker  required
       that  connections  come  to  the server using ports in the
       reserved port range.  This required UNIX clients to be run
       with  an  effective uid of root at connection set up time.
       Newer versions of NetWorker use a stronger RPC authentica-
       tion  flavor and do not depend on using reserved ports and
       so setuid root operation is not required.

       The ssaavveeggrrpp(8) command initiates the  ssaavvee(8)  command  on
       each  client  machine  in an NSR group by using the nnssrreexx--
       eeccdd(8) remote save execution service.  See the nnssrreexxeeccdd(8)
       man  page  for  details.   For backward compatibility with
       older versions of NetWorker, ssaavveeggrrpp(8) will fall back  on
       using the rrsshh(1) protocol for remote execution if nnssrreexxeeccdd
       is not running on a particular client.

       Access to the NSR resources  through  the  nnssrraaddmmiinn(8)  or
       nnwwaaddmmiinn(8)  commands  is  controlled  by the aaddmmiinniissttrraattoorr
       attribute on each resource.  This attribute has a list  of



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NSR(8)                                                     NSR(8)


       names  of the users who have permission to administer that
       resource.  Names that begin with an ampersand  (&)  denote
       netgroups  (see  nneettggrroouupp(5)).   Also  names can be of the
       form _u_s_e_r@@_h_o_s_t to authorize a specific user on a  specific
       host.

NNAAMMIINNGG AANNDD AAUUTTHHEENNTTIICCAATTIIOONN
       As  described  above,  the NSR server only accepts connec-
       tions initiated from the machines  listed  as  clients  or
       listed  in the rreemmoottee aacccceessss list (for recovering).  Since
       machines may be connected to more than one  physical  net-
       work  and  since each physical network connection may have
       numerous aliases, the policies below are used as a compro-
       mise between security and ease of use.  For further infor-
       mation about naming in  the  UNIX  environment,  refer  to
       ggeetthhoosstteenntt(3), or other documentation on name services.

       A  client  determines  its own name as follows.  First the
       client's UNIX system name is  acquired  via  the  ggeetthhoosstt--
       nnaammee(2)  system  call.   The UNIX system name is used as a
       parameter to the ggeetthhoossttbbyynnaammee(3)  library  routine.   The
       client  declares  its  name  to be the official (or ``pri-
       mary'') name returned  by  ggeetthhoossttbbyynnaammee.   This  name  is
       passed  to  the  NetWorker server during connection estab-
       lishment.

       A server authenticates a client connection by  reconciling
       the connection's remote address with client's stated name.
       The address is mapped to a list  of  host  names  via  the
       ggeetthhoossttbbyyaaddddrr(3)  library  function.   Next,  the client's
       stated name is used as a  parameter  to  ggeetthhoossttbbyynnaammee  to
       acquire  another  list  of host names.  The client is suc-
       cessfully authenticated if and only if there exists a com-
       mon name between the two lists.

       The  NetWorker  server  maps a client's name to an on-line
       index database name by resolving the client's name to  the
       official  name  returned  by  ggeetthhoossttbbyynnaammee.  This mapping
       takes place both at client creation time and at connection
       establishment time.

       To  ensure  safe and effective naming, the following rules
       should be employed:

       1)   The NetWorker clients and servers should access  con-
            sistent host name databases.  NIS (YP) and the Domain
            Name System (DNS) are naming subsystems that  aid  in
            host name consistency.

       2)   All hosts entries for a single machine should have at
            least one common alias among them.

       3)   When creating a new client, use a name or alias  that
            will  map  back  to  the  same official name that the



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NSR(8)                                                     NSR(8)


            client machine produces by backward mapping its  UNIX
            system name.

SSEEEE AALLSSOO
       rrsshh(1), ggeetthhoossttnnaammee(2), ggeetthhoosstteenntt(3), nneettggrroouupp(5),
       nnssrr(5), nnssrr__llaayyoouutt(5), nnssrr__rreessoouurrccee(5), yyppffiilleess(5),
       yyppmmaakkee(5), mmmmiinnffoo(8), nnssrr__ccrraasshh(8), nnssrr__iizzee(8),
       nnssrr__sshhuuttddoowwnn(8), nnssrraaddmmiinn(8), nnssrrcckk(8), nnssrrcclloonnee(8),
       nnssrrdd(8), nnssrreexxeeccdd(8), nnssrriimm(8), nnssrriinnddeexxaassmm(8),
       nnssrriinnddeexxdd(8), nnssrriinnffoo(8), nnssrrjjbb(8), nnssrrllss(8), nnssrrmmmm(8),
       nnssrrmmmmdd(8), nnssrrmmmmddbbaassmm(8), nnssrrmmmmddbbdd(8), nnssrrwwaattcchh(8),
       nnwwaaddmmiinn(8), nnwwbbaacckkuupp(8), nnwwrreeccoovveerr(8), rreeccoovveerr(8),
       mmmmrreeccoovv(8), ssaavvee(8), ssaavveeffss(8), ssaavveeggrrpp(8), ssccaannnneerr(8),
       uuaassmm(8).
       The Legato NetWorker Administrator's Guide










































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