NFS-Root Mini-Howto
  Andreas Kostyrka, andreas@ag.or.at
  V8, 8 Aygoustoy 1997

  Ayto to mini-HOWTO prospa8ei na ejhghsei pws na sthsoyme enan Linux
  workstation (ws) xwris diskoys-disketes (diskless), poy kanei mount ta
  root filesystems toy mesw toy NFS.  Ka8e newterh ekdosh aytou toy
  mini-Howto 8a brisketai panta sto ftp://sun-
  site.unc.edu/pub/Linux/docs/HOWTO/mini/NFS-Root , h ston plhsiestero
  se sas mirror toy SunSite.
  ______________________________________________________________________

  Table of Contents


  1. Copyright

     1.1 Poioi syneiseferan

  2. Genikh 8ewrhsh

  3. Ry8miseis ston server

     3.1 Kanontas compile stoys pyrhnes
     3.2 Dhmioyrgia toy root filesystem
        3.2.1 Antigrafontas to filesystem
        3.2.2 Allages sto root filesystem
        3.2.3 Kanontas export to filesystem
        3.2.4 Ru8mish toy RARP
        3.2.5 Ru8mish toy BOOTP
        3.2.6 Briskontas tis hardware diey8unseis twn kartwn

  4. Bootarontas ton workstation

     4.1 Xrhsimopoiwntas mia boot eprom
     4.2 Xrhsimopoiwntas mia disketa sketoy pyrhna
     4.3 Xrhsimopoiwntas enan bootloader & to
     4.4 Xrhsimopoiwntas enan bootloader xwris to

  5. Gnwsta problhmata

     5.1 To /sbin/init den jekinaei.
     5.2 Problhmata me to /dev .

  6. Alla 8emata



  ______________________________________________________________________

  1.  Copyright

  (c) 1996 Andreas Kostyrka (e9207884@student.tuwien.ac.at , h
  andreas@ag.or.at)

  Ektos ki an ekfrastei diaforetika, ta keimena Linux HOWTO einai
  katoxyrwmena apo toys antistoixoys syggrafeis toys. Ta keimena ayta
  epitrepetai n' anaparax8oun kai na dianemh8oun oloklhra h kata merh,
  me opoiodhpote mhxaniko h hlektroniko meson, oso ayth edw h shmeiwsh
  gia to copyright diathreitai epanw se ka8e antigrafo. H emporikh
  dianomh epitrepetai kai en8arrunetai. Wstoso, o syggrafeas epi8ymei na
  eidopoieitai gia opoiadhpote tetoia dianomh.  Oles oi metafraseis,
  paragwges ergasies, h syllogikes ergasies poy perilambanoyn
  opoiodhpote keimeno Linux HOWTO, prepei na kaluptontai apo aythn edw
  th shmeiwsh peri copyright. Dhladh, den epitrepetai na paragete mia
  ergasia basismenh s' ena HOWTO, kai na epiballete epipros8etoys
  periorismous sth dianomh ths. Ejaireseis stoys parapanw oroys mporoun
  na epitrapoun ypo orismenes proupo8eseis. Parakaloume na er8ete s'
  epafh me ton syntonisth twn Linux HOWTO, sth dieu8ynsh poy yparxei
  parakatw.  Se syntomia : Epi8ymoume na prow8hsoyme tis plhrofories poy
  periexontai sthn ergasia ayth, me oso to dynaton perissotera mesa.
  Wstoso, epishs epi8ymoume na krathsoyme to copyright twn keimenwn
  HOWTO, kai 8a 8elame na eidopoioumaste gia opoiadhpote sxedia dianomhs
  twn HOWTOs.

  Ean exete apories, parakaloume na er8ete s' epafh me ton Andreas
  Kostyrka <mailto:andreas@ag.or.at>, ton syggrafea aytou edw toy mini-
  HOWTO, h ton Tim Bynum, ton syntonisth twn Linux HOWTO's, sth
  dieu8ynsh <mailto:linux-howto@sunsite.unc.edu> mesw email.


  1.1.  Poioi syneiseferan


  ·  Avery Pennarun <apenwarr@foxnet.net> (pws na bootaroyme xwris LILO)

  ·   Ofer Maor <ofer@hadar.co.il> (edwse ena kalutero mini howto epanw
     sto pws na sthnoyme diskless workstations.)

  ·  Christian Leutloff <leutloff@sundancer.tng.oche.de> (edwse
     plhrofories sxetikes me to netboot.)


  2.  Genikh 8ewrhsh

  Genika, yparxoyn ta parakatw problhmata gia enan ws :

  ·  Prepei na brei th dikh toy dieu8ynsh IP, kai - an xreiastei - tis
     ypoloipes ry8miseis toy Ethernet.

  ·  Prepei na gnwrizei to NFS-server kai to mount path gia to root
     filesystem toy.

  H twrinh ylopoihsh toy NFSROOT ston pyrhna toy Linux (ekdosh 1.3.7x)
  epitrepei tis akoloy8es luseis :

  ·  H dieu8ynsh IP mporei na bre8ei apo to RARP, h h plhrhs ru8mish toy
     Ethernet mporei na perastei ston pyrhna mesw parametrwn (toy
     pyrhna), apo to LILO , h to LOADLIN.

  ·  To mounting path toy NFS mporei na perastei me parametroys toy Ean
     den ginei etsi, o pyrhnas ypo8etei oti to RARP-server einai epishs
     NFS-server, kai xrhsimopoiei to default compiled mesa toy path.  (H
     trexoysa default timh ston pyrhna einai h : /tftpboot/<IP-dieu8ynsh
     toy HY>.)

  ·  Oi ry8miseis toy client aneyriskontai apo to BOOTP.

  Prin arxisete na sthnete ena diskless periballon, prepei n'
  apofasisete an 8a bootarete me to LILO , h to LOADLIN. To pleonekthma
  einai h eyelijia, to meionekthma einai h taxuthta. Einai taxutero na
  bootaroyme enan pyrhna toy Linux xwris to LILO , alla ayto mporei na
  mas apasxolhsei, mporei kai oxi.


  3.  Ry8miseis ston server

  3.1.  Kanontas compile stoys pyrhnes

  Pi8anotata h yposthrijh toy RARP mesa ston pyrhna toy server na einai
  mia kalh idea. Prepei na thn symperilabete, an einai na bootarete
  xwris parametroys pyrhna. Apo thn allh pleyra, den prokeitai na sas
  boh8hsei, an o client den brisketai sto idio ypodiktyo (subnet) me ton
  server.

  O pyrhnas gia ton ws xreiazetai to akoloy8o elaxisto sunolo
  dynatothtwn compiled mesa toy :

  ·  To NFS-filesystem . (Den xreiazetai na exei compiled mesa toy thn
     yposthrijh gia ext2 , ena module einai arketo.)

  ·  To "Root on NFS" prepei na einai energopoihmeno.

  ·  Ton Ethernet driver ths kartas diktuoy toy ws.

  ·  Analoga me tis anagkes sas, pi8anon na prepei na perilabete
     yposthrijh gia RARP , h BOOTBP gia to NFS-Root. (M' ayto ennow tis
     erwthseis poy kanoyme meta thn erwthsh gia to NFS sto make config.)

  An o ws 8a bootarei xwris parametroys toy pyrhna, prepei epishs na
  8esete to root device ws 0:255. Kante to ayto dhmioyrgwntas ena
  ceutiko (dummy) arxeio device, dinontas : mknod /dev/nfsroot b 0 255.
  Afou ftiajete ayto to arxeio, mporeite na 8esete to root device toy
  image toy pyrhna, me : rdev <kernel-image> /dev/nfsroot.

  3.2.  Dhmioyrgia toy root filesystem

  3.2.1.  Antigrafontas to filesystem

   Proeidopoihsh : An kai aytes edw oi odhgies pi8anotata 8a doylecoyn
  sto diko sas susthma, den einai ka8oloy aytonohtes gia opoiodhpote
  periballon. Gia kaluteroys tropoys na sthsete ena root filesystem gia
  toys clients, diabaste to NFS-Root-Client mini howto toy Ofer Maor
  <ofer@hadar.co.il>.

  Afou apofasisete pou 8a balete to root tree, dhmioyrghste to me (px) :
  mkdir -p <directory> kai : tar cClf / - | tar xpCf <directory> -.

  An bootarete ton pyrhna sas xwris LILO, tote to rootdir prepei na
  einai : /tftpboot/<IP-address>. An den sas aresei, mporeite na to
  allajete apo mesa apo to epanw-epanw Makefile sta sources toy pyrhna.
  Yajte gia mia grammh san ayth : NFS_ROOT =
  -DNFS_ROOT="\"/tftpboot/%s\"" An allajete ayth thn grammh, prepei na
  janakanete compile ton pyrhna.


  3.2.2.  Allages sto root filesystem

  Twra afaireste ta axrhsta arxeia, kai elegjte ta scripts toy /etc/rc.d
  .  Merika shmantika shmeia :

  ·  Ena, h ru8mish toy eth0. O ws synh8ws exei ena ry8mismeno
     (toylaxiston merikws) eth0. To na ry8misete th dieu8ynsh IP toy ws
     epanw sth dieu8ynsh IP toy server, den einai kati ejypno. (Alla
     synebh ston syggrafea kata th diarkeia mias apo tis prwimes
     prospa8eies toy.)

  ·  Ena allo shmeio prosoxhs, einai to /etc/fstab toy ws. Prepei na
     ry8mistei gia nfs filesystems.

  ·  PROEIDOPOIHSH : Mhn sygxeete ta root filesystems toy server kai toy
     ws. (Eixa hdh rijei ena rc.inet1 panw ston server, kai aporousa
     giati o server den douleye.)





  3.2.3.  Kanontas export to filesystem

  Kante export to root dir pros ton ws. Diabaste thn entolh :
  exports(5).  Pi8anotata 8a prepei na epanekkinhsete to nfsd/mountd
  meta ap' ayth thn allagh. Me to RedHat ayto ginetai eukola, dinontas :
  /etc/rc.d/init.d/nfs stop ; /etc/rc.d/init.d/nfs start .


  3.2.4.  Ru8mish toy RARP

  Ry8miste to RARP kapoy epanw sto diktyo. An bootarete xwris parametro
  nfsroot, o server toy RARP prepei na einai kai o server toy NFS .
  (Synh8ws einai.) Gia na to epituxete ayto, prepei na trejete enan
  pyrhna me yposthrijh RARP .

  Gia na to kanete, dwste (kai egkatasthste to kapoy mesa sto /etc/rc.d
  toy server!) :

  /sbin/rarp -s <ip-addr> <hardware-addr>

  opoy :

     ip-addr
        einai h dieu8ynsh IP toy ws, kai

     hardware-addr
        einai h dieu8ynsh Ethernet ths kartas diktuoy toy ws.

  paradeigma : /sbin/rarp -s 131.131.90.200 00:00:c0:47:10:12

  Mporeite epishs na xrhsimopoihsete ena symboliko onoma anti ths
  dieu8ynshs IP, oso o server einai ikanos na briskei th dieu8ynsh ayth.
  (Me cajimo sto /etc/hosts , h sto DNS .)


  3.2.5.  Ru8mish toy BOOTP

  Gia th ru8mish toy BOOTP prepei na dior8wsete to /etc/bootptab.
  Parakalw, symboyleyteite tis man selides bootpd(8) kai bootptab(5) .


  3.2.6.  Briskontas tis hardware diey8unseis twn kartwn

  Den jerw poia einai h hardware dieu8ynsh! Pws thn briskw;

  ·  Bootarete th disketa poy ftiajate, kai perimenete th grammh
     diagnwstikwn, opoy anagnwrizetai h karta diktuoy. Synh8ws periexei
     6 dekaejadika bytes, kai ayth (prepei na) einai h hardware
     dieu8ynsh ths kartas.

  ·  Bootarete ton ws me kapoio allo leitoyrgiko, poy perilambanei
     dynatothta TCP/IP . Tote kante ping ston ws apo ton server. Yajte
     sthn cache toy ARP, dinontas : /sbin/arp -a


  4.  Bootarontas ton workstation


  4.1.  Xrhsimopoiwntas mia boot eprom

  Mia poy proswpika den exw akomh xrhsimopoihsei ena tetoio 8hrio, mporw
  na sas dwsw monaxa tis akoloy8es ypodeijeis (xarh ston Christian
  Leutloff <leutloff@sundancer.tng.oche.de>) :

  ·  Den mporeite na xrhsimopoihsete "synh8ismenes" bootroms.

  ·  Yparxei ena programma netboot , apo ton Gero Kuhlmann, poy ftiaxnei
     bootroms gia Linux, kai dinei perissoteres plhrofories. To netboot
     einai dia8esimo apo ton plhsiestero mirror toy Linux, h san
     programma mesa sth distribution toy Debian (netboot-0.4).

  ·  Diabaste prosektika thn tekmhriwsh ths boot eprom sas.

  ·  Pi8anotata prepei na energopoihsete to tftpd ston server, alla ayto
     ejartatai apo ton tropo, me ton opoio h boot eprom sas fortwnei ton
     pyrhna.

  ·  Ka8e plhroforia gia pwlhtes boot eproms gia to Linux, opws tis
     perigracame parapanw, einai eyprosdekth - ka8ws den exei o ka8enas
     prosbash se eprom programmer :( (eidika sthn Eyrwph, opoy zw). Tis
     plhrofories 8a tis perilabw edw meta.

  4.2.  Xrhsimopoiwntas mia disketa sketoy pyrhna

  An exete kanei export to root filesystem me to swsto onoma gia thn
  default onomasia, kai o NFS server sas einai taytoxrona kai RARP
  server (poy shmainei oti oi HY briskontai sto idio ypodiktyo), tote
  mporeite apla na bootarete ton pyrhna me cating se mia disketa.
  (Prepei na 8esete to root device toy pyrhna ws 0:255.) Ayto
  proupo8etei oti to root directory ston server einai /tftpboot/IP-
  Address (ayth h timh mporei n' allajei, otan kanoyme compile ton
  pyrhna).

  4.3.  Xrhsimopoiwntas enan bootloader & to RARP

  Dwste ston pyrhna oles tis aparaithtes parametroys kata thn ekkinhsh,
  kai pros8este : nfsroot=<server-ip-addr>:</path/to/mount> , opoy :
  server-ip-addr einai h dieu8ynsh IP toy NFS-server sas, kai
  /path/to/mount einai to path pros to root directory.

  Ypodeijeis :

  ·  Otan xrhsimopoieite to LILO , skef8eite na xrhsimopoihsete thn
     idiothta "lock" : Apla plhktrologhste mia fora oles tis swstes
     parametroys, kai pros8este "lock" . Thn epomenh fora poy 8a
     bootarete, afhste to LILO na ftasei se timeout.

  ·  Otan ftiaxnete mia disketa gia enan sygkekrimeno ws, mporeite
     epishs na xrhsimopoihsete thn idiothta append= sto lilo.conf .

  4.4.  Xrhsimopoiwntas enan bootloader xwris to RARP

  Mazi me to nfsroot , dwste ena orisma pyrhna sth grammh entolwn :
  nfsaddrs=<wst-IP>:<srv-IP>:<gw-IP>:<netm-IP>:<hostname> .  O pyrhnas
  8a ry8misei to eth0 me tis dedomenes parametroys :

     wst-IP
        Dieu8ynsh IP toy HY

     srv-IP
        Dieu8ynsh IP toy NFS-server

     gw-IP
        gateway

     netm-IP
        netmask

     hostname
        onoma ypologisth


  5.  Gnwsta problhmata


  5.1.  To /sbin/init den jekinaei.

  Ena polu synh8ismeno problhma me to /sbin/init einai oti (toylaxiston)
  merikes apo tis prosfates distributions exoyn to /sbin/init linked
  dynamika. Synepws, prepei na dwsete swsth ru8mish /lib gia ton client.
  Kati eukolo poy mporoume na dokimasoyme, einai n' antikatasthsoyme to
  /sbin/init (toy client) me ena statika linked programma "Hello World".
  M' ayton ton tropo 8a jerete an prokeitai gia kati pio 8emeliwdes apo
  apla ena problhma me to dynamiko linking.

  5.2.  Problhmata me to /dev .

  An kata thn ekkinhsh pairnete kapoia mperdemena mhnumata gia ta ttys,
  tote 8a eprepe na trejete ena MAKEDEV apo ton client sto /dev
  directory.  Yparxoyn fhmes oti ayto den doyleuei me kapoia LS poy
  xrhsimopoioun 64-bit ari8mous dev. An sas tuxei kati tetoio, parakalw
  steilte moy e-mail gia poio LS prokeitai. Mia pi8anh lush einai na
  ftiajete nwris sth diadikasia ekkinhshs ena mikro /dev ramdisc, kai na
  epanegka8istate ta device nodes ka8e fora.


  6.  Alla 8emata


  ·  Yparxei ena BOOTP programma :
     ftp://sunsite.unc.edu/system/Network/admin/bootpc.v045.tgz

     Me ton initrd (poy periexetai sto Linux 2.0), 8a mporousame na to
     kanoyme na doylecei arketa omorfa. Sthn pragmatikothta, o initrd
     einai panta mia proxwrhmenh lush gia pio leptomereis ry8miseis.


  ·  Gia ekkinhseis basismenes monaxa sto bootpd, ayto pi8anotata den
     xreiazetai, mia poy to Linux 2.0 periexei epishs kai thn dynatothta
     na xrhsimopoioume to BOOTP anti toy RARP. (Akribestera, mporoume na
     kanoyme compile kai ta duo ston pyrhna, kai kerdizei opoio
     apokrinetai taxutera.)

  ·  Sto directory ths tekmhriwshs toy source toy kernel, yparxei ena
     arxeio poy periexei tekmhriwsh gia to NFS-Root.

  ·  Yparxei ki ena patch poy trigyrnaei, poy mas epitrepei na kanoyme
     swapping epanw sto NFS. Moy to steilane (kata th diarkeia mias
     periodoy, opoy eixa pollh doyleia), alla katafera na xasw to e-
     mail. :(

     Pi8anotata 8a to breite sto http://www.linuxhq.com/ , sto tmhma me
     ta "anepishma" patches.


  ·  To public PGP kleidi moy mporeite na to breite kanontas finger sh
     dieu8ynsh andreas@ag.or.at . To apotupwma einai : F1 F7 43 D5 07 C4
     6C 87  BF 6B 33 A2 2C EE 5A F9.