1. Zagon in zaustavitev računalnika

2. Kaj mora administrator razumeti?
Zaporedje dogodkov pri zagonu sistema.
Metode, ki jih uporabimo za spreminjanje zagonskega zaporedja.
Kako izbiramo alternativne zagonske naprave.
Delovanje programov “boot manager” in “boot loader”.
Kako pravilno zaustavimo sistem.

3. Zakaj je potreben zagon ?
Aparaturna oprema ne ve, kje leži operacijski sistem in kako naj ga naloži.
Za to potrebujemo poseben program – “bootstrap loader”.
Na primer: BIOS – Boot Input Output System.
“Bootstrap loader” locira jedro (operacijskega sistema), ga naloži v pomnilnik in sproži njegovo izvajanje.
V nekaterih primerih pa preprost “bootstrap loader” poišče na disku bolj kompleksen zagonski program, ga naloži v pomnilnik, ta pa nato naloži jedro (kernel).

4. Kako poteka zagon (boot) ?
Dogodek “reset” na CPE (vklop računalnika, ponovni zagon) povzroči, da se programski števec nastavi na preddoločeni naslov v pomnilniku. Sproži se program “Bootstrap” na tej lokaciji.
Ta program je pomnjen v ROM, saj je pomnilnik RAM takrat v neznanem stanju. ROM je tako primeren za inicializacijo, nanj pa tudi ne vplivajo virusi.

5. BIOS Info BIOS na matični plošči. CMOS pomnilnik
pomni ključne začetne podatke
CMOS Memory is battery-powered and holds key startup information including the date, time and system startup parameters.
A flash memory BIOS differs from ROM BIOS in that they can changed. These changes might include better support for different types of hardware as well as to fix any sort of problems.

6. Interakcija BIOS

7. BIOS Setup

8. Naloge ob zagonu
Diagnostika, ki določi stanje stroja. Če je diagnostika uspešna, se zagon nadaljuje.
Izvedba “Power-On Self Test” (POST), ki preveri, ali naprave, ki sestavljajo računalnik, delujejo.
BIOS gre preko predkonfiguriranih naprav in poišče tisto, ki je zagonska (bootable). Če take naprave ne najde, sledi obvestilo o napaki in zagon se zaustavi.
Initializacija registrov CPE, krmilnikov naprav in vsebine pomnilnika. Zatem sledi nalaganje operacijskega sistema.

9. POST Preveri prisotnost pričakovanih naprav
(le osnovno delovanje, avtomatsko preverjanje)

10. Zagonski postopek (boot procedure)

11. Bootstrap Loader

12. Terminologija zagonskega mehanizma
Loader
Naloži kodo (običajno) z diska v pomnilnik in sproži izvajanje te kode)
Bootloader / Bootstrap
Program, ki naloži “prvi program” (jedro oziroma kernel)
Boot PROM / PROM Monitor / BIOS
Fiksna koda, ki je ob vklopu računalnika “že naložena”
Boot Manager
Program, ki nam omogoča izbrati “prvi program”, ki naj bo naložen
Loading is an important and often over-looked OS concept. Loading is increasingly accomplished “on-demand” via dynamic linking-loaders. The Linux kernel module mechanism is essentially an advanced application of dynamic linking/loading.
People often mistakenly think that “bootstrap” refers to boot laces.
The “bootstrap” metaphor refers to the nonsensical image of someone lifting themselves up off the ground by their own bootstrap. The impossibility of this image adds to the mystery of the boot process.
There are lots of related types of “firmware”: ROM, PROM, EPROM, EEPROM, NVRAM, Flash RAM and who knows what else. PROM in “Boot PROM” or “PROM Monitor” is used informally. In the SPARC architecture, these are actually contained in EEPROMs.
The phrase “first program” is in quotes for a reason. Often the first program loaded is itself a boot manager, like LILO.
LILO introduces the concept of “chain loaders”. Why not have one loader load another loader which might load another loader…

13. Kaj je nalagalnik (loader)?
Program, ki kopira kodo (običajno z diska) v pomnilnik in sproži izvajanje te kode.
Nalagalnik
(loader)
pomnilnik
CPE
A great reference is “Linkers & Loaders” by John Levine Morgan Kaufmann 2000.
Loaders are also sometimes responsible for allocating memory, setting protection bits, updating memory maps, etc.
disk
Kopira kodo
Sproži kodo
koda
koda

14. Kdo pa naloži nalagalnik?
Seveda je tudi nalagalnik le program, ki leži v pomnilniku. Kako pa je tja prišel?
Potrebujemo “nalagalnik nalagalnika” …
Pomnilnik
Nalagalnik
(loader)
disk
Executables are stored on disk (by compilers and assemblers) in specific formats. The original UNIX format was known as a.out (hence the default output filename for the C compiler). a.out was superceded by COFF and more recently by ELF (Executable and Linking Format). DOS has .COM and .EXE.
Loaders usually only understand how to “interpret” and load files in a single format. Often an OS only allows a single executable format.
Linux supports multiple executable formats. (In Linux lingo they are called “binfmts” for “binary formats”.) ELF is widely used.
So, what exactly *is* the Linux (or UNIX) loader? Many people would say “ld” but ld is the “Link eDitor”. It’s a linker. Not a loader.
Loading is accomplished in the UNIX-world indirectly via the exec family of system calls. exec essentially “overlays” the current process image with the specified executable image file. exec is a loader!
We will see in later chapters that Linux goes even further in “hiding” the loader. Executables are typically “loaded” by just setting up the memory map with all pages initially marked “absent”. Virtual memory then “pages in” the executable image as needed. This is “lazy” or “on-demand” loading.
In the above, cat is probably “loaded” by a fork/exec from the shell. The shell was started by login, which was started by getty, which was started by init. init is created by the kernel during kernel initialization. So how is the kernel loaded?

15. Bootstrap Loader (Bootloader)
Program, ki naloži “prvi program”
Pogosto “večstopenjski”: primarni, sekundarni
Terja podporo firmware (“hardware bootstrap”)
PROM
(firmware)
Pomnilnik
bootloader
CPE
Boot device?
Floppy
Primarni
Primarni
Jedro
(kernel)
Jedro
(kernel)
CD ROM
Sekundarni
Sekundarni
mreža

16. Zagon PC
Intel X86 firmware naloži “boot sector” na 0x7C00 in nanj prenese nadzor v realnem režimu (limita 640K )
pomnilnik
Power On Self Test (POST)
Proženje INT 19h (bootstrap)
Izbira zagonske naprave (boot device)
Nalaganje zagonskega sektorja (boot sector)
floppy: prvi sektor
trdi disk: MBR (mboot) ali “partition boot block” (pboot)
Verifikacija “magic number”
Izvajanje boot sektorja (primary bootloader)
0xc700
boot sektor
CPE
When you power-on the Intel, it reads a “start address” from location 0xfffffff0 and jumps to that location. In the standard PC configuration, this address is the BIOS entry point. Strangely, the location 0xfffffff0 is also part of BIOS (the high 64K of memory). This indirect mechanism allows Intel chips to be used in non-PC settings.
Everything happens in real-mode so some memory mapping tricks are used to make the high BIOS addresses reachable in real-mode.
After executing the POST, BIOS enters the bootstrap interrupt handler and tries to load a boot sector using the BIOS-defined order. For a floppy, BIOS always loads the first sector. For a hard disk, the first sector which is a Master Boot Record (MBR or mboot) containing some code and a partition table are loaded. The loaded code searches the partition table for the active (bootable) partition. If the MBR is from the active partition we are done. If the active partition is some other partition, the MBR code loads the boot sector of that partition. This is sometimes referred to as a partition boot sector or pboot. There are further complications for extended and logical partitions.
Eventually the “correct” boot sector is loaded. Each boot sector contains a “magic number” to verify that it is, indeed, a boot sector. If the magic number is verified, then the boot sector code is executed.
BIOS (64K)
0xfffffff0
BIOS_start
2GB

17. Naloge ob zagonu (nadaljevanje)
Ko najde zagonsko napravo, naloži BIOS njen zagonski sektor (boot sector) in ga sproži. V primeru trdega diska je to na MBR ( master boot record ) in pogosto ni specifično za določen operacijski sistem.
Koda MBR preveri tabelo particij (partition table) in išče v njej aktivno particijo. Če jo najde, naloži koda MBR zagonski sektor (boot sector ) te particije in sproži njegovo izvajanje.
Zagonski sektor (boot sector) je pogosto specifičen za dani operacijski sistem. V mnogih operacijskih sistemih je glavna naloga kode zagonskega sektorja nalaganje in proženje jedra (kernel), ki nato nadaljuje zagonske postopke (startup).
MBR Partition table Particija Particija Particija

18. Zagon z diska pri Windows 2000

19. Sekundarni zagonski nalagalnik

20. Sekundarni zagonski nalagalnik
Če ni aktivne particije ali če izbere particijo (lahko s pomočjo vnosa uporabnika), naloži njen zagonski sektor.
Primeri sekundarnih zagonskih nalagalnikov:
GRUB – GRand Unified Bootloader
LILO – LInux LOader
NTLDR – NT Loader
Sekundarnim zagonskim nalagalnikom pravimo tudi zagonski upravniki (boot managers)
MBR Partition table Partition Partition Partition
Boot Superblock Free space Inodes Root dir. Files &
block management directories

21. LILO: LInux LOader Prilagodljiv zagonski upravnik, ki omogoča:
Izbiro jeder Linux
Nastavitev časovnih parametrov zagona
Zagon jeder, ki niso Linux
Nastavljanje konfiguracij
Značilnosti:
Leži v MBR ali zagonskem sektorju (boot sector) particije
Ne ve nič o datotečnem sistemu
LILO was developed by Almesberger as a way of adding flexibility to the boot process, primarily as a means for Linux to co-exist with DOS. There are literally dozens of boot “scenarios” that are possible with LILO..
LILO is the Intel boot manager. Different architectures have variants. MILO for Dec Alpha systems and SILO for SPARC systems are two notable family members. PowerPC platforms use BOOTX and YABOOT. Other, less popular, Intel boot loaders include: LOADLIN, BOOTLIN, SYSLINUX, etc.
LILO comes with an extensive User’s Guide and a succinct but valuable Technical Overview. Both of these are available in the LILO distribution tarball.
A key issue with boot loaders is whether they have knowledge of the filesystem structure. LILO does not and this explains the need for a “block map” and running the “map installer”. Adding knowledge of filesystem structure simplifies booting but significantly increases the size and complexity of the bootloader. In effect, it contains a minimal (“stand-alone”) filesystem implementation. Solaris OpenBoot uses secondary bootloaders that understand a filesystem (ufsboot, nfsboot).
/sbin/lilo must ask the kernel to identify the disk blocks containing the kernel to load as well as other configuration and data blocks. LILO uses these low-level SHC (sector/head/cylinder) addresses to find relevant sectors without needing to “decode” the filesystem structure

22. Komponente LILO /sbin/lilo (“map installer”) /etc/lilo.conf
/boot/boot.b
Konfiguracijska datoteka
/boot/chain.b
/boot/map
/boot/vmlinuz
The “map installer” is controlled by the text file lilo.conf which identifies the desired boot scenario and details available boot images.
Rerun /sbin/lilo anytime boot-related files change! That includes lilo.conf, the kernel itself, the boot loaders, the disk partition structure, etc.
Newer versions of LILO keep most files in /boot by default. Under RedHat 6.1 the compressed kernel image is called vmlinuz.
The actual primary and secondary bootloaders (the “real” LILO) live in the file /boot/boot.b. You can generate your own if you are clever enough but most people use the supplied loaders.
Certain boot scenarios require loading additional loaders (for example, to boot off a logical partition). LILO supports this via the concept of a “chain loader”. The default chain loader is available as /boot/chain.b.
The file /boot/map contains the actual sector map with a variety of other information. See the Technical Overview for details.
Finally, the /boot directory may also contain an initial ramdisk image (initrd) used during boot.

23. Primer konfiguracijske datoteke lilo.conf
boot=/dev/hda
map=/boot/map
install=/boot/boot.b
prompt
timeout=50
default=linux
image=/boot/vmlinuz
label=linux
initrd=/boot/initrd img
read-only
root=/dev/hda1

24. Primer konfiguracijske datoteke grub.conf
default=0
timeout=10
splashimage=(hd1,2)/grub/splash.xpm.gz
password --md5 $1$opeVt0$Y.br.18LyAasRsGdSKLYlp1
title Red Hat Linux
password --md5 $1$0peVt0$Y.br.18LyAasRsGdSKLYlp1
root (hd1,2)
kernel /vmlinuz ro root=LABEL=/
initrd /initrd img
title Windows XP
rootnoverify (hd0,0)
chainloader +1

25. GRUB “Lupina za čas zaganjanja (Boot time shell)
GRUB interaktivni ukazi
Sproti (on the fly) izvaja novo konfiguracijo
Dinamično privzeto konfiguriranje
Lahko zaganjamo druge OS

26. Primerjava LILO in GRUB
Tradicionalna
Če zamenjamo “kernel” ali spremenimo zagonsko konfiguracijo, moramo reinstalirati v “master boot record”
GRUB
Nova
Fleksibilna
Interaktivni ukazi

27. Zagon z diska s pomočjo LILO
LILO izpisuje niz “LILO boot:”
BIOS naloži zagonski sektor na 0x7c00 ter se sam prestavi na 0x9a00
Nastavi sklad naloži sekundarni nalagalnik na 0x9b00
Nadzor prevzame sekundarni nalagalnik
naloži “block map” na0x9d200 Izpiše komandno vrstico
In čaka na vnos uporabnika ali iztek časa “timeout”
On a modern PC this all happens in the blink of an eye so it loses a bit of its excitement but it’s good to know about when something breaks in the middle of the boot process.
A two-digit error code is printed after the first L if a media failure or geometry error has occurred.
If only LI is printed, there might be a problem with /boot/boot.b.
If only LIL is printed or LIL? or LIL- then there was a problem loading and decoding the map file.

28. LINUX: od zagona do zaustavitve

29. Življenski cikel sistema: gor in dol
Zagon (Booting)
Inicializacija jedra (Kernel Initialization)
Prvi proces: init
Zaustavitev sistema (shutdown)
start_kernel
Vklop
Izklop
Boot
Kernel Init OS
Init
izvajanje
Shut down
init
shutdown
LILO
sleep? (hlt)
Much of this chapter is devoted to details of booting which can be quite complex. Reviewing the details helps to dispel some of the mystery surrounding the process and provides an appreciation for the complex hardware, firmware, software coordination required.
We spend time looking at the standard Intel boot manager LILO as well as introducing the Skiff bootloader.
Kernel initialization is staged. Low-level, device-dependent initialization finally yields to high-level, device-independent initialization. Each category has initialization dependencies. Certain things must be done before other things.Each logical Linux subsystem has one or more _init() functions that are called during this process.
Processes 0 and 1 are discussed. Process 1 (init) is responsible for all user-level process creation.
Shutdown is also staged but not as complex as startup. /sbin/shutdown and init cooperate to bring the system down gently.
Linux enthusiasts continue to stretch the bounds. We review some creative thinking about the boot process.
Power management is an increasingly important OS responsibility and part of the system lifecycle.

30. LINUX: od zagona do zaustavitve

31. Inicializacija jedra Preveri sistemske naprave
Identifikacija specifičnih naprav
Jedro (Kernel)
Zagotavlja, da bo strojna oprema delala to, kar hočejo programi

32. Inicializacija jedra Preskus bistvenih naprav
CPE, konzola, pomnilnik
Preskus strojnih podsistemov
I/O vodila, omrežni vmesniki, trdi diski, CD-ROM pogoni, disketni pogoni, pomnilne naprave

33. Inicializacija jedra Inicializacija datotečnega sistema
Logical volume manager subsystem
RAID
SCSI naprave
Particije na trdem disku
Spreminjanje konfiguracije jedra
/usr/src/linux/make menuconfig or xconfig
rdev
Boot loader parameter

34. LINUX: od zagona do zaustavitve

35. Zaporedje procesov, ki zaživijo pri zagonu nekaterih sistemov
Zagon UNIX (Linux) cp
Zaporedje procesov, ki zaživijo pri zagonu nekaterih sistemov

36. init()
init() začne življenje kot nit jedra in konča kot proces na uporabniškem nivoju (/sbin/init)
init/main.c:init
acquire “the big kernel lock” on a multiprocessor (MP)
perform high-level initialization – do_basic_setup()
free __init memory
release lock
try to exec (in user space) the init process
panic if unsuccessful
We are now running concurrently with idle. (Actually idle runs until it is rescheduled by a timer interrupt. The scheduler notices that init wants to run and lets it.) So grab the “big kernel lock”. This is a no-op on a uniprocessor. It is important to identify “lock points” even in uniprocessor code but conditional compilation avoids any extra overhead.
Call do_basic_setup() for some “real work” as the comment says.
Release memory used by init code and data. Release lock.
Try to exec /sbin/init, passing appropriate parameters. exec will setup a process image in user space so this is a transition from kernel to user space. init() looks in several places if exec fails. In desperation it tries to exec a shell. If that fails it calls panic() which halts the system with extreme prejudice.
/sbin/init doesn’t really need stdin or stdout but we set them up in case we exec a shell or a user-specified init replacement.

37. Init?
Init je predhodnik vseh procesov (vendar brezposeln) “seje” otroke
Lokacija: /sbin/init
Teče v uporabniškem načinu (user mode) (do jedra dostopa preko sistemskih klicev)

38. Kaj naredi Init ob zagonu?
Pregleda datoteko /etc/inittab
Preko nje glede na nivo izvajanja požene skripte, ki se nahajajo v datotekah v imeniku /etc/rc.d
servisi za beleženje sistemskih obvestil
vzpostavitev mreže
mrežni strežniki (splet, pošta...)
...
Požene procese, ki omogočijo prijavo na sistem na
tekstovnih terminalih
lahko tudi grafični uporabniški vmesnik

39. Nivoji izvajanja UNIX Run Levels – nivoji izvajanja
pove na kakšnem nivoju (načinu) je sistem
single user (vzdrževanje) in
multi-user (brez in z omrežnimi servisi)
parameter pri poganjanju procesa init pove v kakšen način naj se računalnik postavi
Tudi Windows imajo nivoje:
Multi-user
Safe Mode
Safe mode with networking

40. Nivoji izvajanja v init
0: Ustavljen sistem (pripravljen na izklop)
1: Enouporabniški režim
2: Večuporabniški režim brez mrežnih datotečnih sistemov
3: Večuporabniški režim z mrežo
4: navadno ni v uporabi
5: Večuporabniški sistem z GUI
6: Reboot režim
S,s: Single user mode (brez /etc/inittab)

41. Init
Katere servise init zaganja in njihov vrstni red glede na nivo izvajanja določa
datoteka /etc/inittab
programi v lupini (skripte) v imenikih /etc/rc.d, ki so urejeni po nivojih izvajanja
Ena od prednosti uporabe skript pri zagonu je, da jih lahko preverjamo in spreminjamo
skripte lahko ročno pokličemo z argumenti stop in start in preverjamo, ali delujejo pravilno
tak postopek je priporočljiv, saj lahko odkrijemo napake, ki bi prekinile zagon in povzročile, da bi bil sistem neuporaben.

42. Primer iniciacijskega skripta

43. Init Lokacija: /sbin/init Uporablja funkcije iz knjižnjic v jeziku C
Preveri in montira datotečni sistem
Požene demone za beleženje sistemskih obvestil
Požene procese getty, ki na virtualne terminale izpišejo najavko login
Omreženje
Strežniki WEB strani
Poslušanje miši

44. Spreminjanje nivojev izvajanja
Naslednji ukazi so tipično rezervirani spreminjanje nivojev:
UNIX:
Ukazi shutown, telinit oz. init
Windows:
Ukaz shutdown

45. Najava uporabnikov (login)
Ko je jedro naloženo, smo še v privilegiranem režimu. Če bi se sedaj lahko prijavili (login) kot uporabnik, bi imeli sistemske privilegije.
Vendar program "login" po preverjanju gesla vrne lupino kot drug proces z nižjimi privilegiji. Jedro procesu "login" zaupa. Če bi ga nadomestili oziroma vanj vdrli, bi lahko dobili administratorsko lupino (root shell) za vsako prijavo.

46. Zaustavitev (shutdown)
Zapis “bufferjev”: da ne bi izgubili podatkov in okvarili datotečni sistem, uporabimo /bin/shutdown
shutdown onemogoči logiranje, zahteva od “init”, da pošlje vsem procesom signale SIGTERM in SIGKILL (jih torej konča).
Buffered writes are not the only reason why “pulling the plug” is a bad way to shut down a Linux system. “Graceful termination” is important for all sorts of “transaction oriented” activities.
Buffered writes are “flushed” via the “sync” command. Old UNIX lore has it that a system admin should type sync three times in rapid succession and then pray before shutdown.
Actually the non-deterministic nature of disk access makes it impossible to *guarantee* that all writes have been flushed but it works almost all the time.
The kernel demon responsible for periodically flushing write buffers is bdflush. It interacts with a user space demon that is controlled by /sbin/update.
The low-level halt and reboot commands are now smarter than they used to be. If you are not in runlevel 0 or 6, they will call shutdown for you to keep your from coming to harm.

47. Zaporedje zaustavitve
Shutdown [-h/r]
Blokirano je ponovno prijavljanje
Vsem procesom pošljemo signal SIGTERM in jim tako povemo, da se sistem ugaša
Procesi se čisto zaključijo
Procesu init poščjemo signal, da naj spremeni nivo izvajanja
Privzeto: 1, -h flag 0, -r flag 6

48. Zaustavljanje Odmontiranje particije
Strukturne informacije datotečnega sistema
Shutdown -F (fsck)
“Journaling” datotečnega sistema
shranjenje zapisa transakcij o spremembah datotečnega sistema
Odgovor pri ponovnem zagonu sistema

49. Upravljanje s pomnilnikom
Halting in the idle process
idle process executes hlt on Intel
low-power consumption mode
Suspending the system
patches for suspending to disk
APM: Advance Power Management
laptop standard power management
ACPI: Advanced Configuration and Power Interface
new comprehensive standard from Intel-Microsoft
Power-management is essential for mobile systems
This is a big issue. Several years ago, before energy-saving mechanism were widely available, something like 12% of the US powergrid was used by idling computers!
Energy-saving mechanisms sometimes end up fighting with each other and with screen-savers. There is a need for a coordinated standard.
“Fast-booting” from a system image is an interesting technique significantly slows shutdown to allow writing the image.
Making an OS “power consumption aware” requires rethinking the design of lots of subsystems: device-drivers, scheduling, etc. An OS kernel is a precarious balancing act between flexibility, performance, cost and reliability. Designers are preeminently concerned with performance and reliability but as power consumption becomes an increasingly important “cost”, design decisions must be reconsidered.
See the Ecology-HOWTO for more details on “green” machines.

50. Dodatek
Ali imam na sistemu tudi sekundarni zagonski nalagalnik, če imam en sam operacijski sistem ?
Stari sistemi tega morda nimajo. Danes pa so celo Windows nameščeni s privzetim sekundarnim zagonskim nalagalnikom (NTLDR). Tudi Linux je običajno nameščen z LILO ali GRUB kot privzetim zagonskim nalagalnikom.
Tako se nam lahko zgodi, da Windows ne moremo zagnati in se pojavi obvestilo “NTLDR missing”. To se zgodi, če primarni zagonski nalagalnik ne more prenesti nadzora na NTLDR, ki je morda pokvarjen ali pomotoma zbrisan.

51. Dodatek
Kakšen je vpliv na zagonski sektor (boot sector) in zagonski nalagalnik (boot loader), ko namestimo dva operacijska sistema, na primer Windows in Linux , v dve ločeni particiji ?
Predpostavimo, da smo najprej namestili Windows. Privzeti zagonski nalagalnik, nameščen v MBR, je NTLDR in vsebuje podatke o aktivni particiji z Windows. Ko na ta sistem namestimo še Linux, namestitev zahteva prekritje sekundarnega zagonskega nalagalnika, ki identificira aktivni particiji tako z Windows kot z Linux. To nam daje možnost izbire operacijskega sistema ob zagonu.
Če pa smo najprej namestili Linux in šele nato Windows, bo “Windows Installer” prekril MBR s svojim lastnim zagonskim nalagalnikom, ki ne spozna aktivne particije Linux. To pa je problem, ki ga rešimo s ponovno namestitvijo sekundarnega nalagalnika, ki zna ugotoviti oba operacijska sistema in ponuditi izbiro. .

52. O tabeli particij
When installing an OS on a computer from scratch, here is how the partition table is created.
The hard disk is denoted as “hda” where hd=hard disk, and the third letter could mean the hard-disk on the system. For e.g. the first hard disk is “hda”, the second is “hdb”.
When the partitioning is done, “hda0” is the place of MBR. “hda1” is the primary partition. Then a secondary partition may be created which is further subdivided into logical drives. Another OS could be installed on any of these logical drives.
hda0 – MBR
hda1 – Primary Partition e.g. Windows XP
hda2 – Secondary Partition
hda3 – Logical Drive 1 (FAT32 or NTFS partition)
hda4 – Logical Drive 2 (FAT32 or NTFS partition)
hda5 – Logical Drive 3 (Swap for Linux Partition)
hda6 – Logical Drive 4 (Root for Linux Partition)
The above example is a simple example. Specific cases can be different.