Fw: jaký HDD?

Mali sme taku sukromnu mailovu "flame-debatu" o 48 bitovom adresovani, tak
to skusim poslat aj sem, mozno to niekomu pomoze.

Zaroven by som sa chcel opytat _linuxakov_ - od akej verzie kernelu
je linux za vodou? Alebo 48 bitove adresovanie zvladal vzdy???

--cut--
1. If the problem with 48-bit LBA means hard drives can only be used up to a
maximum capacity of 137 GB, why can't I just partition my 48-bit LBA hard
drive into multiple partitions each less than 137 GB to get around the
problem?

That will not work. If you try it and your system does not meet the
requirements necessary for 48-bit LBA, data can become corrupted on
partitions which extend beyond the 137 GB limit. The problem with 48-bit LBA
involves the absolute sector addressing on the hard drive not simply the
address relative to the beginning of each partition on the hard drive. For
example, let's say you have a 160 GB hard drive where you have created two
partitions. The first is 137 GB and the second 23 GB. In order to properly
read and write data to the second 23 GB partition, 48-bits of address are
needed to access the correct sectors on the hard drive. Without 48-bit LBA
support, drivers with only 32-bits of addressing will only be capable of
addressing up to 137 GB on the hard drive.
--/cut--

Doteraz pouzivane 28 bitove adresovanie vie smerovat 2^28 (2 na 28-mu)
sektorov - 268 435 456 po 512 bytov (268 435 456 * 512 = 137 438 953 472)
co dava limit 128 / 137.4 GB - podla toho ci tie B podelis 1024 (ako to
rata takmer kazdy) alebo 1000 (ako to rataju na stranke
http://www.48bitlba.com ).

Ked ti OS, ktory nevie 48 bit LBA zapise hocico na 268 435 457-mi
(268 435 456 + 1) sektor, tak to v skutocnosti zapise na sektor cislo
1 - a tam je obvykle tabulka rozdelenia disku.
Nezalezi na tom, na akom logickom disku je ten 268 435 457-mi sektor.
Aj ked je disk rozsekany na viac logickych particii, tak particie za
hranicou 128 / 137,4 maju cislo sektora vyssie ako spominany...
Sektory sa totiz nezacinaju cislovat od 1 pri kazdom logickom disku, ale
su cislovane absolutne - od zaciatku disku (1) az na koniec v kuse
(disk 160 GB priblizne 335 544 320).

OS ktore 48 bitove adresovanie nevedia - w9x a Me, w2k, XP bez SP (ako
je na tom NT4 neviem).

Pre stare win-y nie je riesenie cez MS; ale ak sa nemylim, je to mozne
riesit na MB s Intel 8xx chipsetmi a softom Intel Application
Accelerator Driver.

Vo w2k so SP3 sa da zapnut podpora v registroch:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\atapi\Parameters
pridat kluc typu DWORD s nazvom "EnableBigLba" a hodnotu "1"

Pre XP je riesenie nainstalovat aspon prvy SP - SP1.

Samozrejme treba 48-bit LBA compatible BIOS alebo PCI ATA radic
s podporou 48-bit LBA. Mam dojem, ze v tomto pripade sa obmedzenie
biosu obist nijako neda, aj keby OS velke LBA podporoval. V tomto
pripade totiz nejde o to, ze by BIOS disk nevidel, ale o to ze nan nevie
korektne zapisovat udaje na spominanou hranicou...

MilanK