How is the disk signature in ARC path defined?
Dylan
ARC path of Win2K/XP's boot.ini?
Dylan
Jiri Tuma
in MBR between code and partition table. It is designed to identify disk
device even its physical position in machine is changed. It is important for
forced drive letters, fault tolerant partition sets and volume and stripe
sets. Related information is stored in registry under DISK key. This code is
stored in MBR, because it is disk specific information and every disk
(usable by NT system) has MBR. This code has nothing to do with OS loading
and it is not used inside boot.ini file than.
ARC path is most left part of operating system record in boot.ini (study NT
resource kit, chapter 19 for more info). This part (left from equal sign) is
nothing more than pointer to controller,disk and partition and path to
folder on it containing system files.
Partition pointer has 4 parts:
First part (most left) is multi(0) or scsi(c) where c is number of disk
controller. In case of multi() notation NT loader will use BIOS standard
disk services to access system files (which is limited to the first 7.8GB of
disk space), while in case of scsi() notation it will load NTBOOTDD.SYS file
and use it as disk driver to access system files. Usually it is renamed copy
of primary disk controller driver used by NT core. Controllers are numbered
from 0 in physical order from driver point of view - so it is practically
always 0.
Next part is disk(lun) where lun is LUN (SCSI ID) of target disk (in multi()
notation this parameter is not used and should be set to 0)
The third part is rdisk(x) where, in case of multi(), x is number of disk in
physical order starting from 0 or, in case of scsi(), x is LUN of primary
disk (ie. practicaly always 0).
Last (most right) part is partition(n), where n is number of partition
starting from 1 (! all other parameters are starting from 0!). Note that
partition ordering is similar to standard lettering procedure, ie. primary
partitions first than logical disks. This means that if you have one primary
partition, than extended partition with some logical drives and some free
space after it (for example due extending of RAID) and if you will create
another partition on this rest of disk space all your logical disk numbers
will be shifted up by one. If you have your OS installed on logical disk,
you should to edit boot.ini before reboot or you will get Inaccessible Boot
Device message. If you add new primary partition to the end of disk by disk
admin it will warn you about this.
Dylan <dnc...@hotmail.com> píąe v diskusním
příspěvku:boo4pm$26p4$1...@news.hgc.com.hk...
Bjorn Landemoo
The signature part is only used when the disk controller doesn't support
INT13 extensions, or if SCSI BIOS is disabled, see this MS Knowledge Base
article:
http://support.microsoft.com/?id=227704
You might also want to read my answer to your previous question.
Best regards
Bjorn
--
Bjorn Landemoo - mv...@landemoo.com - http://landemoo.com/
Microsoft MVP - Windows Server Networking