Exactly what is a legacy BIOS system ?
A legacy BIOS system is one whose firmware behaves essentially the same as the IBM PC/AT model... Where the mechanism of interaction with an OS is primarily in the form of interrupts. It also initializes the processor in 16-bit real mode, which is why every x86 processor today STILL starts in real mode : it's a de facto standard, that's very restrictive, considering it was conceived 25 years ago.
Thanks for clarification.
There are limits to technology, old or new. It tries to give unique IDs as far as possible. Anyway this could not have been Vista +. XP did suck in a few ways.
Under XP I discovered that when CMD.EXE invoked REG.EXE to READ (not modify) a key
and piped both STDOUT and STDERR to the same log file,
for keys that had sub-keys that had no access there would be simultaneous answers on both output streams for the same interrogation,
and MOSTLY both streams were logged, but sometimes neither were logged, and at other times only one was logged but not the other.
XP was successful better than 99% of the time when my batch script and the output log file were in partition C:\
When I moved only the log file destination to a partition at the other end of the HDD,
the success rate fell below 90%.
The problem was perfectly cured by disabling the output cache
(I think it may have been called "Enable Safely Remove")
Perfect cure - but Windows started up 3 times slower.
You are right - XP sucks.
- Robust and fault tolerant partition tables
- Well known partition type for bootloaders
- No primary-logical nonsense
- No clashes in disk type IDs
- Clashes are definitively solved with GUIDs
- Can even contain other partition tables nested
I have heard previously that GPT partition tables are fault tolerant, but do not see how that is possible.
An MBR has only two tables, I think they are called Primary and Extended
Break the primary and you lose everything.
break the extended and you lose all the Logicals.
BUT you have only two such tables to be broken, and as of 9 months ago the Professional licensed version of Minitool Partition Wizard was NOT capable of REPAIRING a broken GPT Partition Table,
even though it could shrink and extend GPT partitions.
I understand that every GPT partition is preceded by its own 3 MB GPT Table and that one GPT table links to the next GPT Table,
which MIGHT be the complication that Minitool Repair could not cope with.
If you have 128 partitions :-
Using MBR you have only 2 tables that may be broken,
(and 4 or 5 years ago freeware Mintool version 4.? fixed my Laptop which had lost ALL 7 partitions.)
Using GPT you have 128 tables that may be broken, and that loses all the subsequent partitions,
unless of course there are "redundant" backward pointing links to traverse the chain in the reverse direction,
and it is harder to find a tool for repairing GPT partition Tables,
and you have almost 400 MB consumed in GPT tables.
I am very willing to learn how GPT fault tolerance can deal with an accident to GPT Tables.
4. No clashes in disk type IDs
5. Clashes are definitively solved with GUIDs
That was NOT my experience under 64 bit Windows 7 Ultimate + SP1,
when normal start-up from cold allocated
Disk 0 W.D.C. 600 GB style GPT
Disk 1 Samsung 930 GB style MBR
Disk 2 OCZ 56 GB style MBR (primary system drive)
After countless visits from power-on into BIOS and then to Windows and a successful launch,
my next attempt resulted in the WDC having its complicated GUID replaced by the same 8 hexdigit ID as the Samsung,
After THAT stupidity Windows compounded its errors by WRONGLY choosing to put the Samsung OFFLINE.
Consequently :-
The WDC drive was useless and out of action because Windows saw an MBR style Disk ID that had no valid partitions,
The Samsung drive was useless because Windows had put it OFFLINE,
and as a result Windows lost access to the partitions that held "Pagefile.sys" and %TEMP%
I have not yet found any tool that will change an MBR ID into a GUID without requiring me to initialize the WDC and losing all the data.
and the fact that some of these tools disable GPT capability on freeware versions is a PRICELESS benefit of MBR.
Which? Not any more.
Both Minitool and Macrium had freeware versions restricted to MBR Disks a couple of years ago.
I agree those two products have recently removed those restrictions,
but I thought it probable that their competitors might either be in the process of catching up and not yet there,
or their competitors may have "accelerated" development and left the Beta testing for unsuspecting users.
Sorry, but thirty years of working in software and systems development has made me a little cynical.
Regards
Alan
