How to repair the BOOTSECTOR of a FAT32X active partition?

[pointertovoid]

Please forgive the elementary question but...

I see clearly the advantages of Ntfs over Fat32 and imagine FatX as a Fat64.

What improvement could bring FatX over Ntfs?

[jaclaz]

Please forgive the elementary question but...

I see clearly the advantages of Ntfs over Fat32 and imagine FatX as a Fat64.

What improvement could bring FatX over Ntfs?

I don't see any senceful question, elementary or not.

What the heck is "FatX"?

jaclaz

[Tripredacus]

FAT32X? Wikipedia is very elementary about it.

The latter type (partition 0x0C) is also named FAT32X in order to indicate usage of LBA disk access instead of CHS. On such partitions, some CHS-related geometry entries in the EBPB record, namely the number of sectors per track and the number of heads, may contain no or misleading values and should not be used.

[jaclaz]

FAT32X? Wikipedia is very elementary about it.

The latter type (partition 0x0C) is also named FAT32X in order to indicate usage of LBA disk access instead of CHS. On such partitions, some CHS-related geometry entries in the EBPB record, namely the number of sectors per track and the number of heads, may contain no or misleading values and should not be used.

NOT only elementary, also much VAGUE if not plainly WRONG.

There is NO DIFFERENCE whatsoever in the BPB between a bootsector created on the SAME device by the SAME OS by any "proper" tool, on partitions marked with ID 0B or 0C,

http://www.win.tue.nl/~aeb/partitions/partition_types-1.html

this is still connected to the PLAINLY WRONG idea that a Partition ID is anything more than a Partition ID, see:

http://homepage.ntlworld.com./jonathan.deboynepollard/FGA/determining-filesystem-type.html

and - if we are talking of actually booting from that partition - the H and S correct values are VITAL on Windows NT systems, because of some "botched" or "relic of good ol' CHS days" in the actual bootsector CODE (and this applies to NTFS too).

See:

http://www.911cd.net/forums//index.php?showtopic=21702&st=129

The whole idea of calling a FAT32 "FAT32X" is "botched", there is only a FAT32 filesystem, that can be accessed through BOTH CHS and LBA if below the CHS limit or only through LBA if over it (both in size and position on disk).

But the question by pointertovoid was about "FatX", which is a particular filesystem for the Xbox:

http://en.wikipedia.org/wiki/File_Allocation_Table#FATX

that has clearly nothing to do with FAT32 (and with this thread) and FAT64 does not simply exist, it is the WRONG name given sometimes to exFAT:

http://en.wikipedia.org/wiki/ExFAT

jaclaz

[pointertovoid]

My fault, I had mistaken it for exfat, sorry.

[jaclaz]

My fault, I had mistaken it for exfat, sorry.

Then the advantage could be that exFAT is seemingly faster than NTFS:

http://reboot.pro/17255/

http://thessdreview.com/Forums/software/1834.htm

Though of course there is nothing in the above except for the sentence:

(exFAT in my benchmarks has produced the fastest results)

and as we discussed here, the reliability of benchmarks and their actual being representative of "real life usage" has to be evaluated carefully.

It would "make sense", in the sense that theoretically a FAT32 should be faster than NTFS (it needs to read less data to get to the file you want at least until the number of files grows to very high numbers), but, as seen here:

at least in some applications it has been somehow "dumbed down" by the good guys at MS.

See also the very detailed:

http://www.uwe-sieber.de/usbstick_e.html

exFAT, being more similar to FAT32 and being also been "pushed" by the same MS guys, could have been optimized, see also:

http://www.ntfs.com/ntfs_vs_fat.htm

It is only slightly faster on USB sticks along results of this test (also already mentioned in the given thread), but only in a few of the many benchmarks:

http://blog.testfreaks.com/information/usb-flash-drive-comparison-part-2-fat32-vs-ntfs-vs-exfat/

jaclaz

Edited July 22, 2012 by jaclaz

[DiracDeBroglie]

Since you are using tinyhexer, you may find my little (as always half-@§§ed ) scripts for it, handy.

Here:

http://reboot.pro/8734/

jaclaz

I'm using your 3 scripts, and indeed those are extremely handy. Great added value to Tiny Hexer, those scripts have been very helpful to analyse USB Flash Drives where the MBR is sometimes missing. There is one disadvantage though with Tiny Hexer, there is no userfriendly editor to edit the partition table or any figures like 'sectors before' the PBR. I still use the old PowerQuest's Partition Table Editor (PTEDIT32.EXE), which works just fine. I'm not sure but I think you probably use also another utility for fixing MBRs and PBRs; if I recall correctly it start with HD..... , or something.

johan

[DiracDeBroglie]

You are falling in the "Access is denied" issue with Windows 7, right?

It is one of the "nice" protection features.

See:

http://reboot.pro/12413/

jaclaz

About the error message "System Error." "Code: 5." "Access is denied." when using Tiny Hexer, I tested LockDismount v0.3.0.0 (LD) and it works, at least on non-system drives (as mentioned in the link you gave) like USB Flash Drives. A drawback of LD is that it locks the entire HDD while in fact I only wanted to edit with Tiny Hexer a few sectors of one particular volume or partition on the system HDD. In my case I wanted to test Tiny Hexer by editing just a few empty dummy and meaningless sectors in the recovery partition (which sits on the system HDD). Upon trying to save away the altered test sector in Tiny Hexer I got then the error message. Using LD, LD tried to lock ALL the volumes on my system HDD and showed FAILED for all of the locking attempts -- a pity LD does not work solely on just one particular volume/partition, in stead of on entire HDDs.

I went on to create a few virtual HDDs, or vdisks, in Disk Management and dropped the *.vhd files in a primary partition on the system HDD. To my surprise Tiny Hexer could save away the edited sectors in those vdisks without causing the "Access is denied" error; so no need at all to use LD. An extra check after reboot of the computer revealed the sectors where indeed altered/updated. Although the *.vhd files of the vdisks were located on the system HDD, Tiny Hexer had somehow "direct" disk access to the vdisks.

Annoying thing with my vdisks though is that I have to re-attach them after each reboot.

BTW, I did not get any "Access is denied." error from the old PowerQuest's Partition Table Editor (PTEDIT32.EXE) when saving away an edited PBR on one of the partitions on the system HDD. It looks like Win7 gives direct disk access to some old software, but to some other old software (like Tiny Hexer) it doesn't.

j

[DiracDeBroglie]

There is NO DIFFERENCE whatsoever in the BPB between a bootsector created on the SAME device by the SAME OS by any "proper" tool, on partitions marked with ID 0B or 0C,

http://www.win.tue.nl/~aeb/partitions/partition_types-1.html

this is still connected to the PLAINLY WRONG idea that a Partition ID is anything more than a Partition ID, see:

http://homepage.ntlworld.com./jonathan.deboynepollard/FGA/determining-filesystem-type.html

and - if we are talking of actually booting from that partition - the H and S correct values are VITAL on Windows NT systems, because of some "botched" or "relic of good ol' CHS days" in the actual bootsector CODE (and this applies to NTFS too).

See: http://www.911cd.net/forums//index.php?showtopic=21702&st=129

jaclaz

Using DISKPART, I changed the type of my recovery partition from 0C (FAT32X) to 0B (FAT32), made the partition then active and restarted my computer. The computer booted immediately into my recovery partition without any problem. It looks like 0C and 0B are indeed the same.

j

[jaclaz]

I'm not sure but I think you probably use also another utility for fixing MBRs and PBRs; if I recall correctly it start with HD..... , or something.

Naah, I suggest often Hdhacker, but just as a tool to backup/restore the sectors.

http://dimio.altervista.org/eng/

Normally I use the dsfok tollkit, (command line) to do the same:

and I use my own little spreadsheet to calculate values I later carve by hand with TinyHexer, see:

jaclaz

[DiracDeBroglie]

and I use my own little spreadsheet to calculate values I later carve by hand with TinyHexer, see:

jaclaz

Got your spreadsheet from http://reboot.pro/2959/#entry74116 second version. WAAAAAAW, very impressive, very colorful. Don't have much time but I managed to perform a few small tests with CHS changes and then see the newly calculated result in LBA. This could be a very handy tool in conjunction with other tools that can write directly to the disk, like Tiny Hexer.

j