Sfor Posted May 30, 2011 Share Posted May 30, 2011 (edited) Thanks to the ESDI_506.PDR patch and updated HDD controller drivers it is possible to work with hard drives bigger than 137GB. But it appears there is another problem with drives above 2TB. So I have a few questions related to this problem.- Does the problem start at 2TB or just above it?- What is the cause (system, driver, BIOS)?- Can it be avoided by reducing the drive capacity through a proper drive configuration?- Is it related to the sector size greater than 512 bytes?-------------------------------------------------Conclusions:- Problem starts with drives larger than 2TB.- The cause is the old partition structure standard.- Windows 98 has an issue with partitions larger than 1TB. Edited June 5, 2011 by Sfor Link to comment Share on other sites More sharing options...
allen2 Posted May 30, 2011 Share Posted May 30, 2011 Explanation there. Link to comment Share on other sites More sharing options...
dencorso Posted May 30, 2011 Share Posted May 30, 2011 The MBR uses addresses of 32 bits to point to the partitions. This means 2^32 (=4,294,967,296) possible sector addresses. If the HDD has 512 bytes sectors, this means 4,294,967,296 * 512 = 2 TiB. Moreover, the DOS/NTFS boot record also has a 32-bit sector count field, resulting in the same limitation. Of course, if using 4 kiB sectors, this limit becomes to 16 TiB. Now, this is just theoretical, because it's not clear, at this time, how well Win 9x/ME supports 4 kiB sectors. However, RLoew has found out that there is a bug in VFAT.VxD, so that, due to that bug, a patch is required to use safely partitions > 1 TiB. But if no partitions > 1 TiB are used, its safe to use a 2 TiB HDD with Win 9x/ME. Link to comment Share on other sites More sharing options...
Sfor Posted May 30, 2011 Author Share Posted May 30, 2011 Right. Then it is safe to use 2TB drives, as long as they are working with 512B sectors.I know the Seagate has a technology of firmware related sector size translation. So it is not necesary to use any additional software with their drives. I'm curious if it is safe to buy just any 2TB drive. Or, perhaps one should carefully examine drives to be 512B sector size compatible. Link to comment Share on other sites More sharing options...
allen2 Posted May 30, 2011 Share Posted May 30, 2011 2TB drive are not really 2TB in size because, for hard drive makers, 1TB is 1 000 000 000 000 instead of 1 099 511 627 776. So unless you buy 3TB hard drive or use raid you won't get any problem. Link to comment Share on other sites More sharing options...
rloew Posted May 30, 2011 Share Posted May 30, 2011 The MBR uses addresses of 32 bits to point to the partitions. This means 2^32 (=4,294,967,296) possible sector addresses. If the HDD has 512 bytes sectors, this means 4,294,967,296 * 512 = 2 TiB. Moreover, the DOS/NTFS boot record also has a 32-bit sector count field, resulting in the same limitation. Of course, if using 4 kiB sectors, this limit becomes to 16 TiB. Now, this is just theoretical, because it's not clear, at this time, how well Win 9x/ME supports 4 kiB sectors. Windows 9x does not support 4KiB Sectors. I have written a Patch as part of my TBPLUS package to support 4KiB Sectors. This is needed if you want to use the USB 3TB Drives.With 4KiB Sectors, the limit is 16TiB per Partition. DOS 7 can be Patched to support 32KiB Sectors allowing 128TiB Partitions.I have also developed an extended MBR format that allows Drives to support 512TiB with 512B Sectors, 8PiB with 4KiB Sectors. This is required to use Internal 3TB Hard Drives.Right. Then it is safe to use 2TB drives, as long as they are working with 512B sectors.I know the Seagate has a technology of firmware related sector size translation. So it is not necesary to use any additional software with their drives. I'm curious if it is safe to buy just any 2TB drive. Or, perhaps one should carefully examine drives to be 512B sector size compatible.All 2TB Drives use 512B Sectors externally and can be used with Windows 9X.Western Digital pioneered the use of 4KiB Sectors Internally. These "Advanced Format" Drives can be used, but will run slowly if accesses to the Drive are not aligned on 4KiB Boundaries. Partitions have to be specifically Formatted to ensure alignment. Link to comment Share on other sites More sharing options...
dencorso Posted May 30, 2011 Share Posted May 30, 2011 I stand corrected. Sure: 4,294,967,296 * 4,096 = 16 TiB. I need to get more sleep... Thanks, RLoew! I've corrected my previous post and the quotation of it, in red, to highlight the correction.BTW, I've been using an External USB 2.0 Seagate Expansion 1500 GB with a Seagate Barracuda LP ST31500541AS (5900 rpm) 1500 GB HDD inside, for one year already, if not more, without any issues. It's partitioned into 3 roughly equal sized partitions. Although I've never had the chance to use a 2 TB HDD yet, I agree with RLoew and allen2: it has to be safe, because it's real size is 1.82 TiB. But it should not be used as a single partiton, unless RLoew's patch is used.In fact, there was an issue, but not related to size: all green Barracudas have an auto spin-down on idle feature. Neither Win XP SP3, nor Win 98SE, do understand it, so that every time it spins down, the OSes think it has been disconnected and reconnected, and redetect it, causing it to spin up again. The solution to this issue is to use the Seagate Manager Software, which accompanies the drive, to set the spin down time to "Never", effectively disabling that feature. I don't know whether the Seagate Manager works on 9x/ME, because I did it on XP. In any case it must be done just once, so it's not really fundamental to have the Seagate Manager working on 9x/ME. Link to comment Share on other sites More sharing options...
Sfor Posted May 31, 2011 Author Share Posted May 31, 2011 (edited) I'm working with a 1.5TB Seagate drive and a 1TB WD internal drives, currently. The biggest partition size is 512GB. No problems detected, so far.The Seagate proclaims, their sector size translation firmware with SmartAllign technology is significantly faster, then solutions used in other drives. So, the difference between working with 512B and 4096B sectors is not a big one. They claim, their translation firmware is almost as fast as the advanced format alligning software running on a PC. Edited May 31, 2011 by Sfor Link to comment Share on other sites More sharing options...
Tripredacus Posted June 1, 2011 Share Posted June 1, 2011 I have seen on some sites that GPT Disks are not supported in DOS and Win9x. Is there some technical limitation in those OSes that cannot be patched to support GPT? Link to comment Share on other sites More sharing options...
rloew Posted June 1, 2011 Share Posted June 1, 2011 I have seen on some sites that GPT Disks are not supported in DOS and Win9x. Is there some technical limitation in those OSes that cannot be patched to support GPT?Neither recognizes the GPT format. GPT Partition scanning code would have to be added. It would be easier to replicate the GPT Partitions into an MBR replacing the dummy bridge MBR normally used in GPT Drives. Link to comment Share on other sites More sharing options...
jaclaz Posted June 1, 2011 Share Posted June 1, 2011 Just for the record, in some cases a "hybrid" can be made, reference:http://www.rodsbooks.com/gdisk/http://www.rodsbooks.com/gdisk/hybrid.htmljaclaz Link to comment Share on other sites More sharing options...
rloew Posted June 1, 2011 Share Posted June 1, 2011 Just for the record, in some cases a "hybrid" can be made, reference:http://www.rodsbooks.com/gdisk/http://www.rodsbooks.com/gdisk/hybrid.htmljaclazBasically what I was saying. Unfortunately, it appears that no possible configuration insures total compatability.Patching DOS and Windows 9x may help. Special MBR Code and/or a DDO may be needed. Link to comment Share on other sites More sharing options...
erpdude8 Posted June 2, 2011 Share Posted June 2, 2011 (edited) I have seen on some sites that GPT Disks are not supported in DOS and Win9x. Is there some technical limitation in those OSes that cannot be patched to support GPT?Neither recognizes the GPT format. GPT Partition scanning code would have to be added. It would be easier to replicate the GPT Partitions into an MBR replacing the dummy bridge MBR normally used in GPT Drives.and GPT based partitions require 64bit operating systems!they won't work on 32bit OSesspeaking about the 2TB hard drive limit, FAT32 and NTFS can support up to 2TB volumes and no greater than that Edited June 3, 2011 by erpdude8 Link to comment Share on other sites More sharing options...
rloew Posted June 3, 2011 Share Posted June 3, 2011 I have seen on some sites that GPT Disks are not supported in DOS and Win9x. Is there some technical limitation in those OSes that cannot be patched to support GPT?Neither recognizes the GPT format. GPT Partition scanning code would have to be added. It would be easier to replicate the GPT Partitions into an MBR replacing the dummy bridge MBR normally used in GPT Drives.and GPT based partitions require 64bit operating systems!they won't work on 32bit OSesspeaking about the 2TB hard drive limit, FAT32 and NTFS can support up to 2TB volumes and no greater than thatThe 2TiB Partition limit can be increased by using larger Sectors, either actual or simulated by translation software. I have done it both ways using 3TB Hard Drives . Link to comment Share on other sites More sharing options...
allen2 Posted June 3, 2011 Share Posted June 3, 2011 (edited) I have seen on some sites that GPT Disks are not supported in DOS and Win9x. Is there some technical limitation in those OSes that cannot be patched to support GPT?Neither recognizes the GPT format. GPT Partition scanning code would have to be added. It would be easier to replicate the GPT Partitions into an MBR replacing the dummy bridge MBR normally used in GPT Drives.and GPT based partitions require 64bit operating systems!they won't work on 32bit OSesspeaking about the 2TB hard drive limit, FAT32 and NTFS can support up to 2TB volumes and no greater than thatEverything is false:- GPT partitions are supported by 32bits MS OS since Windows 2003 SP1 as said in the notes.- NTFS max size is by design 16exabytes (about 16 millions of Gigabytes) and as implemented since windows 2003 SP1 256TB.- FAT32 partitions might go up to 8TB Edited June 3, 2011 by allen2 Link to comment Share on other sites More sharing options...
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