Auugh! I think I screwed up! Easy2Boot on a 4TB USB drive???

One of my tried and true 2TB Easy2Boot USB Passport drives died a grisly death and I had to order a few more for replacements.  Not thinking I ordered 4TB ones.  Which of course have to be GPT.

Of course Grub4DOS refuses to install on a GPT disk.  I am afraid I already know the answer is NO, but is there any way around this?  I guess I could convert to 2TB and convert to MBR and throw away the last 2TB, but that sucks. 

E2B needs a standard MBR with following 'unused' sectors. So we can't have any fancy hybrid GPT partitions.

I think you just bought yourself a very useful offline backup drive...

One of my tried and true 2TB Easy2Boot USB Passport drives died a grisly death and I had to order a few more for replacements.  Not thinking I ordered 4TB ones.  Which of course have to be GPT.

 

Of course Grub4DOS refuses to install on a GPT disk.  I am afraid I already know the answer is NO, but is there any way around this?  I guess I could convert to 2TB and convert to MBR and throw away the last 2TB, but that sucks. 

Yes (but No), yes (but NO) and No.

1) Yes, it is entirely possible to keep the 4 TB disk as MBR if you use a "particular" partitioning (not up to debate) of 2 TB+2TB AND you use it ONLY with 7 or later[1], start from around here:

https://msfn.org/boa...comment-1142727

BUT this only works for disks that expose themselves as 512 bytes sectored, your disk 99.99% will expose 4 Kb and needs not any particular setup

2) Yes, it  is entirely possible to "install" grub4dos on a GPT disk and boot from it BUT you need a specific way to "install" it 

http://reboot.pro/to...o-gpt/?p=197690

BUT this only works for disks that expose themselves as 512 bytes sectored, your disk 99.99% will expose 4 Kb and won't boot from BIOS

3) No, as most USB eternal disks larger than 2 TB will be translated by the bridge/case/converter into 4 KB sector ones, that are NOT  BIOS bootable "standalone", so, very likely you can have it MBR just fine without any particular trick, but you won' t be able to boot it.

Unfortunately the NO prevail in the case of USB disks.

Wonko

[1] actually the first partition will be always accessible, the second won't to OS before 7

Thanks, I thought that was it. 

I bought (or rather the company bought) Three 4TB drives. On the first I simply setup as MBR and threw away the last 2 TB.  The other two I will use in conjunction with another Easy2Boot bootable USB drive to boot to and store the backups / data on the large new 4TB GPT disks.  Should work fine, kinda unhandy but I hope I remember to hold back to 2 TB next time. 

Is there a way to chainload Grub4Dos (specifically with Easy2Boot) from Grub2? I know Grub2 can use GPT disks. 

Is there a way to chainload Grub4Dos (specifically with Easy2Boot) from Grub2? I know Grub2 can use GPT disks.

Yes, but E2B requires an MBR partition for most things such as booting linux ISOs and .imgPTN files, etc.

It uses the partnew command for these.

So it's not a solution.

sorry.

@ Rootman

Try AIO Boot: https://www.aioboot.com/en/

 

AIO Boot uses Grub2 as the default boot loader. Grub2 is a powerful loader developed by GNU which supports both MBR and GPT and supports booting in both Legacy BIOS and UEFI. In addition, AIO Boot also supports to install Grub4dos, rEFInd, Clover, Syslinux and Enoch Chameleon. See more features of AIO Boot.

Download: https://sourceforge....ojects/aioboot/

I have been trying (on USB sticks, but it can be installed on large USB or internal HDs too) this free tool with very good results so far, and as it states in its page it supports MBR and GPT and supports booting in both Legacy BIOS and UEFI, the GPT capability may be a good feature for your needs (so you could use full size of disks, no need to be limited to 2 TB).

alacran

On the first I simply setup as MBR and threw away the last 2 TB. 

The point is that a USB 4 TB disk will 99.99% expose itself as 4 KB  sector.

Such a geometry is NOT bootable from BIOS.

If you prefer, there is no 2TB limit connected with BIOS/MBR, there is a limit with 2^32-1 sectors, that corresponds to the 2 TB limit IF the sector size is 512 bytes, and that is extended to around 16 TB in case of 4 KB sectors.

@Steve6375

It's not that the GPT prevents adding partition(s) in the three free slots, sure it would become a hybrid GPT/MBR style disk, but that is normally not a problem, the 4 KB sector is.

Wonko

The point is that a USB 4 TB disk will 99.99% expose itself as 4 KB  sector.

 

This must be one of the .01%, it presents itself as a true 512b drive, the 4K sector isn't an option. The manufacturer states that the advanced format is no longer an option and that XP compatibility is no longer available. 

I setup one to replace the one that blew out as a 2TB drive. As a 2 TB drive with my Easy2Boot partition on it, it works fine, the other 2 drives I just setup as non bootable 4TB drives.  I will use a thumb drive to boot to the system with the 4TB plugged in and use my backup utility to store the data on the 4TB drives.  It works, a little awkward, but It works. 

@ Rootman

 

Try AIO Boot: https://www.aioboot.com/en/

 

 

Download: https://sourceforge....ojects/aioboot/

 

I have been trying (on USB sticks, but it can be installed on large USB or internal HDs too) this free tool with very good results so far, and as it states in its page it supports MBR and GPT and supports booting in both Legacy BIOS and UEFI, the GPT capability may be a good feature for your needs (so you could use full size of disks, no need to be limited to 2 TB).

 

alacran

Alacran, I downloaded this utility, but can't seem to find proper instructions on how to chain boot to Grub4DOS correctly.  I could forgo booting to Linux ISOs and booting all my imgPRTN files on these drives if this would work for my regular Windows PE ISOs. Have you got a surefire guide on the proper syntax in the grub.cfg file to chain load grub4dos? 

Alacran, I downloaded this utility, but can't seem to find proper instructions on how to chain boot to Grub4DOS correctly.  I could forgo booting to Linux ISOs and booting all my imgPRTN files on these drives if this would work for my regular Windows PE ISOs. Have you got a surefire guide on the proper syntax in the grub.cfg file to chain load grub4dos? 

If you booted in Legacy BIOS mode, you will see a menu to boot Grub4dos from Grub2. Grub4dos does not support UEFI, sorry.

Edited by nguyentu, 12 June 2018 - 11:01 AM.

This must be one of the .01%, it presents itself as a true 512b drive, the 4K sector isn't an option. The manufacturer states that the advanced format is no longer an option and that XP compatibility is no longer available. 

Very good news

So you can use it in BIOS just fine, with 7 (and later) that will be able to see both 2 TB partitions and earlier OS's only capable of accessing the first one.

Easy2boot shouldn't have any issue with that, as (hd0,2) and (hd0,3) remain free partition slots.

Wonko

Very good news

 

So you can use it in BIOS just fine, with 7 (and later) that will be able to see both 2 TB partitions and earlier OS's only capable of accessing the first one.

 

Easy2boot shouldn't have any issue with that, as (hd0,2) and (hd0,3) remain free partition slots.

 

Wonko

I'm sorry, I have never fully understood most of the posts you write.  When I look at the manufacturers specs and Q&A the drives site they state that this drive cannot be used to it's full extent under XP or other OS as an MBR drive because the advanced formatting to make 4K sectors is no longer supported.  So it exposes itself as a regular disk with 512 byte sectors and must be GPT to use the full 4TB capacity.  If you mean something else by your statements I am afraid they are above me and I can't figure out what you are meaning. 

This WILL work with BIOS / MBR boot, but only if I set it to MBR disk type type and then create partitions that equal less than 2TB in size.  The remaining 2TB just sits there as a dead thing totally inaccessible. I did this to one of them in order to have another Easy2Boot bootable drive.  The other 2 I just set to GPT and formatted without any boot method for them. 

 

If you booted in Legacy BIOS mode, you will see a menu to boot Grub4dos from Grub2. Grub4dos does not support UEFI, sorry.

 

AIOCreator.exe, you can run it and integrate a lot of ISO files without having to use Grub4dos.

 

Edit:

The example menus are located in /AIO/grub/menuoff, you can refer to the script and manually add the menu for yourself.

 

Thanks again Nguyentu,  For some reason I am unable to get this to work.  I downloaded and installed it to the drive and I can't set it up with any ISO that I have, even using the supplied tools.  It gets 100% done with prepping the ISO and then errors.  Even when I reboot and choose the USB HDD after installing GRUB2 I ma dumped to the grub rescue command line with errors like unknown disk format. I set an 8mb partition first, a 150GB fat32 as a second and the rest as NTFS.  The disk type is GPT.  I am not sure how to proceed. 

Alacran, I downloaded this utility, but can't seem to find proper instructions on how to chain boot to Grub4DOS correctly.  I could forgo booting to Linux ISOs and booting all my imgPRTN files on these drives if this would work for my regular Windows PE ISOs. Have you got a surefire guide on the proper syntax in the grub.cfg file to chain load grub4dos? 

You need to forget a little about how grub4dos works (I have used grub4dos for a very long time to always boot my Iso files), AIO Boot do not need an Iso file to boot your WinPE.

It seems to me you did something wrong, let the tool do its work, do not force grub4dos install, let it install on your USB device the boot loaders by default when extracting to it. See: https://www.aioboot....en/#How-to-use 

I have been using it and you do not need to chain boot to grub4dos for booting WinPE's in fact I'm not using grub4dos to load WinPEs, just extract the boot.wim from your WinPE and run AIOCreator.exe from your USB device on Integrate Tab and select Windows, then WinPE 7/8.1/10 and your boot.wim, the tool will ask you for a name (no spaces on it please) wich will be used on boot menu too, and create a folder with this name and the boot.wim into it, same procedure for each WinPE.

Latter when booting from your USB device you may see your USB boot options twice, one for UEFI and one for MBR, select UEFI in your case (as you are using GPT partition) and on following menu select your WinPE.

I suggest you to install this utility to a USB stick and try with a single WinPE first to let you become familiar with the way it works. Usually first menu is a Grub2 menu, from it you select what to boot and your WinPE boot.wim is finally booted (chainloaded) by Windows bootmanager (UEFI or MBR respectively).

Attached is my UEFI BCD located on: H:\EFI\Microsoft\Boot (H = My USB stick).

alacran

I'm sorry, I have never fully understood most of the posts you write.  When I look at the manufacturers specs and Q&A the drives site they state that this drive cannot be used to it's full extent under XP or other OS as an MBR drive because the advanced formatting to make 4K sectors is no longer supported.  So it exposes itself as a regular disk with 512 byte sectors and must be GPT to use the full 4TB capacity.  If you mean something else by your statements I am afraid they are above me and I can't figure out what you are meaning. 

 

This WILL work with BIOS / MBR boot, but only if I set it to MBR disk type type and then create partitions that equal less than 2TB in size.  The remaining 2TB just sits there as a dead thing totally inaccessible. I did this to one of them in order to have another Easy2Boot bootable drive.  The other 2 I just set to GPT and formatted without any boot method for them. 

The whole point, or if you prefer the "novelty" of the (allow me "clever") approach I devised and proposed here:

https://msfn.org/boa...comment-1142727

is that there has been a lot of confusion (cannot say whether intentionally or by mistake) by the good MS guys (and by the various hard disk manufacturers) abut the exact nature of the 2 TB limit.

What has been written all over is that a disk bigger than 2TB cannot be accessed if MBR style.

This is FALSE.

The origin of the issue is that 2 fields in the MBR partition table entries, the "Sectors Before" and the "Number of Sectors" are 32 bit, and as such the biggest number you can store in that is 2^32-1, i.e. 4294967295 which, mutliplied by 512 makes 2199023255040 bytes, which is the advertised 2 TB "limit".

Actually you can have a first partition ending just short of sector 4294967295, and another partition following it with a size sightly less than 4294967295 sectors.

This way all the sizes "fit" in the respective fields.

Then - for *some* reasons - the XP disk drivers cannot access the second partition[1], BUT the Windows 7 ones (since they can access just fine the same extents when the disk is GPT) have no problems whatsoever with them.

So, out of a 4 TB disk (while still MBR style) you can fit:
1) a first partition almost 2 TB in size that will be accessible by *any* OS <- or up to 3 primary partitions as long as they are all contained in the first 2 TB

2) a last partition, up to almost 2 TB in size that will be accessible only by Windows 7  and later

Here:

https://msfn.org/boa...comment=1143244

you can find an image where you can see a Windows 7 with this setup, with a first partition of almost 2 TB and a second partition of roughly 600 GB on a 3 TB disk.

If you read the thread from the link I gave before up to the above, you will understand how the good MS guys do not support this partitioning scheme in diskpart or disk manager, so the partitioning needs to be done manually (but it is doable).

Of course it is "experimental", it is potentially "dangerous", etc., etc., but neatly offers you a way out to fully use the whole 4 TB disk while keeping it MBR and BIOS bootable.

The alternative (already given) is to have it GPT but make it anyway grub4dos bootable, though obviously "normal" automated tools like East2boot won't work with this latter scheme.

Wonko

[1] not fully tested, it may depend by the specific hardware/disk controller

@Wonko,

 

@Wonko,

 

Partitioning can start at $FFFFFFFF and total sector is $FFFFFFFF.

So we can use MBR for 4TB disk. Right?

 

 

Yep  , exactly, actually you will need to use some smaller values for first partition(s), so that the last partition remains "MB aligned".

I propose for the start of the last partition ("Sectors Before") address

4294965248

as.

4294965248*512=2199022206976

and:

2199022206976/1024/1024=2097151 MB

Wonko

Cool,

$FFFFFFFF = 4294967295.

4294967295 sector * 512 = 2199023255040 Bytes = 2097151,99951 MB.

Just create a partition that starts at 2097151 MB with size 2097151 MB, we will be able to take advantage of the maximum size on disk (4194302 MB). The total size of the remaining partitions should not be greater than 2097151 MB.

Cool,
 
$FFFFFFFF = 4294967295.
4294967295 sector * 512 = 2199023255040 Bytes = 2097151,99951 MB.
 
Just create a partition that starts at 2097151 MB with size 2097151 MB, we will be able to take advantage of the maximum size on disk (4194302 MB). The total size of the remaining partitions should not be greater than 2097151 MB.

OK, I didn't try Wonko's idea of carving the disk up into smaller partitions, it just doesn't fit my needs.

I did experiment more with AIOCreator.exe.  I dug up a 32GB stick and it installed and worked fine on it.  I formatted it all as FAT 32. I booted several of my ISO files from it and choose greb4dos when asked how to boot it.  When I tried to use the integrate tool on my PE ISO files each and every one of them failed with an error after it was completed suggesting I contact the author. 

I can't get it to install on my 4TB USB HDD though.  Grub2 insisted on having a small 8mb partition on the disk since it's a GPT disk.  I created a FAT32 partition behind it.  I tried various sizes from 30gb to 150gb. When I try to boot from it I get dumped to grub rescue prompt.

error: no such device: /AIO.sitecuatui.com.html.
error: unknown filesystem.
Entering rescue mode . . .
grub rescu> 

Whatever is happening it doesn't appear to like the partition scheme.

So, no joy.  I'll just have to stick with using the two 4TB disks and booting from a separate stick.  Thanks for your help.

@Rootman, You can click on the Tools button and install Grub2 here, without needing a small partition. Try this.

@Rootman, You can click on the Tools button and install Grub2 here, without needing a small partition. Try this.

I neglected to mention, I did that as well. I deleted all partitions on the 4TB USB HDD, created a single FAT32 150GB partition and installed AIO again from the exe. I used the tools and installed Grub2 legacy.  When I boot to I get the same exact thing - dumped to the rescue line.  After this I even copied all the files from the working UBS thumb drive to the 4TB USB HDD and it produced the same error.

Something about the 4TB USB HDD it does not like. 

EDIT:  I dug up a old 500GB USB HDD and installed AIO onto it, works like a charm.  I even set it to GPT and put in GRUB2 legacy, it still works. I also tried putting a 8mb partition in the front end and installed grub regular (?) with the GPT disk and it works.

I pulled out the 4TB drive again and did it the same way as the 500GB, and it doesn't work, dumps me to the grub rescue console.  Funny thing is, that it works when using the tool for qemu testing, it boots right to the menu.  From an actual PC it fails.  Something just doesn't like 4TB drives. 

Just an update:

nguyentu Thanks for the suggestions.  I tried AIO and was not able to get it to work on the 4TB drives.  For some reason GRUB2 will not work on these drive in legacy mode, it always drops to the grub command line.  Other smaller media I created with AIO boot up to legacy mode and EFI fine, so it's something with these drives.

I worked with the AIO author to get the integration feature of AIO to work on my Win PE ISO files.  These Winbuilder based ISO files seem to have something odd that kept AIO's integration from working.  Once we got them to work with he authors help, they would boot OK in legacy mode from a smaller USB stick to the wims - but not a one of them would run from the stick booted from EFI mode.  So that again puts my 4TB drives back in the dog house.

Lesson learned, remember the 2TB limit for grub4dos.  I'll just have to use these 4TB drives as data storage only and use another USB drive to boot to my PE instances.  I use these drives to make offline backups of the HDDs of PCs I am replacing.  I have to do a full backup and store the data for months, so I wanted fewer but LARGER USB drives to do it on.  I am midway through replacing the first 68 PCs, so the data is mounting up quickly

@ Rootman

From your last post:

 

I worked with the AIO author to get the integration feature of AIO to work on my Win PE ISO files.  These Winbuilder based ISO files seem to have something odd that kept AIO's integration from working.

I have had some problems to integrate MistyPE or ChrisPE boot.wim(s) on AIO, on my case reason was there were 2 images on boot.wim(s), so I had to delete first *.wim image and let only second *.wim image remain and rebuild the boot.wim files, once done this problem disappear.

To handle *.wim images I use wimlib_clc (fantastic GUI for wimlib-imagex), this is the very last version: http://reboot.pro/to...ta/#entry206470, you will also need to download wimlib-imagex from: https://wimlib.net/

alacran.

@ Rootman

 

From your last post:

 

I have had some problems to integrate MistyPE or ChrisPE boot.wim(s) on AIO, on my case reason was there were 2 images on boot.wim, so I had to delete first *.wim image and let only second *.wim image remain and rebuild the boot.wim files, once done this problem disappear.

 

To handle *.wim images I use wimlib_clc (fantastic GUI for wimlib-imagex), this is the very last version: http://reboot.pro/to...ta/#entry206470, you will also need to download wimlib-imagex from: https://wimlib.net/

 

alacran.

I peeked into the ISO and only see ONE wim file in the sources folder.  I assume this will show up in the ISO structure as a separate 'file' in the ISO folder structure?  

I'd really like to get an alternate system going as at some time or another I suspect legacy boot on new devices will be a thing of the past and therefore so will Easy2Boot and it's MBR requirements. I am not sure what's keeping AIO / GRUM2 from working on the 4tb drives, other smaller media works fine. GRUB2 just won't load in legacy mode on the 4TB drives.

Open the Iso file with 7zip, then go to sources\boot.wim and open it and you will see if there is one or two images contained into your boot.wim file.

All the boot.wim from install DVDs has always two images on it. Only second image is bootable.

Then almost all WinPE projects that use boot.wim from DVD source (I know only one exception) use only second image and some delete the first one, but other as MistyPE and ChrisPE do not delete first image and just live it there.

You may also use wimlib_clc to open your boot.wim and on info / delete tab you can see how many images are contained on your .wim files, also there you can select an image and with right click delete it and rebuild your .wim