[Solved]GPT partition size issue

[xboxboy]

Hi all.
A bit of an interesting one. I have an image for an ARM device that I've dd'ed to a usb flash drive. It boots, but gets stuck during boot with the following:

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GPT:Primary header thinks Alt. header is not at the end of the disk.
GPT:31116287 !=31266815
GPT:Alternate GPT header not at the end of the disk
GPT:31116287 !=31266815
GPT: Use GNU Parted to correct GPT errors.
 sda: sda6 sda7
sd 0:0:0:0: [sda] Attached SCSI removable disk


Now, I've tried to run GUI gparted, but it wont run properly: I have to shutdown, and on shutdown it flashes some partition error quickly.

Next I run:

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[root@localhost Downloads]# gdisk /dev/sdj
GPT fdisk (gdisk) version 0.8.8

Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present

Found valid GPT with protective MBR; using GPT.

Command (? for help): v

Problem: The secondary header's self-pointer indicates that it doesn't reside
at the end of the disk. If you've added a disk to a RAID array, use the 'e'
option on the experts' menu to adjust the secondary header's and partition
table's locations.

Identified 1 problems!



So, I believe this is just an issue from dd'ing an image on to a different size drive: I just need to correct the GPT and it wil be fine. I'm unsure what/where to go to from here.

Many thanks

[jiml8]

Look at the tool gdisk.

[doktor5000]

That's what he used to query the disk - maybe he should press ? ...

[xboxboy]

Thanks for looking at this guys. GPT is totally new to me, and TBH, I can't make sense of it. Diskdrak can see the partitions fine. There are three partitions on the usb.

I've looked at:
http://www.rodsbooks.com/gdisk/
http://manpages.ubuntu.com/manpages/lucid/man8/gdisk.8.html

And, yes, pressing entering ? does bring up the same options. I just find the manual pages and descriptions very broad. ie. I don't understand how my situation fits the options available, and what the process is for repairing this header issue.

[martinw]

I think gdisk is suggesting the right option to use, but the message is a bit misleading. What it refers to as the experts' menu is probably this option:

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r   recovery and transformation options (experts only)


The 'e' option inside this menu is described as

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e   load main partition table from disk (rebuilding backup)


Rebuilding backup sounds like what you need to do (backup = alternate = secondary - would be nice if they used the same word everywhere!)

Try it. The worst that can happen is that you'll have to copy the image onto your flash drive again.

[xboxboy]

@martinw

Thanks, I will try that: I have a fresh copy on the USB to try: I'll have a go when I get home.

[xboxboy]

@MartinW

That worked perfect!

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Problem: The secondary header's self-pointer indicates that it doesn't reside
at the end of the disk. If you've added a disk to a RAID array, use the 'e'
option on the experts' menu to adjust the secondary header's and partition
table's locations.

Identified 1 problems!

Command (? for help): r

Recovery/transformation command (? for help): e
Warning! This will probably do weird things if you've converted an MBR to
GPT form and haven't yet saved the GPT! Proceed? (Y/N): y

Recovery/transformation command (? for help): w
Warning! Secondary header is placed too early on the disk! Do you want to
correct this problem? (Y/N): y
Have moved second header and partition table to correct location.

Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING
PARTITIONS!!

Do you want to proceed? (Y/N): y
OK; writing new GUID partition table (GPT) to /dev/sdj.
The operation has completed successfully.


It didn't boot completely: But I've got another problem: I think the image is for a SD card, but I've got it on usb, so once the usb drive mounts it crashes.