Community
cancel
Showing results for 
Search instead for 
Did you mean: 
jhane2
New Contributor I
2,804 Views

GPT vs MBR

Jump to solution

I've seen an issue with the partitions on the Edison when changing the sizes and was just poking around a little bit. I notice that when flashing the device, u-boot prints out that is creating a the partition table using GPT. Out of curiosity I installed the gptfdisk and here is what I see

root@dirty:~# gdisk /dev/mmcblk0

GPT fdisk (gdisk) version 1.0.0

Caution: invalid backup GPT header, but valid main header; regenerating

backup header from main header.

Warning! One or more CRCs don't match. You should repair the disk!

Partition table scan:

MBR: protective

BSD: not present

APM: not present

GPT: damaged

****************************************************************************

Caution: Found protective or hybrid MBR and corrupt GPT. Using GPT, but disk

verification and recovery are STRONGLY recommended.

****************************************************************************

================================================================================

root@dirty:~# gdisk /dev/mmcblk0p9

GPT fdisk (gdisk) version 1.0.0

Partition table scan:

MBR: MBR only

BSD: not present

APM: not present

GPT: not present

***************************************************************

Found invalid GPT and valid MBR; converting MBR to GPT format

in memory. THIS OPERATION IS POTENTIALLY DESTRUCTIVE! Exit by

typing 'q' if you don't want to convert your MBR partitions

to GPT format!

***************************************************************

Maybe I just don't understand what is going on here yet; however, I expected that if the partition table was GPT that the gdisk would work. Instead, the tools seem to indicate that it is not GPT, or at least not valid.

Anyone have any insight into what is going on here?

thanks,

jeff

1 Solution
Carlos_M_Intel
Employee
1,026 Views

Hi Jeff,

I'm sorry for the delay in our response. The GTP: damaged message seems to be related with the Edison using MMC as storage device and not a hard drive. Even though, you can ignore these messages as they are just warnings.

Regards,

Charlie

View solution in original post

10 Replies
Carlos_M_Intel
Employee
1,026 Views

Hi jeff,

I will investigate more about this but I would like to know if this is happening always, no matter the size of the partition.

Also, have you tried to use gptfdisk with the standard image not the custom one?

Regards,

Charlie

jhane2
New Contributor I
1,026 Views

results from a fresh from the box edison and then after flashing with ww18-15. But now there is that disturbing overlap message that I didn't see before.

jeff

marvel [2254] % cat foo

root@edison:~# cat /etc/version

edison-weekly_build_56_2014-08-20_15-54-05

root@bugger:~# gdisk /dev/mmcblk0

GPT fdisk (gdisk) version 1.0.0

Caution: invalid backup GPT header, but valid main header; regenerating

backup header from main header.

Warning! One or more CRCs don't match. You should repair the disk!

Partition table scan:

MBR: protective

BSD: not present

APM: not present

GPT: damaged

****************************************************************************

Caution: Found protective or hybrid MBR and corrupt GPT. Using GPT, but disk

verification and recovery are STRONGLY recommended.

****************************************************************************

Command (? for help): q

root@bugger:~# gdisk /dev/mmcblk0p9

GPT fdisk (gdisk) version 1.0.0

Partition table scan:

MBR: MBR only

BSD: not present

APM: not present

GPT: not present

***************************************************************

Found invalid GPT and valid MBR; converting MBR to GPT format

in memory. THIS OPERATION IS POTENTIALLY DESTRUCTIVE! Exit by

typing 'q' if you don't want to convert your MBR partitions

to GPT format!

***************************************************************

Warning! Main partition table overlaps the first partition by 18 blocks!

Try reducing the partition table size by 72 entries.

(Use the 's' item on the experts' menu.)

Warning! Secondary partition table overlaps the last partition by

33 blocks!

You will need to delete this partition or resize it in another utility.

# 3

root@bugger:~# cat /etc/version

weekly-146

root@bugger:~#

root@bugger:~# gdisk /dev/mmcblk0

GPT fdisk (gdisk) version 1.0.0

Caution: invalid backup GPT header, but valid main header; regenerating

backup header from main header.

Warning! One or more CRCs don't match. You should repair the disk!

Partition table scan:

MBR: protective

BSD: not present

APM: not present

GPT: damaged

****************************************************************************

Caution: Found protective or hybrid MBR and corrupt GPT. Using GPT, but disk

verification and recovery are STRONGLY recommended.

****************************************************************************

Command (? for help): q

root@bugger:~# gdisk /dev/mmcblk0p9

GPT fdisk (gdisk) version 1.0.0

Partition table scan:

MBR: MBR only

BSD: not present

APM: not present

GPT: not present

***************************************************************

Found invalid GPT and valid MBR; converting MBR to GPT format

in memory. THIS OPERATION IS POTENTIALLY DESTRUCTIVE! Exit by

typing 'q' if you don't want to convert your MBR partitions

to GPT format!

***************************************************************

Warning! Main partition table overlaps the first partition by 18 blocks!

Try reducing the partition table size by 72 entries.

(Use the 's' item on the experts' menu.)

Warning! Secondary partition table overlaps the last partition by

33 blocks!

You will need to delete this partition or resize it in another utility.

Carlos_M_Intel
Employee
1,026 Views

Hi jeff,

I'm still investigating about this. After using parted > print all are you still having "Partition Table: gpt for the /dev/mmcblk0" in the log? The mmcblk0 could have been set as GPT and the other ones can be set differently so that could be the reason of the MBR only/protected GPT damaged in your log

Regards,

Charlie

jhane2
New Contributor I
1,026 Views

Hello,

Running parted > print all didn't change anything but I wouldn't expect it to. Thanks for looking into this. Obviously the system is working, I'm just trying to understand if there is some kind of issue or not.

thanks,

jeff

Carlos_M_Intel
Employee
1,026 Views

Hi Jeff,

We would like to replicate your environment and do some tests. Did you build gptfdisk source, downloaded the package or did you installed it from a repo?

Regards

jhane2
New Contributor I
1,026 Views

I grabbed a recipe from somewhere and built it in my yocto environment. I can't access my other system right now so can't tell you exactly what the recipe is.

jeff

Carlos_M_Intel
Employee
1,026 Views

Hi jeff,

Do you remember if you used the openembedded-core layer from http://layers.openembedded.org/layerindex/branch/dizzy/layers/ OpenEmbedded Metadata Index - layers and this recipe http://recipes.yoctoproject.org/rrs/recipedetail/185/ Recipe reporting system - gptfdisk

If this was not the recipe you used, could you provide us .bb file?

Regards,

Charlie

jhane2
New Contributor I
1,026 Views

Not sure at this point so here is the recipe:

DESCRIPTION = "GPT fdisk is a disk partitioning tool loosely modeled on Linux fdisk, but used for modifying GUID Partition Table (GPT) disks. The related FixParts utility fixes some common problems on Master Boot Record (MBR) disks."

LICENSE = "GPLv2"

LIC_FILES_CHKSUM = "file://COPYING;md5=59530bdf33659b29e73d4adb9f9f6552"

DEPENDS = "util-linux popt ncurses"

SRC_URI = "${SOURCEFORGE_MIRROR}/${BPN}/${PV}/${BP}.tar.gz"

SRC_URI[md5sum] = "2061f917af084215898d4fea04d8388f"

SRC_URI[sha256sum] = "5b66956743a799fc0471cdb032665c1391e82f9c5b3f1d7d726d29fe2ba01d6c"

do_install() {

install -d ${D}${sbindir}

install -m 0755 cgdisk ${D}${sbindir}

install -m 0755 gdisk ${D}${sbindir}

install -m 0755 sgdisk ${D}${sbindir}

install -m 0755 fixparts ${D}${sbindir}

}

BBCLASSEXTEND = "native nativesdk"

Carlos_M_Intel
Employee
1,026 Views

Hi jeff,

Thank you, we are still investigating in order to identify why you are getting those messages while using gdisk.

Regards,

Charlie

Carlos_M_Intel
Employee
1,027 Views

Hi Jeff,

I'm sorry for the delay in our response. The GTP: damaged message seems to be related with the Edison using MMC as storage device and not a hard drive. Even though, you can ignore these messages as they are just warnings.

Regards,

Charlie

View solution in original post

Reply