1 Topic by bezenek (edited by bezenek 2015-04-30 21:53:29)

  • Registered: 2015-03-23
  • Posts: 6

Topic: Fix for "bad geometry: block count exceeds size of device" Mount Error

I enlarged the root partition size using "make menuconfig."  However, when I try to mount the root partition, I get an error "bad geometry: block count exceeds size of device."

This tells me I need to change the partition table to match the new partition size is specified in "make menuconfig".

Where can I modify this?

Thank you,

Todd

  • Registered: 2015-03-23
  • Posts: 6

Re: Fix for "bad geometry: block count exceeds size of device" Mount Error

Additional information:

It looks like the "device" is defaulting to 102400 blocks, and does not increase when I change the size of the root partition past 100M in the configuration.  As a result, I see message like this in my log when I try to mount the root partition:

# For a 150M partition:
EXT4-fs (sda2): bad geometry: block count 153600 exceeds size of device (102400 blocks)

# For a 200M partition:
EXT4-fs (sda2): bad geometry: block count 204800 exceeds size of device (102400 blocks)

So, what/where is setting this arbitrary 102400-block device size?

-Todd

  • Registered: 2015-03-23
  • Posts: 6

Re: Fix for "bad geometry: block count exceeds size of device" Mount Error

The fix for this is to force the partition table to be re-read.  This pulls in the correct partition size so it can then be mounted.

Partition size before partition table re-read:

> toddb@fidusb $ sudo blockdev --getsize64 /dev/sda2
> 104857600

The size is equivalent to 100 MiB.  It should be 150 MiB.

Then force the re-read and check the size again:

> toddb@fidusb $ s blockdev --rereadpt /dev/sda
> toddb@fidusb $ s blockdev --getsize64 /dev/sda2
> 157286400

This is the correct size of 150 MiB.

-Todd

p.s. I assume the original value is coming from the filesystem superblock.  This suggests a bug in genext2fs, but that's only a guess.

  • Registered: 2013-02-16
  • Posts: 665

Re: Fix for "bad geometry: block count exceeds size of device" Mount Error

Please file a bug report for that.

- You should state what steps you took to hit that bug.
- State which version you compiled (BB or trunk)
- You should attach output of "./scripts/diffconfig.sh"

Since https://dev.openwrt.org/changeset/45517 there is no genext2fs in trunk so it might be a bug with the new way to create an image.