large block device support missing in 3.7.1?

[duby229]

Under the menu heading "Enable the block layer" there should be an option called "Support for large (2TB+) block devices and files" which is required for just about every modern filesystem, but it seems to be missing. Without it, I cant get my / partition to mount r/w....

Am I missing something obvious? I looked all through the menuconfig and couldnt find it. Without that option ext4 is worthless. and I dont know what happened to it.

Any help would be awesome. if you guys need more information I'll gladly get it for you.

EDIT: I know that there are some kernel options that only become visible if some prerequisite is checked, does this option also have a prereq that needs checked for it to be visible?

[droste]

Are you running a 32bit kernel?
The option is only visible with 32bit kernels:

Symbol: LBDAF [=n]
Type : boolean
Prompt: Support for large (2TB+) block devices and files
Defined at block/Kconfig:26
Depends on: BLOCK [=y] && !64BIT [=y]
Location:
-> Enable the block layer (BLOCK [=y])

[duby229]

Are you running a 32bit kernel?
The option is only visible with 32bit kernels:

Symbol: LBDAF [=n]
Type : boolean
Prompt: Support for large (2TB+) block devices and files
Defined at block/Kconfig:26
Depends on: BLOCK [=y] && !64BIT [=y]
Location:
-> Enable the block layer (BLOCK [=y])

ok yeah that is interesting.... Yeah I'm running a 64bit kernel....

So if that option is not required for 64bit, then my problem is something entirely different than what I thought. This is a typed out as closely as I could remember of the exact error message dmesg gave me. I cant get a kernel log because the / fs is mounting ro and so it isnt being written to disk.

EXT4-fs (sdd3): mounted filesystem with ordered data mode
VFS: Mounted root (ext4 filesystem) readonly on device

[duby229]

here is some info if it helps at all....

/dev/sdd1 /boot ext2 defaults 1 2
/dev/sdd3 / ext4 defaults 0 1
/dev/sdd2 none swap sw 0 0


default 0
timeout 0

title Gentoo Linux
root (hd0,0)
kernel /boot/vmlinuz root=/dev/sdd3 rootfstype=ext4

Really this should be all thats required to boot. I dont understand why its mounting / ro

[droste]

I'm not sure what exactly is needed to boot from grub1 with an ext4 root without initrd/initramfs, but a quick google search brings up this:
http://forums.gentoo.org/viewtopic-t-880313.html

It states that you are probably missing devtmpfs in your kernel config:

CONFIG_DEVTMPFS=y
CONFIG_DEVTMPFS_MOUNT=y

[duby229]

well, i did not have those options in my kernel, so i added them and rebuilt it, but i am still getting exactly the same problem.... however according to dmesg devtmpfs is being loaded after the kernel mounts the fs ro..

[duby229]

I couldnt figure this problem out, so I decided to re-install on the tried and true ext3...... exactly the same problem..... I'm completely stumped. I dont have a useable os, and I have no idea what is wrong so I can fix it.

[crazycheese]

I have "rw,errors=remount-ro" for my / disk in fstab, instead of "defaults".
There is also nothing wrong mount it as ro, so long you make relevant directories rw. For example server hardening use that.
But assigning ro to whole / is stupid. Try change this in your fstab.

I don't think tmpfs has anything to do with it.

[crazycheese]

There could also be other causes. If you post dmesg somewhere, it could really allow to help you.
Also, you could try compile and boot older kernel with exactly same config and look if it works, just to narrow the issue down.