2.6.20-rc6 ramdisk problem

["Michal Piotrowski" <michal.k.k.piotrowski@gmail.com>]

Hi,

I want to create a large ramdisk - 1GB

CONFIG_BLK_DEV_RAM=y
CONFIG_BLK_DEV_RAM_COUNT=1
CONFIG_BLK_DEV_RAM_SIZE=4096
CONFIG_BLK_DEV_RAM_BLOCKSIZE=1024

kernel comman line: ramdisk_size=1000000

$ LANG="c" sudo /sbin/mkfs.ext2 /dev/ram0
mke2fs 1.39 (29-May-2006)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
125184 inodes, 250000 blocks
12500 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=260046848
8 block groups
32768 blocks per group, 32768 fragments per group
15648 inodes per group
Superblock backups stored on blocks:
       32768, 98304, 163840, 229376

Writing inode tables: done
Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 22 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.

$ LANG="c" sudo mount /dev/ram0 /mnt/ram0/
mount: wrong fs type, bad option, bad superblock on /dev/ram0,
      missing codepage or other error
      In some cases useful info is found in syslog - try
      dmesg | tail  or so

$ LANG="c" sudo /sbin/tune2fs -l /dev/ram0
tune2fs 1.39 (29-May-2006)
/sbin/tune2fs: Bad magic number in super-block while trying to open /dev/ram0
Couldn't find valid filesystem superblock.

dmesg
EXT2-fs: Magic mismatch, very weird !
VFS: Can't find an ext2 filesystem on dev ram0.

With ramdisk_size=500000 everything is ok.

machine
CPU P4 (ia32)
2 GB RAM

Is this is a hardware (arch) or software limitation? Maybe a bug?

Regards,
Michal

--
Michal K. K. Piotrowski
LTG - Linux Testers Group
(http://www.stardust.webpages.pl/ltg/)
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