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filesystemsmountext4ext2

Mounting ext4 mounts as ext2 in linux 4.4.0 [RHEL]


commands I executed

mkfs .ext4 -F /dev/xxx0

mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
524288 inodes, 2097152 blocks
104857 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2147483648
64 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632

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

mount -o dax /dev/xxx0 /mnt/ext4-xxx0

mount output

/dev/xxx0 on /mnt/ext4-xxx0 type ext2 (rw,relatime,seclabel,block_validity,barrier,dax,user_xattr,acl)

dmesg output

[ 2917.044866] EXT4-fs (xxx0): DAX enabled. Warning: EXPERIMENTAL, use at your own risk
[ 2917.044869] EXT4-fs (xxx0): mounting ext2 file system using the ext4 subsystem
...
...
[ 2917.045459] EXT4-fs (xxx0): mounted filesystem without journal. Opts: dax

which subsequently results in failure of fallocate, as the ext2 is not supported fos ext2.

any suggestions/solution would be appreciated.


Solution

  • Provide the type as ext4 while mounting. Or else it will take default type (or) type mentioned in /etc/fstab.

    # mount -o dax -t ext4 /dev/xxx0 /mnt/ext4-xxx0