Peter Kjellstr?m wrote:
> On Monday 23 January 2006 16:46, Plant, Dean wrote:
>> I need to downgrade a system from Centos x4.2 to v3.6 (x86) due to
>> performance problems with Arkeia Network Backup and AIT-4 tape
>> drives. The backup database is stored on a v4.2 created ext3
>> partition. When accessing this partition after the downgrade, Centos
>> complains on boot that
>>
>> fsck.ext3: Filesystem has unsupported feature(s) (/dev/sda5)
>> *fsck: Get a newer version of e2fsck! [fail]
>
> you can list the features with the command "tune2fs -l /dev/sda5" and
> toggle features too (read the man page). It's most likely the
> dir_index feature...
>
Thanks Peter for the prod in the right direction.
A v4 filesystem shows these features
# tune2fs -l /dev/sda1 | grep features
Filesystem features: has_journal ext_attr resize_inode dir_index filetype needs_recovery sparse_super large_file
A v3 filesystem has these features
# tune2fs -l /dev/sda5 | grep features
Filesystem features: has_journal filetype needs_recovery sparse_super
Tunes2fs from v4.2 can be used to remove "has_journal filetype dir_index sparse_super"
Booted into rescue mode with a v4.2 cd and removed dir_index but the v3.6 OS still complained.
After finding this link https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=145307 which references problems with ghost and v4 ext3 partitions I used debugfs to remove some of the other 4.2 specific features.
# debugfs -w /dev/sda5 -R "features ^resize_inode ^ext_attr"
# fsck -y /dev/sda5
The v3.6 OS now boots correctly.
Dean.
>>
>> If I comment the partition out of /etc/fstab the machine boots as
>> normal and I can manually mount the filesystem.
>>
>> My questions are:
>>
>> If I use the v4.2 ext3 filesystem on v3.6 I am likely to corrupt the
>> data?
>
> I don't think you're running any risk of corrupting your data.
>
> /Peter
>
>> And what is the best way fix this problem? Do as it says and try
>> and upgrade e2fsck or is there a better fix?
>>
>> Thanks
>>
>> Dean.
