Peter Kjellström 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.