resized partition on install, now can't access data

[looksalota]

When I installed 11.04 I had data in a partition I wanted to keep. (backed up to other computer) This is on a 500gb drive. I reduced the partition to 350gb, and changed from ext3 to ext4, and after install in file manager the properties showed less data, and when I try to access the partition the only thing I see is "lost + found".
Have I hosed the data? Should I just format the whole drive and start over?

[james147]

If you change the partition type in the installer for the drive it formats the drive as that type... losing all the data.

There is normally no simple way to change from one filesystem type to another, but with extX you can mount them as other version of ext (ie you can mount a ext3 partition as ext4) to gain/lose some of the benefits of the later version. This does not however convert the filesystem to the new version (the filesystem its not actually changed, just the driver that access it).

The only filesystem that I have seen that you can do this with is extX to btrfs (btrfs has a conversion and reversion program) however the installer likely doesn't know about this so it will just do a reformat.

Best option is to restore from backups the data onto the new drive/partition, there should be no need to reinstall again if the disks are already partitions how you want them.