invalid filesystem - ext4

[wa4chq]

Hi-
My hard drive is partitioned with windows, zenwalk and mint9 flux. Mint was the last installed and I was able to boot into all three. I have been enjoying using Mint. Very nice. But, I decided to get rid of Zen and install Slackware 12.1 in its place..../dev/sda3 (mint is on /dev/sda4). Everything went fine with the Slack install until reboot time. Slack uses lilo and when I rebooted I saw windows, but only one linux....where was my other linux, Mint flux? I did
fdisk /dev/hda, p and saw that /dev/sda4 (slack labels it as /dev/hda4) was still there but when I tried to see if I could mount it, I get an error message saying "invalid filesystem ext4". And then thought I could use the Mint disk and boot to /dev/sda4 but I don't see any form of rescue mode. I tried knoppix and I can't even mount that partition. (Is file extention ext4 which was used when installing Mint new? Slack 12.1 is not so new and I seem to remember using ext3 all of the time.)

I guess Mint uses grub and maybe that is part of the problem. Anyway, I don't mind scrapping Slack (I have it installed on another HD) if there is no other way to fix it, but the main thing is I would like to save Mint if possible but don't know how to repair the boot loader, if that is the correct term.

Thanks

[oobetimer]

Boot using Super Grub2 Disk, and install Mint´s grub to the MBR and update grub

sudo blkid

...if the HD is sda

sudo grub-install /dev/sda

sudo os-prober

sudo update-grub


http://www.supergrubdisk.org/super-grub2-disk/

[wa4chq]

Hey, that looks very promising. Thank you very much for the info!

[wa4chq]

I downloaded the SuperGrup2 image, burned it to a disk and was good to go in minutes. I haven't made any hard changes yet, but will.
Thanks again.