So you should've commented out sda5
Can you locate the 2 fstab's?

2014-09-08
EDDY1,

(1) Grub-rescue shows the following partitions:
(hd0), (hd0,msdos7), (hd0,msdos6), (hd0,msdos5), (fd0).

I think they respectively correspond to /dev/sda, /dev/sda7, /dev/sda6, /dev/sd5, and the floopy drive.

Interestingly enough, /dev/sda2, the Ubuntu partition is not shown. Thus there's nothing I can do here.

(2) When I use Boot Repair in an attempt to fix my grub-rescue problem, it keeps reminding me to close all software package managers. I don't remember seeing this reminder before. I did my best to close whatever applications I saw. In short Boot Repair has not been helpful.

julianvb

sda2 is the Extended partition that sda5, sda6 & sda7 reside on.
Boot repair is not it you need to re-edit your /etc/fstab & it will boot.

1 members found this post helpful.

EDDY1,

My /etc/fstab file now looks as follows.
overlayfs / overlayfs rw 0 0
tmpfs /tmp tmpfs nosuid,nodev 0 0
/dev/sda6 swap swap defaults 0 0

The partiton I deleted was named /dev/sda6 and is now /dev/sda7.
(1) Can I add edit /etc/fstab by adding the following 3 lines to the end as below? (The UUIDs come from blkid)
(2) Do I need to change or remove the old /dev/sda6 line?
(3) How do I test the modified file?

/dev/sda5 UUID="24239e68-00ab-4cab-8cc1-c7f1f421e991" TYPE="ext2"
/dev/sda6 UUID="8816c492-5934-4303-a241-bd3dd5be005d" TYPE="swap"
/dev/sda7: UUID="c6a171de-d531-4965-9edb-018122283eef" TYPE="ext4"

julianvb

Did you delete or edit it out of fstab?

EDDY1,
This is what I've just put in /etc/fstab via my Linux Mint 17 Live CD as a first step. I am omitting the Mint 17 entry for now for simplicity.

(1) Please tell me if it looks correct.
(2) How do I set up an entry for a USB stick or USB HD in /etc/fstab?

Thanks for your help and patience.

julianvb
------------------------------------------------
# 2014-09-08 created
# Partition created for previous Mint 17
# UUID="24239e68-00a6-4cab-8cc1-c7f1f4212991"
# Swap partiton at /dev/sda6
UUID="8816c492-5934-4303-a241-6d3dd5be005d" none swap sw 0 0
# Ext4 partition at /dev/sda7
UUID="c6a171de-d531-4965-9edb-018122283eef" / ext4 error=remount-ro 0 0

Did you update-grub

I didn't before I saw your latest message, and I subsequently got the following error from Linux Mint 17 Live CD after entering 'sudo grub-install /dev/sda' or 'sudo update-grub'.

/usr/sbin/grub-probe:error: failed to get canonical path of 'cow'.

julianvb

Then you obviously need all of your entries in fstab. You may have to run

EDDY1,

I've just run 'sudo blkid' and then 'sudo update-grub'. The same 'cow' error re-appeared. Here's the blkid output.

Question 1: How can I check whether my /etc/fstab file contains errors?

Question 2: What does "failed to get canonical path of 'cow'" mean?

julianvb
------------------------------------------------
Output of 'sudo blkid'.

/dev/loop0: TYPE="squashfs"
/dev/sda5: UUID="24239e68-00a6-4ca6-8cc1-c7f1f421e991" TYPE="ext2"
/dev/sda6: UUID="8816c492-5934-4303-a241-bd3dd5be005d" TYPE="swap"
/dev/sda7: UUID="c6a171de-d531-4965-9edb-018122283eef" TYPE="ext4"
/dev/sr0: LABEL="Linux Mint 17 MATE 32-bit" TYPE="iso9660"
/dev/sdb1: LABEL="Elements" UUID="4E1AEA7B1AEA6007" TYPE="ntfs"

-----------------------------------------------------------------
The latest version of my /etc/fstab is listed below.

# 2014-09-08 created
## mint 17 partition at /dev/sda5
# UUID="24239e68-00a6-4cab-8cc1-c7f1f4212991"
## swap partiton at /dev/sda6
UUID="8816c492-5934-4303-a241-6d3dd5be005d" none swap sw 0 0
## ext4 partition at /dev/sda7
UUID="c6a171de-d531-4965-9edb-018122283eef" / ext4 errors=remount-ro 0 1

Post #19 shows the 3 UUID's that were in your fstab, your last post has a whole lot more than that but those entries are there.
Another thing is sda5 is about 1.5 GIGS & sa6 is abut 45GIGS I would say that you need them both.

EDDY1,

I've just revised /etc/fstab to restore the proc line and to include the ext2 /dev/sda5 mint17 partition. I'm not sure if the mint17 line is specified correctly.

The new /etc/stab file doesn't fix the 'cow' error after I enter 'sudo update-grub'.

# 2014-09-09 revised -- /etc/fstab file
##
## proc line
proc /proc proc nodev,noexec,nosuid 0 0
## mint 17 partition at /dev/sda5
UUID="24239e68-00a6-4cab-8cc1-c7f1f4212991" none ext2 errors=remount-ro 0 1
## swap partiton at /dev/sda6
UUID="8816c492-5934-4303-a241-6d3dd5be005d" none swap sw 0 0
## ext4 partition at /dev/sda7
UUID="c6a171de-d531-4965-9edb-018122283eef" / ext4 errors=remount-ro 0 1

EDDY1,

I was able to mount /dev/sd5 manually, which is known as (hd0,msdos5) to grub-rescue. Its directory /media/sda5 shows the two vital files initrd.img and vmlinuz but I am unable to load these these two files into grub via the grub-rescue prompt. Can you help me? I think this is the place for me to revive Ubuntu 12.04.

In other words, I am not familiar with grub-rescue at all.

Thanks again.

julianvb

2014-09-09 Reminder:2014-09-09 Reminder:

Even though I've finally achieved my objective (much to my subsequent regret). As someone had warned me, one should be very careful when one embarks on deleting a logical partition. The method I used is indicated in post #13. I hereby close my current question and open a new one to address how to use grub-rescue to fix a broken Ubuntu partition table.

julianvb

I don't know what you orignally had on sda5 but, if that was the partition on which you tried to install Mint I can see why it failed. It was mentioned above that it is a 1.5GB partition which is way to small for even a minimal install of Mint. Your original post shows swap on sda7 but in post #9, when you post your fstab file, it shows that it was on sda5 during installation. Your uuids keep changing which I expect to happen if you delete a partition and create a new one whether it is swap or another type. When you delete a logical partition, any logical partition with a higher number will also change.