How To Remount Root Partition On System Booted From External Usb Drive

Hi,

I have problems mounting my second drive at boot automatically.
(sorry i am a noob)

When i use the mount command, it works fine.
Code:

mount -t ext3 /dev/sdb2 /mnt/HD/HD_b2

But when i try to add one if the following lines to /etc/fstab
It will not mount the drive at boot or with Code:

mount -a

, also fstab is empty afer reboot (normal??)

Code:

/dev/sdb2 /mnt/HD/HD_b2 ext3 defaults,errors=remount-ro 0 1

Code:

UUID=553afede-fa45-4cdc-9972-c0a9aa899509 /mnt/HD/HD_b2 ext3 errors=remount-ro 0 1

Code:

/dev/sdb2 /mnt/HD/HD_b2 ext3 rw 0 0

Code:

/dev/sdb2 /mnt/HD/HD_b2 ext3 defaults 0 1

output blkid:

Code:

/dev/sda1: UUID="e67e5c15-7b8b-9389-c311-e5d4c61326f9" TYPE="linux_raid_member"
/dev/sda2: UUID="09e0e365-0aa6-4214-b571-2bc6b027fd9f" TYPE="ext3"
/dev/sda4: UUID="64038414-136c-4939-bd14-9871a20290bd" TYPE="ext3"
/dev/sdb1: UUID="e67e5c15-7b8b-9389-c311-e5d4c61326f9" TYPE="linux_raid_member"
/dev/sdb2: UUID="553afede-fa45-4cdc-9972-c0a9aa899509" TYPE="ext3"
/dev/sdb4: UUID="bf594be6-ffb6-469d-a3a8-246be66a4d90" TYPE="ext2"

/etc/mtab:

Code:

rootfs / rootfs rw 0 0
/dev/root / ext2 rw,relatime,errors=continue 0 0
sysfs /sys sysfs rw,relatime 0 0
proc /proc proc rw,relatime 0 0
squash /usr/local/tmp ramfs rw,relatime,size=38m 0 0
/dev/loop0 /usr/local/modules squashfs ro,relatime 0 0
/dev/mtdblock5 /usr/local/config jffs2 rw,relatime 0 0
/dev/sda4 /mnt/HD_a4 ext3 rw,relatime,errors=continue,data=writeback 0 0
/dev/sdb4 /mnt/HD_b4 ext2 rw,relatime,errors=continue 0 0
none /proc/bus/usb usbfs rw,relatime 0 0
/dev/sda2 /mnt/HD/HD_a2 ext3 rw,relatime,errors=continue,user_xattr,data=writeb$
/dev/sdb2 /mnt/HD/HD_b2 ext3 rw,relatime,errors=continue,user_xattr,data=writeb$
/dev/sda2 /mnt/HD/HD_a2/squeeze/mnt/HD/HD_a2 ext3 rw,relatime,errors=continue,u$
/dev/root /mnt/HD/HD_a2/squeeze/mnt/root ext2 rw,relatime,errors=continue 0 0
/dev/root /mnt/HD/HD_a2/squeeze/dev ext2 rw,relatime,errors=continue 0 0
sysfs /mnt/HD/HD_a2/squeeze/sys sysfs rw,relatime 0 0
proc /mnt/HD/HD_a2/squeeze/proc proc rw,relatime 0 0

When mount command is used Code:

mount -t ext3 /dev/sdb2 /mnt/HD/HD_b2

The following line is added to mstab -->
Code:

/dev/sdb2 /mnt/HD/HD_b2 ext3 rw 0 0

I diont know what i am doing wrong, mount for HD_a2 works fine (other disk, worked at default), i hav e NAS DNS-325 where i installed Debian on. I used this tutorial to install debian.

The strange thing is, i had to reinstall my NAS, and befor it worked fine after i had installed debian 2 years ago, i just dont remeber how i fixed this.

I can't seem to mount a CD-R or DVD-R, doesn't matter if it is blank or not.
However, when I use a program such as Brasero, I am able to write to them. I cannot use dd to write to them.

This is the output of trying to mount/unmount.
Code:

root@delarocha-> mount /dev/sr0 /media/cd
mount: /dev/sr0 is write-protected, mounting read-only
mount: wrong fs type, bad option, bad superblock on /dev/sr0,
       missing codepage or helper program, or other error
       In some cases useful info is found in syslog - try
       dmesg | tail or so.

root@delarocha-> umount /dev/sr0
umount: /dev/sr0: not mounted
root@delarocha-> umount /media/cd
umount: /media/cd: not mounted
root@delarocha-> umount /media/cdrom
umount: /media/cdrom: not mounted

dmesg | tail
Code:

root@delarocha-> dmesg | tail
[ 1536.299777] sr 1:0:0:0: [sr0]  
[ 1536.299804] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[ 1536.299809] sr 1:0:0:0: [sr0]  
[ 1536.299814] Sense Key : Illegal Request [current] 
[ 1536.299820] sr 1:0:0:0: [sr0]  
[ 1536.299824] Add. Sense: Logical block address out of range
[ 1536.299829] sr 1:0:0:0: [sr0] CDB: 
[ 1536.299832] Read(10): 28 00 00 00 00 00 00 00 01 00
[ 1536.299846] end_request: I/O error, dev sr0, sector 0
[ 1536.299915] EXT4-fs (sr0): unable to read superblock

I don't think it can be anything wrong with the disk, since it is a untouched disk.
Note: The results of everything(apart from dmesg I would assume), are the same for a CD-R and DVD-R

This is what I get while trying to dd a .iso and .mp4, respectively.

Code:

web@delarocha-> dd if=/dev/sr0 of=~/Downloads/xubuntu-14.04.1-desktop-amd64.iso
0+0 records in
0+0 records out
0 bytes (0 B) copied, 0.000377316 s, 0.0 kB/s

Code:

web@delarocha-> dd if=/dev/sr0 of=~/Videos/The\ Hobbit/The\ Hobbit\ The\ Desolation\ of\ Smaug.mp4
0+0 records in
0+0 records out
0 bytes (0 B) copied, 0.000377179 s, 0.0 kB/s

uname -a
Code:

Linux delarocha 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt2-1 (2014-12-08) x86_64 GNU/Linux

When I used lsblk when I close the disk tray, it shows it mounted.
Code:

sr0                     11:0    1     2K  0 rom

But after I use the dd command to write the .iso, it disappears.

Here is my /etc/fstab
Code:

# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
/dev/mapper/delarocha-root /               ext4    errors=remount-ro 0       1
# /boot was on /dev/sda1 during installation
UUID=5bbedec0-6e3d-4185-91e0-292a72585908 /boot           ext2    defaults        0       2
/dev/mapper/delarocha-swap_1 none            swap    sw              0       0
/dev/sr0        /media/cdrom0   udf,iso9660 user,noauto     0       0
/dev/sdb1       /media/usb0     auto    rw,user,noauto  0       0

I have also tried replacing /dev/sr0 in the above commands with /media/cdrom0.

Using a Kingston 4GB datatraveler for drive creation
Created using amd64 1.1.0a of the Kali ISO verified from Kali.org
Drive created using Ubuntu 14.04 on a Dell Latitude E5500

dd seems to create the drive with no errors. The drive boots to the error. Hard reboot into Ubuntu to search for solution has led me to a long series of issues that I have been trying to correct.

A possible fix for the failed to load error is to copy the file to the root of the USB drive (/dev/sdb1). Drive is created with a hidden HPFS/ NTFS fs. 0x17. Changed FS to HPFS/NTS (0x07). Drive now mounts, but when attempting to copy onto drive, I get an error that the file system is read only.

I try to correct the issue using nautilus and the properties menu. It does not allow me to change the view only to read/write even though it shows me as the owner.

I think maybe a command line thing would work, or who knows what else. Maybe an fstab entry? I am continuing to search the web, and hope to work this out.

Any help would be appreciated.

Hi all. My first time post and very new to linux.
I am using linux Mint Debian version.

My goal is to auto mount 2 external harddrives (Each hard drive is 2TB) attached to the 2 usb ports on my asus wireless router model rt-n56r.

I have succeeded in auto mounting my first drive HDD1 by configuring fstab file:

//192.168.1.1/HDD1 /media/public cifs username=**,password=**,rw,nounix,iocharset=utf8,file_mode=0777,dir_mode=0777 0 0

At boot this partition is mounted without issue.

In attempting to mount the second hard drive HDD2 I added another entry in fstab as follows:

//192.168.1.1/HDD2 /media/public cifs username=**,password=**,rw,nounix,iocharset=utf8,file_mode=0777,dir_mode=0777 0 0

It appears that both HDD1 and HDD2 mount however, when entering the partition only files and directories of the second hard drive appear.

So I changed the mount point in the second hard drive to reflect /media1/public1 and after the configuration neither hard drive appears to have mounted.

I tried using UUID instead of path to partition but cannot get even 1 attached hard drive to mount.

I appreciate in advance the help and assistance to my query.

I am installing VirtualBox on Centos per http://www.digitesters.com/centos-in...adless-system/, and I don't understand the very end. Seems like Line 5 is not needed as it is already done on Line 4, right?

Code:

# mkdir /data/virtual_machines/vbox/vbusbfs
# chown vboxuser.vboxusers /data/virtual_machines/vbox/vbusbfs
# chmod 775 /data/virtual_machines/vbox/vbusbfs
# echo "none /data/virtual_machines/vbox/vbusbfs usbfs rw,devgid=$(awk -F : '/vboxusers/ {print $3}' /etc/group),devmode=664 0 0" >> /etc/fstab
# echo "none /data/virtual_machines/vbox/vbusbfs usbfs rw,devgid=$(awk -F : '/vboxusers/ {print $3}' /etc/group),devmode=664 0 0" >> /etc/fstab
# mount -a

I executed the above script (except didn't execute Line 5, and my user:group is vbox:vbox and not vboxuser.vboxusers, and the folder is at /home/vbox and not /data/virtual_machines/vbox), and the following was added to /etc/fstab. Please explain what Line 4 did and what the below line in my fstab file means.
Code:

none /home/vbox/vbusbfs usbfs rw,devgid=496
504,devmode=664 0 0

I then executed mount -a, and got the following response. The part about /var/www/main/ayb_resources and /var/www/main/ayb_cache does not exist is probably some old stuff which I can get rid of, but I am particularly interested in "mount point 0 does not exist" as it seems to be related to the above.

Code:

[root@devserver vbox]# mount -a
mount: special device /var/www/main/ayb_resources does not exist
mount: special device /var/www/main/ayb_cache does not exist
mount: mount point 0 does not exist
[root@devserver vbox]#

My total fstab file is as follows:

Code:

[root@devserver vbox]# cat /etc/fstab
#
# /etc/fstab
# Created by anaconda on Sat Apr 19 05:57:56 2014
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
/dev/mapper/VolGroup-lv_root /                       ext4    defaults        1 1
UUID=xxx-xxx-xxx-xxx-xxx /boot                   ext4    defaults        1 2
/dev/mapper/VolGroup-lv_home  /home                  ext4    defaults        1 2
/dev/mapper/VolGroup-lv_mysql /var/lib/mysql         ext3    barrier=0       1 2
/dev/mapper/VolGroup-lv_swap swap                    swap    defaults        0 0
tmpfs                   /dev/shm                tmpfs   defaults        0 0
devpts                  /dev/pts                devpts  gid=5,mode=620  0 0
sysfs                   /sys                    sysfs   defaults        0 0
proc                    /proc                   proc    defaults        0 0
/home/public/lib /var/www/main_lib/ayb_application/lib none bind
/var/www/main/html /var/www/main_lib/html none bind
/var/www/main/ayb_resources /var/www/main_lib/ayb_resources none bind
/var/www/main/ayb_cache /var/www/main_lib/ayb_cache none bind
none /home/vbox/vbusbfs usbfs rw,devgid=496
504,devmode=664 0 0
[root@devserver vbox]# mount -a
mount: special device /var/www/main/ayb_resources does not exist
mount: special device /var/www/main/ayb_cache does not exist
mount: mount point 0 does not exist
[root@devserver vbox]#

am i right in saying that fstab only describes to the system what partitions should be mounted to what device (location) i know it can do a bit more than that...

but how do you get the system to mount file systems automatically at start up? is that a setting within fstab? under mount options...or is it a command that you need to type...or is it in another config file?

My attempts to back-up to an external hard disk finally met with apparent success but I cannot now mount the target drive.

To summarize:-
1. Installing a SATA hard disk, identical to my computer's main drive, in a USB 2.0 caddy and attaching this to the computer resulted in qualified recognition. 'fdisk' 'saw' both the main drive, as sda, and the USB drive, as sdb, respectively but initially noted that the latter, “... doesn't contain a valid partition table.” This was hardly surprising. At the point of first connection the external drive was essentially a 'bare metal' device, having had its data wiped. Nevertheless, 'fdisk' correctly reported its size, number of heads and cylinders, etc.
2. 'dmesg' also correctly identified the external disk as sdb, reporting its type and the USB port to which it is connected.
3. 'df' ignores the second hard drive, reporting only the main disk.
4. Attempts to clone/back-up the main disk to the external disk using the recommended tools EaseUS Todo back-up and RedoBackup, booting respectively from appropriate USB memory sticks, both failed. Neither utility was prepared to write to the external disk. EaseUS acknowledged the latter but crashed the whole computer when instructed to perform the clone. RedoBackup failed to recognize the external disk.
5. Then came the break-through. A bit more Net browsing led me to try the command 'dd if=/dev/sda of=/dev/sdb'. The main disk was bit-copied (cloned) to the external disk at roughly 20Gb per hour, meaning that my 80Gb disk was copied in just under 4 hours. Checking 'dd's resulting report showed what appeared to be a perfect copy.

So far, so good. I now have a back-up which, being identical to the main disk, should, I assume, be bootable. In the event of trouble with the main disk I should be able simply to exchange it for the external disk and carry on from the point at which I made my last back-up. I cannot, however, access and read the external disk. I assume that it must have a partition table and be mounted. The first requirement appears to have been resolved by the cloning operation. 'fdisk' reports no trouble with the partition table on the cloned external disk. It lists /dev/sb1 as the bootable Linux partition, /dev/sdb2 as the Extended partition and /dev/sdb5 as the Linux swap / Solaris partition, exactly mirroring the corresponding entries for the main, sda, drive.

My attempts to mount the external disk have all failed, however. I clearly do not understand the syntax of the mount command or have failed to meet some other requirement. 'mount' objected without hesitation to my early mistakes but “mount -t dev/sdb” was instantly accepted. No error messages or other output resulted and the command prompt was immediately redisplayed but 'mount' then failed to show that the external drive had been mounted. If I try something like 'mount -t /dev/sdb1 /mnt/xdisk', where xdisk is a directory I have been told to create, then I am presented with a prolix description of 'mount's syntax, most of which leaves me bewildered. 'mount' then once again confirms that sdb1 does not feature in the list of mounted devices.

Can someone offer any suggestions? I have read one or two of the other posts on this topic but none of the details match my problem too well and I did not understand some of the replies. If I try to add a line to /etc/fstab, for example, I find that I do not have a directory called 'fstab', only 'fstab.d' and that is empty.

I have roughly one year's experience with Linux Mint 13 which I chose because it so closely resembled Windows XP.

Booted my computer with 2 USB flash drives inserted. One of the drives turned out to be an MS-DOS boot drive. The PC booted in DOS and wiped out the partition table of the other flash drive with my data on it. This second (64Gb) drive had a single 64Gb type 83 (Linux) primary partition (ext4 file system).

Is there a way to recover the data that's on the second stick?

I've been told that all I have to do is repartition it exactly as it was and my data will be there. But I'd like to have advice from the pros here before I start messing with it.

For the time being, I dd-ed the entire stick, as is, onto a blank partition of my hard disk (dd if=/dev/sdb of=/dev/sda14). The process completed without errors but /dev/sda14 is unmountable for the moment.

Thanks for any help.

I recently bought a WD external hard drive for storing file of several types. Using gparted I made two partitions, one ntfs for windows files and an ext 4 for linux files. Strangely, I have complete access to ntfs partition from linux side of duel boot system, but do not have permission to access ext4 partition. My root password does not work when I use su to gain root access. It works fine on built in hard drive.

Linux Newbie here...running Ubuntu 14.04 LTS

Downloaded a couple of binaries/executables to the Downloads directory. ./command runs just fine but copying the binaries to /bin or /usr/bin says permission denied. I used chmol

After digging a bit more, realized that my FS is being mounted as read only!. Not sure why. /etc/fstab says UUID=8559f1a0-60e0-47e4-922d-9175f282fa8a / ext4 errors=remount-ro 0 1

Something is not right with the filesystem and I am not sure how to fix it.

Thanks
Raj