I have a hard drive with ubuntu 14 installed. The whole disk is encrypted. My default users home directory is encrypted as well. Lately, after a system crash, I am presented with a busybox (initramfs) on startup. When I chose to start in recovery mode, I can grasp several error messages like " ... Failed to read block at offset xyz ...".
I searched and found this Q&A: Boot drops to a (initramfs) prompts/busybox
I booted from a CD and followed the instructions. However I am only able to do ...
sudo dumpe2fs /dev/sda1
... and then continue to check and repair superblocks on /dev/sda1 .
If I try ...
sudo dumpe2fs /dev/sda2
... i get the following error message:
dumpe2fs: Attempted to read block from filesystem resulted
in short read while trying to open /dev/sda2
Couldn't find valid filesystem superblock.
gparted shows the partitioning and file systems of the drive as follows:
partition file system size used unused flags
-------------------------------------------------------------
/dev/sda1 ext2 243M 210M 32M boot
/dev/sda2 extended 465G - - -
/dev/sda5!!crypt-luks 465G - - -
unallocated unallocated 1M - - -
The warning (!!) at sda5 says "Linux Unified Key Setup encryption is not yet supported".
If I try ...
sudo dumpe2fs /dev/sda5
... it returns this error message:
dumpe2fs: Bad magic number in super-block while trying to open /dev/sda5
Couldn't find valid filesystem superblock.
Mounting and rw-accessing sda1 works without error.
Any clues what is the cause and how i can repair, mount and decrypt the filesystem to boot normaly or at least to recover the data?
The given solution has missed some commands that you need to decrypt the file system and access it. Here's the full solution
Boot from Ubuntu USB
cryptsetup luksOpen /dev/rawdevice somename
sck /dev/mapper/somename
Get backup superblock:
sudo dumpe2fs /dev/mapper/ubuntu--vg-root | grep superblock
Fix:
sudo fsck -b 32768 /dev/mapper/ubuntu--vg-root -y
Verify:
mkdir /a
sudo mount /dev/mapper/ubuntu--vg-root /a
This worked for me:
Boot from Ubuntu USB
get backup superblock:
sudo dumpe2fs /dev/mapper/ubuntu--vg-root | grep superblock
fix:
sudo fsck -b 32768 /dev/mapper/ubuntu--vg-root -y
verify
mkdir /a
sudo mount /dev/mapper/ubuntu--vg-root /a
I used following links as source:
https://askubuntu.com/questions/137655/boot-drops-to-a-initramfs-prompts-busybox
https://serverfault.com/questions/375090/using-fsck-to-check-and-repair-luks-encrypted-disk
Related
This is all done as the root user.
The script for backups at /usr/share/perl5/PVE/VZDump/LXC.pm sets a default mount point
my $default_mount_point = "/mnt/vzsnap0";
But regardless of whether I use the GUI or the command line I get the following error:
ERROR: Backup of VM 103 failed - mkdir /mnt/vzsnap0:
Permission denied at /usr/share/perl5/PVE/VZDump/LXC.pm line 161.
And lines 160 - 161 in that script is:
my $rootdir = $default_mount_point;
mkpath $rootdir;
After the installation before I created any images or did any backups I setup two things.
(1) SSHFS mount for /mnt/backups
(2) Added all other drives as Linux LVM
What I did for the drive addition is as simple as:
pvcreate /dev/sdb1
pvcreate /dev/sdc1
pvcreate /dev/sdd1
pvcreate /dev/sde1
vgextend pve /dev/sdb1
vgextend pve /dev/sdc1
vgextend pve /dev/sdd1
vgextend pve /dev/sde1
lvextend pve/data /dev/sdb1
lvextend pve/data /dev/sdc1
lvextend pve/data /dev/sdd1
lvextend pve/data /dev/sde1
For the SSHFS instructions see my blog post on it: https://6ftdan.com/allyourdev/2018/02/04/proxmox-a-vm-server-for-your-home/
Here are filesystem directory permission related files and details.
cat /etc/fstab
# <file system> <mount point> <type> <options> <dump> <pass>
/dev/pve/root / ext4 errors=remount-ro 0 1
/dev/pve/swap none swap sw 0 0
proc /proc proc defaults 0 0
df -h
Filesystem Size Used Avail Use% Mounted on
udev 7.8G 0 7.8G 0% /dev
tmpfs 1.6G 9.0M 1.6G 1% /run
/dev/mapper/pve-root 37G 8.0G 27G 24% /
tmpfs 7.9G 43M 7.8G 1% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 7.9G 0 7.9G 0% /sys/fs/cgroup
/dev/fuse 30M 20K 30M 1% /etc/pve
sshfs#10.0.0.10:/mnt/raid/proxmox_backup 1.4T 725G 672G 52% /mnt/backups
tmpfs 1.6G 0 1.6G 0% /run/user/0
ls -dla /mnt
drwxr-xr-x 3 root root 0 Aug 12 20:10 /mnt
ls /mnt
backups
ls -dla /mnt/backups
drwxr-xr-x 1 1001 1002 80 Aug 12 20:40 /mnt/backups
The command that I desire to succeed is:
vzdump 103 --compress lzo --node ProxMox --storage backup --remove 0 --mode snapshot
For the record the container image is only 8GB in size.
Cloning containers does work and snapshots work.
Q & A
Q) How are you running the perl script?
A) Through the GUI you click on Backup now, then select your storage (I have backups and local and the both produce this error), then select the state of the container (Snapshot, Suspend, Stop each produce the same error), then compression type (none, LZO, and gzip each produce the same error). Once all that is set you click Backup and get the following output.
INFO: starting new backup job: vzdump 103 --node ProxMox --mode snapshot --compress lzo --storage backups --remove 0
INFO: Starting Backup of VM 103 (lxc)
INFO: Backup started at 2019-08-18 16:21:11
INFO: status = stopped
INFO: backup mode: stop
INFO: ionice priority: 7
INFO: CT Name: Passport
ERROR: Backup of VM 103 failed - mkdir /mnt/vzsnap0: Permission denied at /usr/share/perl5/PVE/VZDump/LXC.pm line 161.
INFO: Failed at 2019-08-18 16:21:11
INFO: Backup job finished with errors
TASK ERROR: job errors
From this you can see that the command is vzdump 103 --node ProxMox --mode snapshot --compress lzo --storage backups --remove 0 . I've also tried logging in with a SSH shell and running this command and get the same error.
Q) It could be that the directory's "immutable" attribute is set. Try lsattr / and see if /mnt has the lower-case "i" attribute set to it.
A) root#ProxMox:~# lsattr /
--------------e---- /tmp
--------------e---- /opt
--------------e---- /boot
lsattr: Inappropriate ioctl for device While reading flags on /sys
--------------e---- /lost+found
lsattr: Operation not supported While reading flags on /sbin
--------------e---- /media
--------------e---- /etc
--------------e---- /srv
--------------e---- /usr
lsattr: Operation not supported While reading flags on /libx32
lsattr: Operation not supported While reading flags on /bin
lsattr: Operation not supported While reading flags on /lib
lsattr: Inappropriate ioctl for device While reading flags on /proc
--------------e---- /root
--------------e---- /var
--------------e---- /home
lsattr: Inappropriate ioctl for device While reading flags on /dev
lsattr: Inappropriate ioctl for device While reading flags on /mnt
lsattr: Operation not supported While reading flags on /lib32
lsattr: Operation not supported While reading flags on /lib64
lsattr: Inappropriate ioctl for device While reading flags on /run
Q) Can you manually created /mnt/vzsnap0 without any issues?
A) root#ProxMox:~# mkdir /mnt/vzsnap0
mkdir: cannot create directory ‘/mnt/vzsnap0’: Permission denied
Q) Can you replicate it in a clean VM ?
A) I don't know. I don't have an extra system to try it on and I need the container's I have on it. Trying it within a VM in ProxMox… I'm not sure. I suppose I could try but I'd really rather not have to just yet. Maybe if all else fails.
Q) If you look at drwxr-xr-x 1 1001 1002 80 Aug 12 20:40 /mnt/backups, it looks like there are is a user with id 1001 which has access to the backups, so not even root will be able to write. You need to check why it is 1001 and which group is represented by 1002. Then you can add your root as well as the user under which the GUI runs to the group with id 1002.
A) I have no problem writing to the /mnt/backups directory. Just now did a cd /mnt/backups; mkdir test and that was successful.
From the message
mkdir /mnt/vzsnap0: Permission denied
it is obvious the problem is the permissions for /mnt directory.
It could be that the directory `s "immutable" attribute is set.
Try lsattr / and see if /mnt has the lower-case "i" attribute set to it.
As a reference:
The lower-case i in lsattr output indicates that the file or directory is set as immutable: even root must clear this attribute first before making any changes to it. With root access, you should be able to remove this with chattr -i /mnt, but there is probably a reason why this was done in the first place; you should find out what the reason was and whether or not it's still applicable before removing it. There may be security implications.
So, if this is the case, try:
chattr -i /mnt
to remove it.
References
lsattr output
According to inode flags—attributes manual page:
FS_IMMUTABLE_FL 'i':
The file is immutable: no changes are permitted to the file
contents or metadata (permissions, timestamps, ownership, link
count and so on). (This restriction applies even to the supe‐
ruser.) Only a privileged process (CAP_LINUX_IMMUTABLE) can
set or clear this attribute.
As long as the bounty is still up I'll give it to a legitimate answer that fixes the problem described here.
What I'm writing here for you all is a work around I've thought of which works. Note, it is very slow.
Since I am able to write to the /mnt/backups directory, which exists on another system on the network, I went ahead and changed the Perl script to point to /mnt/backups/vzsnap0 instead of /mnt/vzsnap0.
Bounty remains for anyone who can get the /mnt directory to work for the mount path to successfully mount vzsnap0 for the backup script..
1)
Perhaps your "/mnt/vzsnap0" is mounted as read only?
It may tell from your:
/dev/pve/root / ext4 errors=remount-ro 0 1
'errors=remount-ro' means in case of mistake remounting the partition like readonly. Perhaps this setting applies for your mounted filesystem as well.
Can you try remounting the drive as in the following link? https://askubuntu.com/questions/175739/how-do-i-remount-a-filesystem-as-read-write
And if that succeeds, manually create the directory afterwards?
2) If that didn't help:
https://www.linuxquestions.org/questions/linux-security-4/mkdir-throws-permission-denied-error-in-a-directoy-even-with-root-ownership-and-777-permission-4175424944/
There, someone remarked:
What is the filesystem for the partition that contains the directory.[?]
Double check the permissions of the directory, or whether it's a
symbolic link to another directory. If the directory is an NFS mount,
rootsquash can prevent writing by root.
Check for attributes (lsattr). Check for ACLs (getfacl). Check for
selinux restrictions. (ls -Z)
If the filesystem is corrupt, it might be initially mounted RW but
when you try to write to a bad area, change to RO.
Great, turns out this is a pretty long-standing issue with Ubuntu Make which is faced by many people.
I saw a workaround mentioned by an Ubuntu Developer in the above link.
Just follow the below steps:
sudo -s
unset SUDO_UID
unset SUDO_GID
Then run umake to install your application as normal.
you should now be able to install to any directory you want. Works flawlessly for me.
try ls laZ /mnt to review the security context, in case SE Linux is enabled. relabeling might be required then. errors=remount-ro should also be investigated (however, it is rather unlikely lsattr would fail, unless the /mnt inode itself is corrupted). Creating a new directory inode for these mount-points might be worth a try; if it works, one can swap them.
Just change /mnt/backups to /mnt/sshfs/backups
And the vzdump will work.
I have an Amazon EC2 instance (Ubuntu 12.04) to which I have attached two 250 GB volumes. Inadvertently, the volumes got unmounted. When I tried mounting them again, with the following command,
sudo mount /dev/xvdg /data
this is the error I get :
mount: /dev/xvdg already mounted or /data busy
Then, I tried un-mounting it as follows :
umount /dev/xvdg but it tells me that the volume is not mounted.
umount: /dev/xvdg is not mounted (according to mtab)
I tried lsof to check for any locks but there weren't any.
The lsblk output is as below :
Any help will be appreciated. What do I need to do to mount the volumes back without losing the data on them?
Ok, figured it out. Thanks #Petesh and #mootmoot for pushing me in the right direction. I was trying to mount single volumes instead of a RAID 0 array. The /dev/md127 device was running so I stopped it first with the following command :
sudo mdadm --stop /dev/md127
Then I assembled the RAID 0 array :
sudo mdadm --assemble --uuid <RAID array UUID here> /dev/md0
Once the /dev/md0 array became active, I mounted it on /data.
Try umount /dev/xvdg* and umount /data and then
mount /dev/xvdg1 /data
I don't have much experience with Linux and mounting/unmounting things. I'm using Amazon AWS, have booting up EC2 with Ubuntu image, and have attached a new EBS volume to the EC2. From the dashboard, I can see that the volume is attached to :/dev/sda1.
Now, I see from this guide from Amazon that the path will likely be changed by the kernel. So it's most likely that my /dev/sda1 device will be mounted on, maybe, /dev/xvda1.
So I logged in using terminal. I do ls /dev/ and I indeed see xvda1 on there. But I also see xvda. Now I want to format the device. But I don't know if the unformatted device is attached to xvda1 or xvda. I cannot list the content of /dev/xvda1 and /dev/xvda (it says ls: cannot access /dev/xvda1/: Not a directory). I guess I have to format it first.
I tried to format using sudo mkfs.ext4 /dev/xvda1. It says: /dev/xvda1 is mounted; will not make a filesystem here!.
I tried to format using sudo mkfs.ext4 /dev/xvda. It says: /dev/xvda is apparently in use by the system; will not make a filesystem here!
How can I format the volume?
EDIT:
The result of lsblk command:
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
xvda 202:0 0 8G 0 disk
`-xvda1 202:1 0 8G 0 part /
I then tried to use the command sudo mkfs -t ext4 /dev/xvda, but the same error message appears: /dev/xvda is apparently in use by the system; will not make a filesystem here!
When I tried to use the command mount /dev/xvda /webserver, error message appears: mount: /dev/xvda already mounted or /webserver busy. Some website indicate that this also probably because a corrupted or unformatted file system. So I guess I have to be able to format it first before able to mount it.
First of all you are trying to format /dev/xvda1, which is root device. Why ??
Second if you have added a new EBS, then follow below steps.
List Block Device's
This will give you list of block device attached to your EC2 which will look like
[ec2-user ~]$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
xvdf 202:80 0 100G 0 disk
xvda1 202:1 0 8G 0 disk /
Out of this xvda1 is the / (root) and xvdf is the one that you need to format and mount ( for the new EBS)
Format Device
sudo mkfs -t ext4 device_name # device_name is xvdf here
Create a Mount Point
sudo mkdir /mount_point
Mount the Volume
sudo mount device_name mount_point # here device_name is /dev/xvdf
Make an entry in /etc/fstab
device_name mount_point file_system_type fs_mntops fs_freq fs_passno
Execute
sudo mount -a
This will read your /etc/fstab file and if it's OK. it will mount the EBS to mount_point
I was trying to execute qemu while following the qemu/linaro tutorial,
https://developer.mozilla.org/en-US/docs/Mozilla/Developer_guide/Virtual_ARM_Linux_environment
I was executing the command,
sudo mount -o loop,offset=106496 -t auto vexpress.img /mnt/tmp
mount: you must specify the filesystem type
so i did fdisk on the img file and got the following,
Device Boot Start End Blocks Id System
vexpress.img1 * 63 106494 53216 e W95 FAT16 (LBA)
vexpress.img2 106496 6291455 3092480 83 Linux
The filesystem is Linux according to the fdisk command. But I get error,
sudo mount -o loop,offset=106496 -t Linux vexpress.img /mnt/tmp
mount: unknown filesystem type 'Linux'
Kindly help.
You correctly decide to mount the particular partition by specifying its offset but the offset parameter is in bytes and fdisk shows the offset in blocks (the block size is shown before the partition list --- usually 512). For the block size 512 the command would be:
sudo mount -o loop,offset=$((106496*512)) -t auto vexpress.img /mnt/tmp
If the automatic file system type detection does not still work there is another problem. Linux is not really a file system type. In the partition table it is a collective type used for multiple possible particular file systems. For mount you must specify the particular file system. In Linux you can list the supported ones by cat /proc/filesystems.
I use following command to mount "/dev/sdb1" to "/storage" directory:
mount -t ext3 /dev/sdb1 /storage
After run above command, I can use "df -h" can see it:
/dev/sdb1 147G 188M 140G 1% /storage
But after i restart the server, it disappear, and i have to run mount command again.
Is there a command that can keep the mount even if i restart the server?
Add the following line to your /etc/fstab file:
# device name mount point fs-type options dump-freq pass-num
/dev/sdb1 /storage ext3 defaults 0 0
You can run (as root):
echo "/dev/sdb1 /storage ext3 defaults 0 0" >> /etc/fstab
You need to add relevant information to /etc/fstab.