Ubuntu: Ubuntu 12.04 on Amazon EC2: /dev/xvda1 will be checked for errors at next reboot?


I'm running the lastest Ubuntu 12.04 AMI (ami-a29943cb) from Canonical on Amazon EC2 and quite often when I log in I get the message:

*** /dev/xvda1 will be checked for errors at next reboot ***  

I have read a bunch of documentation on this and seem to understand that every so many reboots (around 37 see Mount count / Maximum mount count below) Ubuntu wants to check a disk for errors. I can see that by using dumpe2fs -h /dev/xvda1 (reference) to get information such as:

Last mounted on:          /  Filesystem UUID:          1ad27d06-4ecf-493d-bb19-4710c3caf924  Filesystem magic number:  0xEF53  Filesystem revision #:    1 (dynamic)  Filesystem features:      has_journal ext_attr resize_inode dir_index filetype needs_recovery extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize  Filesystem flags:         signed_directory_hash   Default mount options:    (none)  Filesystem state:         clean  Errors behavior:          Continue  Filesystem OS type:       Linux  Inode count:              524288  Block count:              2097152  Reserved block count:     104857  Free blocks:              1778055  Free inodes:              482659  First block:              0  Block size:               4096  Fragment size:            4096  Reserved GDT blocks:      511  Blocks per group:         32768  Fragments per group:      32768  Inodes per group:         8192  Inode blocks per group:   512  Flex block group size:    16  Filesystem created:       Tue Apr 24 03:07:48 2012  Last mount time:          Thu Nov  8 03:17:58 2012  Last write time:          Tue Apr 24 03:08:52 2012  Mount count:              3  Maximum mount count:      37  Last checked:             Tue Apr 24 03:07:48 2012  Check interval:           15552000 (6 months)  Next check after:         Sun Oct 21 03:07:48 2012  Lifetime writes:          2454 MB  Reserved blocks uid:      0 (user root)  Reserved blocks gid:      0 (group root)  First inode:              11  Inode size:           256  Required extra isize:     28  Desired extra isize:      28  Journal inode:            8  Default directory hash:   half_md4  Directory Hash Seed:      0a25e04c-6169-4d68-bfa6-a1acd8e39632  Journal backup:           inode blocks  Journal features:         journal_incompat_revoke  Journal size:             128M  Journal length:           32768  Journal sequence:         0x0000158b  Journal start:            1  

I've tried these things to get rid of the message and usually the badblocks is what does it for me:

Run this command and reboot:

sudo touch /forcefsck  

Run badblocks to check the disk:

badblocks /dev/sda1  

Edit /etc/fstab and change the last "0" which is the fs_passno column accordingly and then reboot:

The root filesystem should be specified with a fs_passno of 1, and other filesystems should have a fs_passno of 2.

I don't understand:

  1. If this is a virtual drive shouldn't it be less prone to errors?
  2. Was the image created with one of the flags set? If not what is triggering it?
  3. Why is fs_passno set to 0 on Amazon EC2 Ubuntu images? This is not the first one that is like this.


Why is fs_passno set to 0 on Amazon EC2 Ubuntu images?

If fsck were run on boot and found problems, then it might be sitting waiting for the answer to a prompt. However, since Amazon EC2 does not provide access to the console on an instance, there is no way that you could answer the prompt and the instance would become unusable.

Linked Q&A:


From Eric's linked Q&A, the short version is:

It is a bug on Ubuntu 11.04 and 12.04 ... which causes a file to be created with a future time stamp that contains that message.

The simplest solution to fix this bug is to delete the notification file:

sudo rm /var/lib/update-notifier/fsck-at-reboot  

Other ways to deal with it can be found in that Q&A.

Note:If u also have question or solution just comment us below or mail us on toontricks1994@gmail.com
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