Sunday, January 15, 2017

Ubuntu 16.10 is not booting because of error stick: gfxboot.c32: not a COM32R image


When trying to boot Ubuntu 16.10 from USB stick, it fails to boot from following error


Missing parameter in configuration file. Keyword: path
gfxboot.c32: not a COM32R image
boot :

This error had been reported since the Ubuntu versions 14.04. Discussion regarding this can be found here.


Therefore as a solution for this issue, I figured out following workaround.


  1. Whenever this error is getting thrown during startup, press the TAB key
  2. Choose among options like live, live-install etc ... I chose the live option.
  3. Next press enter.
This will take into the live OS and from thereon wards, Ubuntu 16.10, can be installed using USB stick.

How to prepare bootable usb stick for Ubuntu 16.10


In this post I will explain to create a bootable USB disk to install Ubuntu 16.10.

Prerequisites


  • USB Flash disk with at least 2 GB free space.
  • Ubuntu 16.10 ISO image


Steps

Install gparted tool to enable formatting of the USB disk.
Install mksub tool to wipe out the first mega byte of file system and create a new a partition of
  same file system.

- Run Startup Disk Creator/USB Creator


  1. Insert the usb disk and run the Startup Disk Creator.
  2. Choose the image file and make sure to format the USB stick using usb creator's graphical user interface.

 


Once you click the right-most button, eventually it will create a bootable USB disk for Ubuntu 16.10.

Now as the final step after using usb stick for boot-able disk task, in order to restore usb disk to standard storage drive we can use the mksub-nox utility.

Monday, January 9, 2017

How to fix the ERROR 1698 (28000): Access denied for user 'root'@'localhost'


After upgrading from MySQL version 5.5 to 5.7, whenever I tried to log in to the database as non sudo user it throws following error. But I was able to log into the system as sudo user without any issues.



firzhan@firzhan-wso2:/etc/mysql$ mysql -u root -padmin 
mysql: [Warning] Using a password on the command line interface can be insecure.
ERROR 1698 (28000): Access denied for user 'root'@'localhost'


I followed following steps to do a quick fix

  • First connect to the mysql as sudo user.
  • Check the users presently available in the databases's user table.
  1. SELECT User,Host FROM mysql.user;
    +------------------+-----------+
    | User             | Host      |
    +------------------+-----------+
    | admin            | localhost |
    | root             |    *      |
    | root             | %         |
    | mysql.sys        | localhost |
    | root             | localhost |
  • Delete all the entries/accounts related to root user.
  • mysql> DROP USER 'root'@'localhost';
    Query OK, 0 rows affected (0,00 sec)
    
    mysql> DROP USER 'root'@'*';
    Query OK, 0 rows affected (0,00 sec)
    mysql> DROP USER '%';
    Query OK, 0 rows affected (0,00 sec)
  • Again insert an entry for root user in the table.
  • mysql> CREATE USER 'root'@'%' IDENTIFIED BY '';
    Query OK, 0 rows affected (0,00 sec)
  • Grant relevant permissions for that particular user of the database and make sure to flush the privileges.
  • mysql> GRANT ALL PRIVILEGES ON *.* TO 'root'@'%';
    Query OK, 0 rows affected (0,00 sec)
    
    mysql> FLUSH PRIVILEGES;
    Query OK, 0 rows affected (0,01 sec)
  • Exit and try to reconnect to the terminal without sudo.