Python3 connect to Microsof SQL Server

1. sudo apt-get install python3-pip
2. pip3 install pyodbc
3. sudo apt-get install unixodbc-dev
4. follow the Microsoft's documentations (ref: https://docs.microsoft.com/en-us/sql/connect/odbc/linux-mac/installing-the-microsoft-odbc-driver-for-sql-server?view=sql-server-ver15 )
4.a
sudo su

curl https://packages.microsoft.com/keys/microsoft.asc | apt-key add - 4.b curl https://packages.microsoft.com/config/ubuntu/18.04/prod.list > /etc/apt/sources.list.d/mssql-release.list
4.c sudo apt-get update
4.d sudo apt-get install msodbcsql17


Test connection with this code:

import pyodbcconn = pyodbc.connect("Driver={ODBC Driver 17 for SQL Server};" "Server=SERVER_IP;" "Database=DB_NAME;" "uid=DB_USERNAME;pwd=DB_PASSWORD;")conn.close()

Some error maybe occured:
> ModuleNotFoundError: No module named 'pyodbc' --> solution: pip3 install pyodbc

> pyodbc.Error: ('01000', "[01000] [unixODBC][Driver Manager]Can't open lib 'ODBC Driver 17 for SQL Server' : file not found (0) (SQLDriverConnect)") --> solution: sudo apt-get install msodbcsql17

* My machine ubuntu 18.04

How to start ubuntu in command line interface

I want to set my ubuntu PC to command line interface. I don't want to start the desktop manager.

1. Edit /etc/default/grub

2. Find this section:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""

3. change to:

GRUB_CMDLINE_LINUX_DEFAULT="text"
GRUB_CMDLINE_LINUX="3"

 4. run: sudo update-grub

5. Done. Every time we start the PC, it doesn't start the desktop manager automatically. If we want to start the desktop manager, run: sudo init 5


* My machine ubuntu 18.04

Linux command low level format

Warning!!! This command will destroy all data on your drive

This command is use to check bad sector on a hard disk.

dd if=/dev/zero of=/dev/sda1 bs=1024

Now we know that is a trouble at first 1 GB

Replacing hard disk on xenserver / linux software RAID

mark as failed disk :

    mdadm --manage /dev/md0 --fail /dev/sdb1 

remove the disk :

    mdadm --manage /dev/md0 --remove /dev/sdb1

change the physical drive, copy the partition, create the exact same partitioning as on/dev/sda :

    sfdisk -d /dev/sda | sfdisk /dev/sdb

add the new drive

    mdadm --manage /dev/md0 --add /dev/sdb1

done, check the progress :

    cat /etc/mdstat

references:

• https://www.howtoforge.com/replacing_hard_disks_in_a_raid1_array

Xenserver / linux software raid

I want my Storage Repository (SR) run under the software RAID (RAID1). My xenserver version 6.5. XenServer 6.5 do not load soft raid kernel modules on boot. To load soft raid manually run :

modprobe raid1

To load the soft raid module on boot, we can follow this steps : http://discussions.citrix.com/topic/360943-software-raid-mdadm-on-xenserver-65-unexpected-failure/?p=1855912

To build the RAID array :

 
mknod /dev/md1 b 9 1

mdadm --create /dev/md1 --level=1 --raid-devices=2 /dev/sdb1 /dev/sdc1

/dev/sdb1

and

/dev/sdc1

is using linux raid autodetect as the partition type. Use fdisk to create those partition.

To check the RAID building process :

cat /proc/mdstat

reference :

•  https://staff.ie.cuhk.edu.hk/~sfluk/wordpress/wp-content/uploads/2010/06/Software-RAID-on-XenServer.doc
• http://discussions.citrix.com/topic/360943-software-raid-mdadm-on-xenserver-65-unexpected-failure/?p=1855912