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lsb_release: command not found... : Linux/ Database Admin

Atikh Shaikh MongoDB, mysql, oracle, PostgreSQL No comments

As Database Admin, Linux Admin, or system admin, you must have come across this error or situation,

Here I was trying to see release details of the Linux operating system using the lsb_release command but it failed with the below error.

On seeing this error, I thought lsb_release was not installed on the server, so I tried to install using the yum command but it failed with the error "Error: Unable to find a match: lsb_release"

[root@localhost bin]# lsb_release

bash: lsb_release: command not found...

[root@localhost bin]# yum install lsb_release

Last metadata expiration check: 0:07:24 ago on Sat 30 Dec 2023 11:04:11 AM UTC.

No match for argument: lsb_release

Error: Unable to find a match: lsb_release

[root@localhost bin]#

So here is the trick, you need to identify which package provides this command using the below method

[root@localhost bin]# yum whatprovides lsb_release

Last metadata expiration check: 0:05:10 ago on Sat 30 Dec 2023 11:04:11 AM UTC.

redhat-lsb-core-4.1-47.0.1.el8.i686 : LSB Core module support

Repo : ol8_appstream

Matched from:

Filename : /usr/bin/lsb_release

redhat-lsb-core-4.1-47.0.1.el8.x86_64 : LSB Core module support

Repo : ol8_appstream

Matched from:

Filename : /usr/bin/lsb_release

[root@localhost bin]#

Here we see package redhat-lsb-core provides the lsb_release command, so to access lsb_release we need to install the redhat-lsb-core package, let's try to install it

[root@localhost bin]# yum install redhat-lsb-core

Last metadata expiration check: 0:12:20 ago on Sat 30 Dec 2023 11:04:11 AM UTC.

Dependencies resolved.

==============================================================================================================================================================

Package Architecture Version Repository Size

==============================================================================================================================================================

Installing:

redhat-lsb-core x86_64 4.1-47.0.1.el8 ol8_appstream 46 k

Installing dependencies:

m4 x86_64 1.4.18-7.el8 ol8_baseos_latest 222 k

mailx x86_64 12.5-29.el8 ol8_baseos_latest 257 k

ncurses-compat-libs x86_64 6.1-9.20180224.el8 ol8_baseos_latest 328 k

patch x86_64 2.7.6-11.el8 ol8_baseos_latest 139 k

postfix x86_64 2:3.5.8-7.el8 ol8_baseos_latest 1.5 M

redhat-lsb-submod-security x86_64 4.1-47.0.1.el8 ol8_appstream 22 k

spax x86_64 1.5.3-13.el8 ol8_baseos_latest 217 k

Transaction Summary

==============================================================================================================================================================

Install 8 Packages

Total download size: 2.7 M

Installed size: 7.0 M

Is this ok [y/N]: y

Downloading Packages:

(1/8): mailx-12.5-29.el8.x86_64.rpm 980 kB/s | 257 kB 00:00

(2/8): m4-1.4.18-7.el8.x86_64.rpm 820 kB/s | 222 kB 00:00

(3/8): ncurses-compat-libs-6.1-9.20180224.el8.x86_64.rpm 1.1 MB/s | 328 kB 00:00

(4/8): patch-2.7.6-11.el8.x86_64.rpm 1.3 MB/s | 139 kB 00:00

(5/8): spax-1.5.3-13.el8.x86_64.rpm 2.1 MB/s | 217 kB 00:00

(6/8): redhat-lsb-core-4.1-47.0.1.el8.x86_64.rpm 691 kB/s | 46 kB 00:00

(7/8): redhat-lsb-submod-security-4.1-47.0.1.el8.x86_64.rpm 468 kB/s | 22 kB 00:00

(8/8): postfix-3.5.8-7.el8.x86_64.rpm 5.6 MB/s | 1.5 MB 00:00

--------------------------------------------------------------------------------------------------------------------------------------------------------------

Total 4.9 MB/s | 2.7 MB 00:00

Running transaction check

Transaction check succeeded.

Running transaction test

Transaction test succeeded.

Running transaction

Preparing : 1/1

Installing : redhat-lsb-submod-security-4.1-47.0.1.el8.x86_64 1/8

Installing : spax-1.5.3-13.el8.x86_64 2/8

Running scriptlet: spax-1.5.3-13.el8.x86_64 2/8

Running scriptlet: postfix-2:3.5.8-7.el8.x86_64 3/8

Installing : postfix-2:3.5.8-7.el8.x86_64 3/8

Running scriptlet: postfix-2:3.5.8-7.el8.x86_64 3/8

Installing : patch-2.7.6-11.el8.x86_64 4/8

Installing : ncurses-compat-libs-6.1-9.20180224.el8.x86_64 5/8

Installing : mailx-12.5-29.el8.x86_64 6/8

Installing : m4-1.4.18-7.el8.x86_64 7/8

Running scriptlet: m4-1.4.18-7.el8.x86_64 7/8

Installing : redhat-lsb-core-4.1-47.0.1.el8.x86_64 8/8

Running scriptlet: redhat-lsb-core-4.1-47.0.1.el8.x86_64 8/8

Verifying : m4-1.4.18-7.el8.x86_64 1/8

Verifying : mailx-12.5-29.el8.x86_64 2/8

Verifying : ncurses-compat-libs-6.1-9.20180224.el8.x86_64 3/8

Verifying : patch-2.7.6-11.el8.x86_64 4/8

Verifying : postfix-2:3.5.8-7.el8.x86_64 5/8

Verifying : spax-1.5.3-13.el8.x86_64 6/8

Verifying : redhat-lsb-core-4.1-47.0.1.el8.x86_64 7/8

Verifying : redhat-lsb-submod-security-4.1-47.0.1.el8.x86_64 8/8

Installed:

m4-1.4.18-7.el8.x86_64 mailx-12.5-29.el8.x86_64 ncurses-compat-libs-6.1-9.20180224.el8.x86_64 patch-2.7.6-11.el8.x86_64

postfix-2:3.5.8-7.el8.x86_64 redhat-lsb-core-4.1-47.0.1.el8.x86_64 redhat-lsb-submod-security-4.1-47.0.1.el8.x86_64 spax-1.5.3-13.el8.x86_64

Complete!

[root@localhost bin]#

After installation, I was able to access it

[root@localhost bin]# lsb_release

LSB Version: :core-4.1-amd64:core-4.1-noarch

[root@localhost bin]#

To Know details about Linux OS :Oracle, PostgreSQL, MySQL and MongoDB

Atikh Shaikh MongoDB, mysql, oracle, PostgreSQL No comments

In this small article, we are going to see different commands to check the OS version in Linux and other details about the operating system

Here are a few files and commands that can be used

1. Command uname:

Usage uname -a

[oracle@localhost ~]$ uname -a

Linux localhost.localdomain 5.15.0-8.91.4.1.el8uek.x86_64 #2 SMP Tue Mar 7 18:28:34 PST 2023 x86_64 x86_64 x86_64 GNU/Linux

[oracle@localhost ~]$

This command displays the type of os, OS release, OS version version, hardware name, and processor type

2. Command lsb_release:

Usage:lsb_release -a

[root@localhost ~]# lsb_release -a

LSB Version: :core-4.1-amd64:core-4.1-noarch

Distributor ID: OracleServer

Description: Oracle Linux Server release 8.7

Release: 8.7

Codename: n/a

[root@localhost ~]#

This command would display information including the Distributor ID, Description, OS Release, and Codename.

3. File /etc/os-release

Usage: cat /etc/os-release or more /etc/os-release

This file contains almost all the details about the operating system

4. File /etc/issue:

Usage: cat /etc/issue or more /etc/issue

[root@localhost ~]# cat /etc/issue

Kernel \r on an \m

[root@localhost ~]#

This command will give an idea about the kernel details of the operating system

Based on the requirement, you can use a command or file.

MongoDB : How to get config file and log file location

Atikh Shaikh MongoDB No comments

In MongoDB configuration files and log files are important files as far as the daily routine for DBA. We may need to check parameters in the configuration and file and errors in log files. So here we will discuss where and how to check the location of these files

Configuration files (mongod.conf)

The below command will help to list different files and their location, once you run it, the output will look like the below, but make sure you run it through the admin database, you can see highlighted part shows the location and name of the MongoDB configuration file

[Also read - Database and Collections]

db.runCommand({getCmdLineOpts:1})

> use admin

switched to db admin

> db.runCommand({getCmdLineOpts:1});

{

"argv" : [

"C:\\Program Files\\MongoDB\\Server\\5.0\\bin\\mongod.exe",

"--config",

"C:\\Program Files\\MongoDB\\Server\\5.0\\bin\\mongod.cfg",

"--service"

"parsed" : {

"config" : "C:\\Program Files\\MongoDB\\Server\\5.0\\bin\\mongod.cfg",

"net" : {

"bindIp" : "127.0.0.1",

"port" : 27017

"service" : true,

"storage" : {

"dbPath" : "C:\\Program Files\\MongoDB\\Server\\5.0\\data",

"journal" : {

"enabled" : true

}

"systemLog" : {

"destination" : "file",

"logAppend" : true,

"path" : "C:\\Program Files\\MongoDB\\Server\\5.0\\log\\mongod.log"

}

"ok" : 1

}

Log file

In this same command above, you can see the parameter "systemLog" and location is also given there only, marked in red color.

There is one other to check log file location using mongod.conf file, in the configuration file, you can below the parameter

# where to write logging data.

systemLog:

destination: file

logAppend: true

path: C:\Program Files\MongoDB\Server\5.0\log\mongod.log

Transferring file from one server to another server [FTP, SFTP, SCP etc]

Atikh Shaikh MongoDB, mysql, oracle, Oracle 12c, PostgreSQL No comments

There are number of ways to transfer file from one server to another server, below are the few methods to to achieve the same

ftp
sftp
scp
windows software (Filehippo, WinScp , FileZilla etc)

We will discuss these in details

1. FTP transfer

File Transfer Protocols basically is set of rules on computer network to communicate with one another. This FTP tool or utility can be used to transfer files from one server to another server.

Below are the commands to use ftp

$ftp
User :
Password :
ftp> bin -- to transfer in binary format
ftp> cd
ftp> put/get -- put for sending from one server to another and get is vice versa
ftp>bye

2. SFTP transfer

As name suggest SFTP is secure file transfer protocol, it uses full security and authentication functionality of SSH. SFTP is new utility compared to FTP and recommended to use instead of FTP
This utility can be used using below commands
$sftp @
password : ***
sftp>cd
sftp> put/get -- put for sending from one server to another and get is vice versa
sftp> bye

3.SCP

SCP is used for securely copying files from one server system to another server system.
Below is syntax for the same

scp [OPTION] [user@]src_server:] file1 [user@]target_server:]file2
where
[user@]src_server:] file1 -- source file
[user@]target_server:]file2 -- destination file

for example
scp text_file.txt @:/

4. Windows software

There are number of freely available software on internet, choose your favourite one and transfer files using simple GUI
Below are few I came across

FileZilla
Filehippo
WinScp
FireFTP

MongoDB : Capped Collections

Atikh Shaikh MongoDB No comments

There are two types of collections normal collection and capped collection

In comparison to the normal collection, capped collections are created in advance and are fixed in size
Normal collections are created dynamically and automatically grow in size to fit extra data
These capped collections are designed to consume less space and are rotating that means once allocated space is full, it will start writing from older documents again.
Below operations are not allowed on a capped collection

Documents can not be removed
Updates that make documents to grow in size are not allowed

Capped collections can not be sharded

Creating Capped collection

As discussed above, capped collection needs to be created explicitly, we will discuss commands for the same

> db.createCollection("my_cap_col1",

... {"capped" : true, "size":100000});

{ "ok" : 1 }

above command creates capped collection with below details
capped collection name : my_cap_col1
fixed size : 100000 byes

same way capped collection can be created with limit on number of documents
for example

> db.createCollection("my_cap_col2",

... {"capped":true, "size" : 100000, "max" : 100});

{ "ok" : 1 }

> show collections;

my_cap_col1

my_cap_col2

Once capped collections are created, it can not be modified, it must be dropped and recreated with desired parameters

Converting normal collection to capped collection

> db.runCommand({"convertToCapped": "techno_col",size:10000});

{ "ok" : 1 }

There is no way to convert capped collection to normal collection

mongodb-technodba-capped-collection, normal to capped collection, capped to normal collection

Creating User Account in MongoDB

Atikh Shaikh MongoDB No comments

For any database whether it is RDBMS or NoSQL, the user account is a very important aspect and is a must to connect to a database
There are different types of users depending on usage like, admin user account, read-only account, read write only.
Users can be created or added to the database using db.createUser() method available with MongoDB
The db.createUser() method accepts a document object that enables you to specify the username, roles and password for user to be created

Definition of db.createUser() method
db.createUser(user, writeConcern)

Field	Type	Description
User	Document	The document with authentication and access information about user
writeConcern	Document	Optional, the level of writeConcern for creation operation

The user document has the following fields

Field	Type	Description
user	String	The name of the new user
pwd	String	The user password
customData	Document	Optional, any information about user
roles	Array	This defines roles, The roles granted to a user can be an empty array[] to create a user without any roles
AuthenticationRestrictions	Array	Optional, the authentication restrictions the server enforces on the user. Specifies a list of IP addresses and CIDR ranges from which user will be able to connect
Mechanisms	Array	Optional, specify the specific SCRAM mechanism for creating SCRAM user creation
passwordDigester	string	Optional, Indicates whether the server or the client digest the password

Roles
In the role field, you can specify the build-in roles and user-defined roles. You can specify directly role name or in the form of a document as well
i.e.

"readWrite" or {role : "" : db ""}

External Credentials
Users created on $external database should have credentials stored externally to MongoDB
Local database
user can not be created on local database
Examples
Create account with roles assigned

> db.createUser({ user : "tech_owner",

... pwd : "techo!23",

... customData : {user : "blogUser"},

... roles :[{role: "clusterAdmin",

... db : "admin" },

... "readWrite"]}

... );

Successfully added user: {

"user" : "tech_owner",

"customData" : {

"user" : "blogUser"

"roles" : [

{

"role" : "clusterAdmin",

"db" : "admin"

"readWrite"

]

}

Create an account with roles

> db.createUser({ user : "tech_user",

... pwd : "techo!23",

... roles :["readWrite", "dbAdmin"]}

... );

Successfully added user: { "user" : "tech_user", "roles" : [ "readWrite", "dbAdmin" ] }

Create user without any roles

> db.createUser({ user : "tech_wo_roles",

... pwd : "techo!23",

... roles :[]

... }

... );

Successfully added user: { "user" : "tech_wo_roles", "roles" : [ ] }

Listing users created

> db.getUsers();

[

{

"_id" : "techno_db.tech_owner",

"user" : "tech_owner",

"db" : "techno_db",

"customData" : {

"user" : "blogUser"

"roles" : [

{

"role" : "clusterAdmin",

"db" : "admin"

{

"role" : "readWrite",

"db" : "techno_db"

}

"mechanisms" : [

"SCRAM-SHA-1"

]

{

"_id" : "techno_db.tech_user",

"user" : "tech_user",

"db" : "techno_db",

"roles" : [

{

"role" : "readWrite",

"db" : "techno_db"

{

"role" : "dbAdmin",

"db" : "techno_db"

}

"mechanisms" : [

"SCRAM-SHA-1"

]

{

"_id" : "techno_db.tech_wo_roles",

"user" : "tech_wo_roles",

"db" : "techno_db",

"roles" : [ ],

"mechanisms" : [

"SCRAM-SHA-1"

]

}

]

Removing/Dropping User in MongoDB
First list the users using db.getUsers() method and decide which one to drop
then use db.dropUser() method to drop user, this dropUser() method takes username as argument
We will drop tech_wo_roles user

> db.dropUser("tech_wo_roles");

true

If you want to drop all the users if you can user db.dropAllUsers() method.

More will come on MongoDB. follow this space for more and explore more.

lsb_release: command not found... : Linux/ Database Admin

To Know details about Linux OS :Oracle, PostgreSQL, MySQL and MongoDB

MongoDB : How to get config file and log file location

Transferring file from one server to another server [FTP, SFTP, SCP etc]

1. FTP transfer

2. SFTP transfer

3.SCP

4. Windows software

MongoDB : Capped Collections

Creating User Account in MongoDB

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