DEV Community: shun

Configuring vm.max_map_count for Elasticsearch in Docker using WSL

shun — Sat, 12 Aug 2023 11:05:28 +0000

Configuring vm.max_map_count for Elasticsearch in Docker using WSL

When running Elasticsearch on Docker, you might encounter an error message like the following if the default value of vm.max_map_count is too low:

max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]

To resolve this error, you need to use Windows Subsystem for Linux (WSL) to properly configure the value of vm.max_map_count.

Accessing Docker Desktop's WSL Environment
Open a command prompt and access the WSL environment of Docker Desktop using the following command:

PS C:\work\project\logstash> wsl -d docker-desktop

Modifying System Settings
Once inside the WSL environment, use the following command to change the value of vm.max_map_count:

DESKTOP-XXXXXXX:/path/to/directory# sysctl -w vm.max_map_count=262144

Exiting the WSL Environment
Exit the WSL environment using the following command:

DESKTOP-XXXXXXX:/path/to/directory# exit

Following these steps should resolve the Elasticsearch error related to vm.max_map_count, allowing Elasticsearch to run smoothly.

Elasticsearch, Logstash, and Kibana Compatibility Matrix

shun — Sat, 12 Aug 2023 10:42:07 +0000

Compatibility Matrix for Elasticsearch, Logstash, and Kibana

Detailed compatibility information for Elasticsearch, Logstash, and Kibana can be found on Elastic's official support matrix page. The following matrix summarizes the compatibility of major versions, focusing on 7.x and 8.x.

Compatibility Table

Product	Version	Compatible with Elasticsearch	Compatible with Logstash	Compatible with Kibana
Elasticsearch	7.x	-	7.x	7.x
Logstash	7.x	7.x	-	-
Kibana	7.x	7.x	-	-
Elasticsearch	8.x	-	8.x	8.x
Logstash	8.x	8.x	-	-
Kibana	8.x	8.x	-	-

Please note that this table provides a general overview of compatibility, and specifics about sub-versions and certain features/settings can be found in the official documentation.

More Information

For detailed information about compatibility and compatibility with other versions/products, please refer to Elastic's official support matrix page.

We hope this compatibility matrix assists you in making informed decisions about choosing appropriate versions and managing your systems. If you have further questions or require more detailed information, please consult the official support matrix page or let us know.

Standard Linux Commands and Their Outputs

shun — Sat, 12 Aug 2023 08:12:23 +0000

File Operations

ls: List directory contents

  $ ls
  file1.txt  file2.txt  dir1/

pwd: Print working directory

  $ pwd
  /home/user

Text Operations

cat: Display file content

  $ cat file1.txt
  This is the content of file1.

head: Display the beginning of a file

  $ head file1.txt
  First line of the file.

tail: Display the end of a file

  $ tail file1.txt
  Last line of the file.

System Information

uname -a: Display system information

  $ uname -a
  Linux hostname 5.4.0-42-generic #46-Ubuntu SMP Fri Jul 10 00:24:02 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

free: Display memory usage

  $ free -h
            total        used        free      shared  buff/cache   available
  Mem:      7.7Gi       1.2Gi       5.8Gi       123Mi       717Mi       6.2Gi
  Swap:     2.0Gi          0B       2.0Gi

Networking

ping: Test network connection

  $ ping -c 4 google.com
  PING google.com (172.217.22.14) 56(84) bytes of data.
  64 bytes from fra15s11-in-f14.1e100.net (172.217.22.14): icmp_seq=1 ttl=53 time=29.3 ms
  ...

Miscellaneous

echo: Display a line of text
bash $ echo "Hello, World!" Hello, World!
history: Display command history
bash $ history 1 ls 2 cd .. 3 pwd ...

File and Directory Operations in Linux Commands

shun — Sat, 12 Aug 2023 08:12:21 +0000

Creating and Removing

touch: Create an empty file.

  $ touch newfile.txt

mkdir: Create a new directory.

  $ mkdir new_directory

rm: Remove files.
- -r (or --recursive): Remove directories and their contents.
- -f: Force removal without confirmation.
```
$ rm file_to_remove.txt
$ rm -rf directory_to_remove/
```
rmdir: Remove an empty directory.

  $ rmdir empty_directory

Copying, Moving, and Renaming

cp: Copy files or directories.
- -r: Recursively copy directories.
- -i: Prompt before overwriting files.
```
$ cp source.txt destination.txt
$ cp -ri source_directory/ destination_directory/
```
mv: Move or rename files or directories.
- -i: Prompt before overwriting files.
```
$ mv -i oldname.txt newname.txt
```

Listing and Navigating

ls: List directory contents.
- -l: Display in long format.
- -a: Show hidden files.
- -h: Display sizes in human-readable format.
```
$ ls -lah
```
pwd: Print the current working directory.

  $ pwd

cd: Change the current directory.

  $ cd /path/to/directory/

File Content Viewing

cat: Display the entire content of a file.

  $ cat file.txt
  This is the content of file.txt.

less: View file content with pagination. No direct output, but provides an interactive view.

  $ less file.txt

head: Display the beginning of a file.

  $ head file.txt
  First line of the file.

tail: Display the end of a file.

-f: Follow the content of a file in real-time.

$ tail -f /var/log/syslog
Aug 11 12:34:56 hostname program[1234]: Log message here.

File and Directory Information

stat: Display detailed information about a file or directory.

  $ stat file.txt
  File: file.txt
  Size: 1234       Blocks: 8          IO Block: 4096   regular file
  Device: 801h/2049d      Inode: 123456      Links: 1
  Access: (0644/-rw-r--r--)  Uid: ( 1000/    user)   Gid: ( 1000/    user)

file: Determine the type of a file.

  $ file image.jpg
  image.jpg: JPEG image data, JFIF standard 1.01

Searching for Files

find: Search for files in a directory hierarchy.

  $ find /path/to/search/ -name "pattern*"
  /path/to/search/pattern1.txt
  /path/to/search/subdir/pattern2.txt

Text Processing in Linux

shun — Sat, 12 Aug 2023 08:12:20 +0000

Searching within Text

grep: Search for a pattern within files.
- -i: Ignore case.
- -r or -R: Recursively search in directories.
- -v: Invert the search (return lines that don't match).
```
$ grep "search_term" file.txt
This line contains the search_term.
```

```bash
$ grep -i "Search_Term" file.txt
This line contains the search_term.
```

Filtering and Transforming Text

awk: A versatile programming language for working on files.

  $ echo -e "a 1\nb 2\nc 3" | awk '{print $2}'
  1
  2
  3

sed: Stream editor for filtering and transforming text.

  $ echo "Hello World" | sed 's/World/Universe/'
  Hello Universe

Sorting and Counting

sort: Sort lines in text files.
- -r: Reverse the result of comparisons (descending).
- -n: Compare according to string numerical value.
```
$ echo -e "banana\napple\ncherry" | sort
apple
banana
cherry
```
uniq: Report or omit repeated lines.
- -c: Prefix lines by the number of occurrences.
```
$ echo -e "a\na\nb\nb\nb\nc" | uniq -c
  2 a
  3 b
  1 c
```

wc: Count words, lines, and characters in files.
- -l: Count lines.
- -w: Count words.
- -c: Count bytes.

  ```bash
  $ echo "Hello World" | wc -w
  2
  ```

Text Display

cat: Concatenate and display the content of files.

  $ cat file.txt
  This is the content of file.txt.

tac: Display files in reverse.

  $ echo -e "line1\nline2\nline3" | tac
  line3
  line2
  line1

nl: Number lines of files.

  $ echo -e "line1\nline2\nline3" | nl
  1  line1
  2  line2
  3  line3

head: Display the beginning of a file.
- -n: Specify the number of lines to show.
```
  $ echo -e "line1\nline2\nline3" | head -n 2
  line1
  line2
```
tail: Display the end of a file.
- -n: Specify the number of lines to show.
- -f: Follow the content of a file in real-time.
```
  $ echo -e "line1\nline2\nline3" | tail -n 2
  line2
  line3
```

Permissions and Ownership in Linux

shun — Sat, 12 Aug 2023 08:12:19 +0000

In Linux, files and directories have three types of permissions (read, write, execute) for three types of users (owner, group, others).
r (read): Allows reading the file's contents.
w (write): Permits modifying the file's contents.
x (execute): Enables executing the file as a program.

Changing File Permissions with chmod

You can use the chmod command to modify access permissions for files and directories.

Symbolic Mode:

  $ chmod u+x file.txt  # Add execute permission to the owner
  $ chmod g-w file.txt  # Remove write permission from the group
  $ chmod o=r file.txt  # Set read-only permission for others

Octal Mode:

  $ chmod 755 file.txt  # rwxr-xr-x: Owner has all permissions, group has read and execute, others have read and execute

Changing File Owner and Group with chown

The chown command lets you change the owner and group of files and directories.

$ chown newowner file.txt          # Change the file's owner
$ chown newowner:newgroup file.txt # Change both the owner and group of the file

Changing Group Ownership with chgrp

Using the chgrp command, you can change the group ownership of files and directories.

$ chgrp newgroup file.txt

Viewing File Permissions with ls -l

The ls -l command displays file and directory access permissions, owner, and group.

$ ls -l
-rwxr-xr-x 1 owner group 1234 Jan 1 12:00 file.txt

Understanding and managing permissions and ownership is crucial for maintaining security and proper access control in a Linux system.

System Operations in Linux

shun — Sat, 12 Aug 2023 08:12:18 +0000

Performing system operations is a crucial part of managing a Linux system. Here are some essential commands for handling

System Operations in Linux

`ps`: Display currently active processes

Basic usage:

  $ ps

Show all processes for all users:

  $ ps aux

`top`: Real-time Process Monitoring

Basic usage:

  $ top

Some key commands while top is running:
- q: Quit top
- u: Show processes for a specific user
- k: Kill a specific process

`kill`: Terminate Processes

Basic usage (using process ID):

  $ kill [process_id]

Send a specific signal to a process (e.g., sending the SIGKILL signal):

  $ kill -[signal] [process_id]

For example, to send the SIGKILL signal:

```bash
$ kill -9 [process_id]
```

`shutdown`: Shutdown or restart the system

Shutdown immediately:

  $ shutdown -h now

Reboot immediately:

  $ shutdown -r now

Shutdown with a message:

  $ shutdown -h +10 "System will shutdown in 10 minutes"

This will shut down the system in 10 minutes and broadcast the provided message to all logged-in users.

Understanding these system operation commands is essential for effectively managing and maintaining a Linux system.

Windows Command Prompt vs Linux Commands

shun — Sat, 12 Aug 2023 08:12:16 +0000

File and Directory Operations

Windows Command	Description	Linux Command
dir	List directory contents	ls
cd	Change directory	cd
mkdir	Create a new directory	mkdir
rmdir	Remove a directory	rmdir or rm -r
copy	Copy files	cp
move	Move or rename files	mv
del	Delete a file	rm
type	Display contents of a file	cat

Text Processing

Windows Command	Description	Linux Command
find	Search in a file	grep
sort	Sort input	sort
more	Display output one screen	more or less

System Operations

Windows Command	Description	Linux Command
tasklist	List running processes	ps
taskkill	Kill a process	kill
shutdown	Shutdown or restart system	shutdown

Networking

Windows Command	Description	Linux Command
ipconfig	Display IP configuration	ifconfig or ip a
ping	Send ICMP echo request	ping
netstat	Network statistics	netstat

Disk Operations

Windows Command	Description	Linux Command
chkdsk	Check disk for errors	fsck
diskpart	Disk partitioning	fdisk or parted
format	Format a disk	mkfs

Standard Windows Commands and Their Outputs

shun — Sat, 12 Aug 2023 08:12:15 +0000

File Operations

dir: List directory contents

  C:\> dir
  2023-08-11  10:00 AM    <DIR>          dir1
  2023-08-11  09:58 AM                20 file1.txt
  2023-08-11  09:59 AM                30 file2.txt

cd: Print working directory

  C:\> cd
  C:\Users\user

Text Operations

type: Display file content

  C:\> type file1.txt
  This is the content of file1.

more: Display the beginning of a file (Windows doesn't have an exact equivalent to head, but more can be used to view the contents)

  C:\> more file1.txt
  First line of the file.

more: Display the end of a file (Again, Windows doesn't have an exact tail equivalent, but you can scroll through with more)

  C:\> more file1.txt
  Last line of the file.

System Information

systeminfo: Display system information (This provides a lot of information, more than uname -a in Linux)

  C:\> systeminfo

wmic OS get FreePhysicalMemory,TotalVisibleMemorySize /Value: Display memory usage (This is a bit more complex in Windows compared to Linux's free)

  C:\> wmic OS get FreePhysicalMemory,TotalVisibleMemorySize /Value

Networking

ping: Test network connection

  C:\> ping google.com

Miscellaneous

echo: Display a line of text

  C:\> echo Hello, World!
  Hello, World!

doskey /history: Display command history (This might not capture all history like Linux's history command, but it's the closest built-in command)

  C:\> doskey /history

File and Directory Operations in Windows Commands

shun — Sat, 12 Aug 2023 08:12:15 +0000

Creating and Removing

echo.: Create an empty file.

  C:\> echo. > newfile.txt

mkdir: Create a new directory.

  C:\> mkdir new_directory

del: Remove files.

  C:\> del file_to_remove.txt

rmdir: Remove a directory (either empty or with contents).

  C:\> rmdir /s /q directory_to_remove

Copying, Moving, and Renaming

copy: Copy files.

  C:\> copy source.txt destination.txt

xcopy: Copy directories.

  C:\> xcopy /s /i source_directory destination_directory

move: Move or rename files or directories.

  C:\> move oldname.txt newname.txt

Listing and Navigating

dir: List directory contents.

  C:\> dir

cd: Display or change the current directory.

  C:\> cd \path\to\directory

File Content Viewing

type: Display the entire content of a file.

  C:\> type file.txt

more: View file content with pagination.

  C:\> more file.txt
  (Note: Windows doesn't have direct equivalents to `head` and `tail` commands in its basic command prompt.)

File and Directory Information

dir: Display detailed information about a file or directory.

  C:\> dir file.txt
  (Note: Windows doesn't have a direct equivalent to the `file` command in its basic command prompt.)

Searching for Files

dir: Search for files in a directory.

  C:\> dir /s /b \path\to\search\*pattern*.txt

Text Processing in Windows

shun — Sat, 12 Aug 2023 08:12:13 +0000

Searching within Text

findstr: Search for strings in files.
- /I: Ignore case.
- /S: Searches for matching files in the current directory and all subdirectories.
- /V: Print only lines that do not contain a match.
```
C:\> findstr "search_term" file.txt
This line contains the search_term.
```

```bash
C:\> findstr /I "Search_Term" file.txt
This line contains the search_term.
```

Filtering and Transforming Text

There's no direct equivalent to awk in Windows, but you can use PowerShell or other scripting languages for similar tasks.
powershell -Command "(Get-Content file.txt) -replace 'World', 'Universe'": Use PowerShell to replace text.

  C:\> echo Hello World | powershell -Command "$input -replace 'World', 'Universe'"
  Hello Universe

Sorting and Counting

sort: Sort input.

  C:\> echo banana & echo apple & echo cherry | sort
  apple
  banana
  cherry

There's no direct uniq equivalent in Windows, but you can use PowerShell for similar tasks.
find /c /v "": Count lines in a file.

  C:\> echo Hello World | find /c /v ""
  1

Text Display

type: Display the content of files.

  C:\> type file.txt
  This is the content of file.txt.

There's no direct tac equivalent in Windows, but you can use PowerShell for similar tasks.
more +n: Display content starting from the nth line. (Similar to tail)

  C:\> echo line1 & echo line2 & echo line3 | more +1
  line2
  line3

System Operations in Windows

shun — Sat, 12 Aug 2023 08:12:11 +0000

Performing system operations is a crucial part of managing a Windows system. Here are some essential commands for handling system operations.

`tasklist`: Display currently active processes

Basic usage:

  C:\> tasklist

`taskmgr`: Real-time Process Monitoring

Basic usage:

  C:\> taskmgr

This will open the Task Manager GUI where you can monitor and manage processes.

`taskkill`: Terminate Processes

Basic usage (using process ID):

  C:\> taskkill /PID [process_id]

Terminate a process by its name:

  C:\> taskkill /IM [process_name]

For example, to kill a process named "notepad.exe":

```bash
C:\> taskkill /IM notepad.exe
```

`shutdown`: Shutdown or restart the system

Shutdown immediately:

  C:\> shutdown /s /t 0

Reboot immediately:

  C:\> shutdown /r /t 0

Shutdown with a message:

  C:\> shutdown /s /t 600 /c "System will shutdown in 10 minutes"

This will shut down the system in 10 minutes and display the provided message.

Understanding these system operation commands is essential for effectively managing and maintaining a Windows system.

DEV Community: shun

Configuring vm.max_map_count for Elasticsearch in Docker using WSL

Configuring vm.max_map_count for Elasticsearch in Docker using WSL

Elasticsearch, Logstash, and Kibana Compatibility Matrix

Compatibility Matrix for Elasticsearch, Logstash, and Kibana

Compatibility Table

More Information

Standard Linux Commands and Their Outputs

File Operations

Text Operations

System Information

Networking

Miscellaneous

File and Directory Operations in Linux Commands

Creating and Removing

Copying, Moving, and Renaming

Listing and Navigating

File Content Viewing

File and Directory Information

Searching for Files

Text Processing in Linux

Searching within Text

Filtering and Transforming Text

Sorting and Counting

Text Display

Permissions and Ownership in Linux

Changing File Permissions with chmod

Changing File Owner and Group with chown

Changing Group Ownership with chgrp

Viewing File Permissions with ls -l

System Operations in Linux

System Operations in Linux

ps: Display currently active processes

top: Real-time Process Monitoring

kill: Terminate Processes

shutdown: Shutdown or restart the system

Windows Command Prompt vs Linux Commands

File and Directory Operations

Text Processing

System Operations

Networking

Disk Operations

Standard Windows Commands and Their Outputs

File Operations

Text Operations

System Information

Networking

Miscellaneous

File and Directory Operations in Windows Commands

Creating and Removing

Copying, Moving, and Renaming

Listing and Navigating

File Content Viewing

File and Directory Information

Searching for Files

Text Processing in Windows

Searching within Text

Filtering and Transforming Text

Sorting and Counting

Text Display

System Operations in Windows

tasklist: Display currently active processes

taskmgr: Real-time Process Monitoring

taskkill: Terminate Processes

shutdown: Shutdown or restart the system

`ps`: Display currently active processes

`top`: Real-time Process Monitoring

`kill`: Terminate Processes

`shutdown`: Shutdown or restart the system

`tasklist`: Display currently active processes

`taskmgr`: Real-time Process Monitoring

`taskkill`: Terminate Processes

`shutdown`: Shutdown or restart the system