Hi sir... I'm following your channel and I watched your updated linux videos that's helpful to everyone sir. Could you please explain briefly on load average and time interval. if server get load average is full how we will know and how to troubleshoot on it sir.
Load Average and Time Interval Load Average: Load average is a metric that indicates the average number of processes that are either running or waiting for CPU time over a specific period. It's typically represented as three numbers, showing the average over the last 1, 5, and 15 minutes (e.g., 2.35, 1.75, 1.55). Time Interval: The three values correspond to: 1-minute load average: Reflects the recent load on the system. 5-minute load average: Smooths out short-term spikes. 15-minute load average: Indicates longer-term trends. Monitoring Load Average How to Check Load Average: Use the top or uptime command to view the load average: top # or uptime The output will show the three load average values. Understanding Full Load: A "full" load average is subjective and depends on the number of CPU cores. Generally: If the load average is equal to the number of CPU cores, the CPU is fully utilized. For example, a load average of 4.00 on a 4-core system indicates full CPU utilization. Troubleshooting High Load Average Steps to Troubleshoot: Identify Resource-Consuming Processes: Use top or htop to see which processes are using the most CPU. Look for processes with high CPU usage or running state (R). Check CPU Usage: Run vmstat to get an overview of system performance. Look at the CPU columns, particularly the us, sy, and id values (user, system, and idle times). Examine Disk I/O: High load can also be caused by disk I/O issues. Use iostat or iotop to check disk I/O activity and identify any bottlenecks. Review Memory Usage: Check if the system is swapping memory, which can increase load. Use free -m or vmstat to see memory and swap usage. Analyze System Logs: Look at /var/log/syslog or /var/log/messages for any unusual entries or errors. Logs can provide hints on what might be causing the high load. Network Activity: If the server is handling many network connections, it can increase the load. Use tools like netstat or ss to monitor network connections. Example Commands: top htop vmstat 1 5 iostat -xz 1 5 iotop free -m cat /var/log/syslog netstat -tulnp ss -s Action Steps: Terminate or Restart: If a specific process is causing the load, consider terminating or restarting it. Optimize Code: For applications causing high load, review and optimize the code. Upgrade Resources: If the load is consistently high, you may need more CPU or memory resources. Load Balancing: Distribute the load across multiple servers if possible. By monitoring the load average and taking appropriate actions, you can maintain optimal server performance and minimize downtime.
1. If you are looking for a user-friendly experience with a large community and extensive online resources, Ubuntu might be the better choice. 2. If you aim to work in an enterprise environment and want to pursue certifications that are highly regarded in the industry, Red Hat (or CentOS) could be more beneficial.
File System Capacity Management: 1.Monitor Disk Usage: Use df to check disk space usage for all mounted filesystems df -h 2. Identify Large Files and Directories: du -h --max-depth=1 / 3. Automate Monitoring: Set up automated monitoring tools like cron jobs combined with df and du to regularly check disk usage and send alerts if usage exceeds certain thresholds. 0 0 * * * /usr/bin/df -h > /var/log/disk_usage.log 4. Clear Unnecessary Files: Regularly clean up unnecessary files, such as temporary files, old logs, and cache files. Automate this process with scripts: find /tmp -type f -atime +10 -delete find /var/log -name "*.log" -type f -mtime +30 -delete 5.Extend File System: If a filesystem is running out of space, you may need to extend it. Example for LVM (Logical Volume Manager) lvextend -L +10G /dev/vg_name/lv_name resize2fs /dev/vg_name/lv_name File System Integrity Checking: 1. Use fsck (File System Check): fsck is a tool to check and repair file system inconsistencies. Run fsck on an unmounted filesystem or in single-user mode: fsck /dev/sdXn Replace /dev/sdXn with the appropriate device identifier. 2. Schedule Regular Checks: Automate periodic checks using systemd timers or cron jobs. Example cron job to check /dev/sda1 weekly 0 2 * * 0 /sbin/fsck /dev/sda1 3. Monitor File System Health: Use tools like smartctl for monitoring the health of storage devices smartctl -a /dev/sda 4.Enable Journaling (for Ext3/Ext4): Journaling helps maintain file system integrity by keeping track of changes not yet committed to the file system. Ensure journaling is enabled on ext3/ext4 filesystems. 5.Use Filesystem-Specific Tools: Different filesystems have specific tools for checking and maintaining integrity, such as xfs_repair for XFS filesystems: xfs_repair /dev/sdXn
I M linux system admin having 4 years of experience + aws solution associate 1year experience so how much CTC should I demand as per IT market and which path best for me for get best salary package as per my current position please guide me..
Hello sir, one query When we do scp between two servers, why it shows more data size on destination server than source server..any specific reason? Thanks
When transferring files using SCP (Secure Copy Protocol) between two servers, it’s not uncommon to notice that the size of the data on the destination server appears larger than the size on the source server. Here are some specific reasons why this might happen: 1. File System Differences: Different file systems handle file storage in various ways. For example, a file system might use larger block sizes, leading to more disk space being used on the destination server compared to the source server. 2. File Compression: If the files on the source server are compressed (e.g., using a filesystem that supports compression), the actual size on disk could be smaller than the uncompressed size. When copied, the destination server might not have compression enabled, leading to larger file sizes. 3. Sparse Files: Sparse files contain empty blocks that are not physically written to the disk. Some file systems or tools may not handle sparse files efficiently, causing the actual stored data to increase when copied to a new location. 4. Metadata Overhead: Different file systems and storage solutions have varying amounts of metadata overhead. The destination server might be using a file system that stores more metadata for each file, increasing the overall disk usage. 5. Transfer Protocol Overhead: In some rare cases, the way SCP handles the data transfer might introduce slight differences in file sizes due to protocol overhead. However, this is usually minimal. 6. Disk Allocation Differences: Some file systems allocate disk space in chunks or clusters, and the size of these chunks can vary. If the destination server uses a larger allocation unit size, the files could occupy more space. 7. Backup and Restore Operations: If additional files such as backup logs or temporary files are generated during the SCP process, these might contribute to the increased size on the destination server. 8. Storage Quotas and Reporting Differences: The method by which disk usage is reported can vary between systems. One system might include additional overhead in its reported file sizes that another does not
Red Hat Certified System Administrator (RHCSA) and Red Hat Certified Engineer (RHCE) 1.RHCSA: This certifies your skills in handling Red Hat Enterprise Linux systems, including basic administration, installation, and troubleshooting. 2.RHCE: This is an advanced certification focusing on more complex tasks, such as configuring static routes, packet filtering, and setting up various network services. If you're aiming for a career in enterprise environments, consider the Red Hat certifications (RHCSA and RHCE), as Red Hat Enterprise Linux is widely used in corporate settings.
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Great session🙌
maximum point cover about Linux & very useful in day to day operation
Keep watching
Before unmounting the file system, we have to take back up of the file system
After 6 year of experience the interviewer are not asking that types of questions, that type of questions are ask for1 years or fresher.
Can you post such interview questions you’re asking for.?
Great session wonderful work by the mock interviewer calm and good 👍
Glad you enjoyed it
Appreciate your work Sir
Thanks and welcome
Hi sir... I'm following your channel and I watched your updated linux videos that's helpful to everyone sir.
Could you please explain briefly on load average and time interval. if server get load average is full how we will know and how to troubleshoot on it sir.
Load Average and Time Interval
Load Average:
Load average is a metric that indicates the average number of processes that are either running or waiting for CPU time over a specific period.
It's typically represented as three numbers, showing the average over the last 1, 5, and 15 minutes (e.g., 2.35, 1.75, 1.55).
Time Interval:
The three values correspond to:
1-minute load average: Reflects the recent load on the system.
5-minute load average: Smooths out short-term spikes.
15-minute load average: Indicates longer-term trends.
Monitoring Load Average
How to Check Load Average:
Use the top or uptime command to view the load average:
top
# or
uptime
The output will show the three load average values.
Understanding Full Load:
A "full" load average is subjective and depends on the number of CPU cores. Generally:
If the load average is equal to the number of CPU cores, the CPU is fully utilized.
For example, a load average of 4.00 on a 4-core system indicates full CPU utilization.
Troubleshooting High Load Average
Steps to Troubleshoot:
Identify Resource-Consuming Processes:
Use top or htop to see which processes are using the most CPU.
Look for processes with high CPU usage or running state (R).
Check CPU Usage:
Run vmstat to get an overview of system performance.
Look at the CPU columns, particularly the us, sy, and id values (user, system, and idle times).
Examine Disk I/O:
High load can also be caused by disk I/O issues.
Use iostat or iotop to check disk I/O activity and identify any bottlenecks.
Review Memory Usage:
Check if the system is swapping memory, which can increase load.
Use free -m or vmstat to see memory and swap usage.
Analyze System Logs:
Look at /var/log/syslog or /var/log/messages for any unusual entries or errors.
Logs can provide hints on what might be causing the high load.
Network Activity:
If the server is handling many network connections, it can increase the load.
Use tools like netstat or ss to monitor network connections.
Example Commands:
top
htop
vmstat 1 5
iostat -xz 1 5
iotop
free -m
cat /var/log/syslog
netstat -tulnp
ss -s
Action Steps:
Terminate or Restart: If a specific process is causing the load, consider terminating or restarting it.
Optimize Code: For applications causing high load, review and optimize the code.
Upgrade Resources: If the load is consistently high, you may need more CPU or memory resources.
Load Balancing: Distribute the load across multiple servers if possible.
By monitoring the load average and taking appropriate actions, you can maintain optimal server performance and minimize downtime.
@@EngrAbhishekRoshan thanks for providing information sir🙏
Which is better to learn for begginers redhat or ubuntu for 2 years experience
1. If you are looking for a user-friendly experience with a large community and extensive online resources, Ubuntu might be the better choice.
2. If you aim to work in an enterprise environment and want to pursue certifications that are highly regarded in the industry, Red Hat (or CentOS) could be more beneficial.
@@EngrAbhishekRoshan Thank you for your reply
Hello sir, please explain how to
Perform the file system capacity management and integrity checking
File System Capacity Management:
1.Monitor Disk Usage:
Use df to check disk space usage for all mounted filesystems
df -h
2. Identify Large Files and Directories:
du -h --max-depth=1 /
3. Automate Monitoring:
Set up automated monitoring tools like cron jobs combined with df and du to regularly check disk usage and send alerts if usage exceeds certain thresholds.
0 0 * * * /usr/bin/df -h > /var/log/disk_usage.log
4. Clear Unnecessary Files:
Regularly clean up unnecessary files, such as temporary files, old logs, and cache files.
Automate this process with scripts:
find /tmp -type f -atime +10 -delete
find /var/log -name "*.log" -type f -mtime +30 -delete
5.Extend File System:
If a filesystem is running out of space, you may need to extend it.
Example for LVM (Logical Volume Manager)
lvextend -L +10G /dev/vg_name/lv_name
resize2fs /dev/vg_name/lv_name
File System Integrity Checking:
1. Use fsck (File System Check):
fsck is a tool to check and repair file system inconsistencies.
Run fsck on an unmounted filesystem or in single-user mode:
fsck /dev/sdXn
Replace /dev/sdXn with the appropriate device identifier.
2. Schedule Regular Checks:
Automate periodic checks using systemd timers or cron jobs.
Example cron job to check /dev/sda1 weekly
0 2 * * 0 /sbin/fsck /dev/sda1
3. Monitor File System Health:
Use tools like smartctl for monitoring the health of storage devices
smartctl -a /dev/sda
4.Enable Journaling (for Ext3/Ext4):
Journaling helps maintain file system integrity by keeping track of changes not yet committed to the file system.
Ensure journaling is enabled on ext3/ext4 filesystems.
5.Use Filesystem-Specific Tools:
Different filesystems have specific tools for checking and maintaining integrity, such as xfs_repair for XFS filesystems:
xfs_repair /dev/sdXn
Thankyou sir
I M linux system admin having 4 years of experience + aws solution associate 1year experience so how much CTC should I demand as per IT market and which path best for me for get best salary package as per my current position please guide me..
Are you currently working as Linux administrator?
Hello sir, one query
When we do scp between two servers, why it shows more data size on destination server than source server..any specific reason? Thanks
When transferring files using SCP (Secure Copy Protocol) between two servers, it’s not uncommon to notice that the size of the data on the destination server appears larger than the size on the source server. Here are some specific reasons why this might happen:
1. File System Differences: Different file systems handle file storage in various ways. For example, a file system might use larger block sizes, leading to more disk space being used on the destination server compared to the source server.
2. File Compression: If the files on the source server are compressed (e.g., using a filesystem that supports compression), the actual size on disk could be smaller than the uncompressed size. When copied, the destination server might not have compression enabled, leading to larger file sizes.
3. Sparse Files: Sparse files contain empty blocks that are not physically written to the disk. Some file systems or tools may not handle sparse files efficiently, causing the actual stored data to increase when copied to a new location.
4. Metadata Overhead: Different file systems and storage solutions have varying amounts of metadata overhead. The destination server might be using a file system that stores more metadata for each file, increasing the overall disk usage.
5. Transfer Protocol Overhead: In some rare cases, the way SCP handles the data transfer might introduce slight differences in file sizes due to protocol overhead. However, this is usually minimal.
6. Disk Allocation Differences: Some file systems allocate disk space in chunks or clusters, and the size of these chunks can vary. If the destination server uses a larger allocation unit size, the files could occupy more space.
7. Backup and Restore Operations: If additional files such as backup logs or temporary files are generated during the SCP process, these might contribute to the increased size on the destination server.
8. Storage Quotas and Reporting Differences: The method by which disk usage is reported can vary between systems. One system might include additional overhead in its reported file sizes that another does not
Thank you sir for your quick response 🙏..your responses help us to learn more.
which linux certification do you recommend for beginner that could help in getting a job?
Red Hat Certified System Administrator (RHCSA) and Red Hat Certified Engineer (RHCE)
1.RHCSA: This certifies your skills in handling Red Hat Enterprise Linux systems, including basic administration, installation, and troubleshooting.
2.RHCE: This is an advanced certification focusing on more complex tasks, such as configuring static routes, packet filtering, and setting up various network services.
If you're aiming for a career in enterprise environments, consider the Red Hat certifications (RHCSA and RHCE), as Red Hat Enterprise Linux is widely used in corporate settings.
@@EngrAbhishekRoshan thnak you
Sir, what is cost for mock interview
Here's the link to connect with me and to get the complete insight for Interview Preparation, Career Guidance, Mock Interview and Resume Preparation.
th-cam.com/channels/n2ZGN0TEGhgoDDiT8S3m4w.htmljoin