RAID: You must know about RAIDs if you are in hosting industry. As client or as an server admin. As a client, we must have idea about various types of RAIDs with their functionality and advantages-disadvantages then n then only we can choose best server hardware for us. Sysadmin must know the RAID administration part, to provide best quality support to premium clients.
RAID types: Basically, there are 2 types of RAIDs available.
1. Hardware Raid : Its managed by hardware RAID controller.
Eg. 3ware/Sas/Megasas/Adaptec etc.
2. Software Raid : Its managed by/throgh OS.
Now, how to manage software raids.
In this article we will learn about points,
1. Check existing software RAID configuration.
2. How to create a new RAID device.
3. Replacing a faulty device.
4. How to add device existing array.
5. Deactivating and removing an existing RAID device.
1. cat /proc/mdstat : All presently active RAID devices are stored in the /proc/mdstat file. With this command we can check our existing RAID type. It will show the list of devices.
2. mdadm –query /dev/md2 : To see more informaiton about the RAID device. To display more detailed information, use the following command,
# mdadm –detail /dev/md2
3. Steps to create new software raid device.
Make sure that your server is having two unused disk drives available,
# mdadm –create /dev/md2 –level=1 –raid-devices=1 /dev/sdc1 /dev/sdd1
4. Replacing a faulty device. To do so, first mark the /dev/sdb1 device as faulty:
# mdadm /dev/md2 –fail /dev/sdb1
Then remove it from the RAID device:
# mdadm /dev/md2 –remove /dev/sdb1
As soon as the hardware is replaced, you can add the device back to the array by using the following command:
# mdadm /dev/md2 –add /dev/sdb1
5. Extending a RAID Device
# mdadm /dev/md2 –add /dev/sdc1
# mdadm –grow /dev/md2 –raid-devices=2
6. Removing a RAID Device first deactivate it by running the following command as
#mdadm –stop raid_device
#mdadm –remove raid_device
7. Removing a RAID device
# mdadm –detail /dev/md2
First stop it by typing the following at a shell prompt before removing it
# mdadm –stop /dev/md2
After that you can remove it using command
# mdadm –remove /dev/md3
Introduction to Cloud Hosting In today's digital world, website performance can make or break an online business. Whether you run…
In the world of digital marketing, getting attention is only half the battle. The real goal is to convince people…
Introduction In today's digital world, understanding website bandwidth is essential for anyone running a website. Whether you own a blog,…
Artificial intelligence is changing the tech world at lightning speed. From automated chatbots to AI-generated applications, many people are now…
Introduction to Bot Traffic Bot traffic refers to visits to a website that come from automated software programs rather than…