Software raid mdadm

If you are using LVM then you can stretch and grow your partition over this new raid drive to give you more space. If you don't have space for three additional drives then you can also swap out the three 2TB drives with 4TB drives allowing the RAID to rebuild each time.

You should then be able to create a new second RAID using the unused space on the drives giving you the same options as the above option. Mdadm is for software raid. You said you had a hardware controller.

This is where you would alter your raid. Or you may have a host bus adapter fakeraid in which case you need dmraid instead of mdraid. As others said, use the hardware controller for this. On another note, you shouldn't be using RAID5 on large drives.

You have a high risk of losing everything on a rebuild after a drive failure. Actually, pretty much the opposite. I have done this many times. Hardware RAID on the other hand relies on the controller to format the drive and can often use proprietary formats. This isn't usually an issue as long as you can swap the controller with an identical one should it go bang.

If moving disks between systems to have to have the same model of controller in both locations. Statistic cookies help website owners to understand how visitors interact with websites by collecting and reporting information anonymously. Marketing cookies are used to track visitors across websites. The intention is to display ads that are relevant and engaging for the individual user and thereby more valuable for publishers and third party advertisers.

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Need help? Our experts have had an average response time of We will keep your servers stable, secure, and fast at all times for one fixed price. We can help you. To set up RAID, we can either use a hard drive controller or use any software to create it. Before going into the steps for configuring we will check the prerequisites for the setup.

Following are the prerequisites: 1. Then, in order to create an ext4 file system on RAID1 drive, we can run the following command: mkfs. We can use the following steps to recover a disk failure in RAID: Firstly we need to find out if the disc is damaged and needs to be replaced. When both disks are healthy, the output will be [UU].

To restore the array, we must remove the damaged disk and add a new one. RAID 6 is essentially an extension of RAID 5 that allows for additional fault tolerance by using a second independent distributed parity scheme dual parity. Even if two of the hard disk drives fail during the data recovery process, the system continues to be operational, with no data loss.

RAID 6 provides for extremely high data fault tolerance by sustaining multiple simultaneous drive failures. It handles the loss of any two devices without data loss. It requires a minimum of 4 devices. It is very slow in dual disk failure mode. Ensure that you modify the procedure to use your actual device nodes. Open a terminal console, then log in as the root user or equivalent. For example, at the command prompt, enter.

For example, at the command prompt enter:. The goal of this configuration is to improve the performance and fault tolerance of the RAID. Generally, this combination is referred to as RAID To distinguish the order of the nesting, this document uses the following terminology:. Because each member device in the RAID 0 is mirrored individually, multiple disk failures can be tolerated and data remains available as long as the disks that fail are in different mirrors. You can optionally configure a spare for each underlying mirrored array, or configure a spare to serve a spare group that serves all mirrors.

If multiple disks fail on one side of the mirror, then the other mirror is available. However, if disks are lost concurrently on both sides of the mirror, all data is lost. Also, if you lose the connection between the two sites, either site operates independently of the other. That is not true if you stripe the mirrored segments, because the mirrors are managed at a lower level.

If a device fails, the mirror on that side fails because RAID 1 is not fault-tolerant. Create a new RAID 0 to replace the failed side, then resynchronize the mirrors.

The procedure in this section uses the device names shown in the following table. Ensure that you modify the device names with the names of your own devices. At the command prompt, enter these two commands:. At the command prompt, enter the following command using the software RAID 1 devices you created in Step 2 :.

If a device fails on one side of the mirror, you must create a replacement RAID 0 device, than add it into the mirror. At the command prompt, enter the following command using the software RAID 0 devices you created in Step 2 :. Multiple copies of all data blocks are arranged on multiple drives following a striping discipline. Component devices should be the same size.

The far layout provides sequential read throughput that scales by number of drives, rather than number of RAID 1 pairs. Configure a spare for each underlying mirrored array, or configure a spare to serve a spare group that serves all mirrors. When configuring an complex RAID10 array, you must specify the number of replicas of each data block that are required. The default number of replicas is 2, but the value can be 2 to the number of devices in the array. You must use at least as many component devices as the number of replicas you specify.