Pilot project: Configuring disk Arrays (RAID 0, RAID1, RAID5, Raid6, raid1+0)
Theoretical part:
Multiple separate physical disks are grouped together in different ways, and then a logical disk is formed, which provides more storage efficiency and capacity, data security than a single physical disk, and RAID levels, with different levels of raid making different tradeoffs between read-write, storage, and data backup. In the actual application is generally divided into several
RAID0: Called striped storage, it has a high transfer rate, but no data redundancy. As long as one of the disks is damaged, all the data will be affected, so it can't really be a raid
RAID1: Known as mirrored storage, it is data redundancy through data mirroring. Features: Slow write speed, fast reading, high data security, low disk utilization (the capacity to use is half the total capacity of the disk), so it is expensive to use. Must use more than 2 block disk combinations
RAID5: It can be seen as a combination of RAID0 and RAID1. It must be combined with 3 or more disks, which is equivalent to holding a disk to store parity information. So when one of the disks is damaged, the data is recovered from the disk that stores the parity, which guarantees the security of the data. So the performance of its writing is relatively low. This is typically used in data centers
RAID6: It is similar to the RAID5 concept, except that it must be composed of 4 or more disks, which is a second independent storage parity information with two disks, so this raid can break 2 disks. This will make the write performance is not high, but relative to the security of the data increased a lot. But disk utilization has also dropped a lot. Therefore, the fish and bear cake can not be combined.
Raid1+0: It is the combination of RAID1 and RAID0. Generally first do RAID1 in RAID0. This security is better than raid 0+1. It's similar in read and write performance, but better in safety.
The next Test:
Here you choose to RAID5 for example, add 4 disks to the VMware virtual machine, make the 4 disks into RAID5, it is important to note that since we are doing raid, the format needs to go (ID:FD).
1. Add a new four HDD first:
2. Next, partition the newly added four hard drives as shown in fdisk-l to view the partition information:
3. Next use rpm-q Mdadm to see if the tool that manages the raid is installed. Down we can combine these 4 disks into a RAID5. For example:
4. Use mdadm-d/dev/md1 to view disk array information:
5. Then format the RAID5 and create an empty directory to mount it:
By this RAID5 configuration is complete, the test succeeds!
Configuring the disk array under Linux RAID5
