Disk management 5

Soft RAID

I. Concepts

The stored data is separated and stored, and then staggered and stored on all disks that constitute the array.

1. The data read and write speed is greatly improved, but the read and write speed is lower than the total read and write speed of all disks.

2. the available space is the sum of all disk spaces.

3. data redundancy is not provided.

 

The disk stores the same data and provides data redundancy.

1. The available space is equal to the minimum disk space of the array disk.

2. Data Reading and Writing cannot be accelerated.

3. Each disk has the same data, usually called an image volume.

 

 

RAID 5 does not separately specify a parity disk. Instead, it accesses data and parity information across all disks. On RAID 5, read/write pointers can be performed on the array devices at the same time, providing higher data traffic. RAID 5 is more suitable for small data blocks and random read/write data. The main difference between RAID 3 and RAID 5 is that each data transmission of RAID 3 involves all array disks. For RAID 5, most data transmission only operates on one disk and can be performed in parallel. There is a "Write loss" in RAID 5, that is, each write operation will generate four actual read/write operations, two of which read the old data and parity information, write new data and parity information twice.

1. provide redundancy.

2. Reading and Writing disks at the same time speeds up data reading and writing.

3. You need to perform the parity operation to consume computing resources.

4. Available space is N * (M-1) N represents disk space, M represents the total number of disk arrays.

2. Create RAID

1. RAID 0

2. RAID 1

3. RAID 5

Iii. View

1. RAID 0

2. RAID 1

3. RAID 5

Iv. Configuration File

Mdadm -- detail -- scan indicates that the disk array is scanned and corresponding information is written to the configuration file.

5. Format mounting

Looking at the following results, I want to cry. (Virtual Machine experiments can only prove the feasibility of the method, but the performance needs to be tested on a real machine)

6. Add and use a backup disk

1. RAID1 and RAID5

2. View

RAID1

RAID5 same as above

2. RAID5 analog data

3. Use a backup disk

4. View

Mark vdd2 as a fault

7. Disable the disk array

1. Simulate data

2. Disable the disk array.

Equivalent

3. Enable

Zookeeper