What is maid storage?

What is maid storage?

Maid, that is, massive arrays of idle disks. Snia defines maid as a storage system comprising an array of disk drives that are powered down individually or in groups when not required. Maid storage systems reduce the power consumed by a storage array.

Maid technology is proposed and developed based on the working mode of the tape library. The working principle of the tape library is that all the tapes are placed in the slot of the tape library under normal conditions, and they need to be placed in the tape drive only when a disk is needed, and then read and write data. Most of the time, most tapes are not working. Maid applies the same principle. Only when necessary can some disks be started, while other disks are usually in the power-off status, just like tapes in the tape library. Therefore, the disk storage of the maid technology can also be called a disk library.

Maid greatly satisfies the green, environmental, and energy-saving features of the popular "green storage". All disks in the storage device are not active and power on every moment, most hard disks are in the power off status. The hard disk will be powered on again only when the system requires read/write access. The start time of the SATA hard disk in maid storage is about 10 seconds. After a hard disk in the power on status has been idle for a certain period of time (which can be pre-set based on the system access characteristics and frequency), it is switched to the power off status according to the policy, in order to achieve the node, environmental protection, extend the hard drive service life function.

Taking nexsan's automaid as an example, the maid node function operates in three stages. The time interval of each stage can be customized by the user.

If the data is not read within two minutes, the hard disk head will remain in the area where data is not accessed to save power consumption. If the data is not read after 10 minutes, it will enter the second stage, and the hard disk will speed down to 4000 rpm. If the data is still not read after 15 minutes, it will enter the third stage, and the hard disk will stop running, wait until the system calls start again, but the hard disk is still in the power-on status, so it is still in the "prepare" status, and the restart time is about 10 ~ 15 seconds.

Maid Storage features

Maid (massive arrays of idle disks) technology makes maid storage devices have several important functions and features:

• The disk or disk raid group in the maid storage system can be powered off based on the policy when no read/write access is available;

• The power-off disk automatically checks Faults Based on policies;

• After the disk is powered off, once a read/write request is sent, the disk is automatically powered on, And the raid group can re-provide normal access;

• Reduces energy consumption and saves energy by 30%;

• Reduce environment and management costs;

• Longer disk service life.

Storage devices with the maid function can greatly save energy consumption, especially in large data centers or data warehouse systems, which can reduce the pressure on the power supply system of data centers.

The maid function can be used to stop high-speed Disk disk rotation and stop disk movement when the disk is not accessed. This effectively prolongs the service life of the disk. The maid function effectively reduces the probability of SATA disk corruption, especially in high-capacity storage systems with low security and stability, reduce the overall data loss caused by damage to multiple disks in the raid group.

Maid Storage Products

Maid storage actually exists a few years ago, but it is hard to attract attention and attention. Now, on the premise that the world advocates "Green, energy-saving and environmental protection", especially after "snw 2007" proposes the concept of green storage, maid has been re-mentioned on the desktop, there is also a trend that will become an important part of the concept of "green storage.

Copan and nexsan are early developers of maid storage technology. In the past year, many storage manufacturers have begun to invest in this technology. Fujitsu (Fujitsu) joined the technology for the first time in last year's new storage product eternus8000/4000. The new NEC storage D series also adopted the maid technology. In addition, other storage vendors are also optimistic about the future of maid-based technologies, and are expected to publish storage products based on this technology before the end of the year.

Copan's patented disk aerobic software continuously monitors all running drives and regularly detects idle disks to ensure that all disks in the system are healthy within the scope of design metrics. If a disk is found to be faulty, the disk aerobic software will replace it with a backup disk and withdraw it from the system. This greatly reduces the probability of re-raid due to disk failure, thus eliminating the possibility of re-error of the second disk before raid recovery. The software also performs a routine data check every month. If any error message is found on the disk or cannot be read, the data will be corrected to ensure that the data can be read at any time in the future.

Maid Storage Solution

IDC green energy-saving solution

With the continuous development of network, information and data, the servers and storage data of large data centers are very large. The average power consumption of servers and storage accounts for 50% and 40% of the total power consumption of data centers. The power consumption of data centers has become an important expense for daily operations of data centers. How to save energy and reduce the operation costs of data centers has become an important trend.

The energy efficiency of maid storage varies according to the application characteristics of business systems, and the average energy efficiency can reach 25-30%. A large number of maid storage in the data center can greatly save energy and reduce the operation cost of the data center.

Based onVTL + maidData backup storage solution

Data backup systems such as database systems and email systems generally aim to recover data when data is lost. As long as the online business system is secure and stable, except for one or more data backup operations per day, the backup system is basically idle. The usage of this device is exactly the same as that of maid storage.

The database backup system adopts the maid storage and combines the high-performance VTL virtual tape library software, it can not only realize the efficient and fast D-D data backup and data recovery between the online system and the backup system, reduce the data backup window, to ensure the normal operation of the business system and the rapid recovery after the fault, you can also effectively reduce the power consumption and the failure probability of the hard disk when the backup system is idle, this greatly improves the security of backup data.

Based onCDN + maidVideo website Storage Solution

Large-scale IPTV, video download, on-demand video streaming, and more popular podcast systems generally store programs with thousands, tens of thousands, or even hundreds of thousands, or millions of hours, most of these programs are important media assets that need to be preserved for a long time. With the development of the system, the program volume will increase, and the capacity of storage devices used to store video files will increase.

We know that although the number of programs in the video/audio application system is large, it is generally divided into popular and non-popular types based on the click rate. CDN (Content Delivery Network) the system distributes different audio and video files to multiple storage devices or one storage path based on the predefined CTR change policy. Frequently accessed popular audio and video files can be stored on high-performance storage devices, while a large number of non-popular audio and video files can be stored on the energy-saving maid storage. Maid technology can store a large number of non-hotspot audio and video storage for energy saving, thus reducing the operating costs of the system.

Based on Storage Policy+ MaidVideo Monitoring Storage Solution

With the establishment of China Telecom's "Global eye", China Netcom's "Wide World", and the "Safe City" video surveillance system systems in various cities, there are more and more storage devices used for video surveillance systems, the capacity of storage devices in the system is also growing.

Video surveillance system design specifications require that video images collected from various monitoring sites must be stored online for 10-15 days or even 30 days before they can be deleted. For storage devices, if a monitoring site does not have any abnormal conditions, the video image files collected from the monitoring site, from the start of writing to the deletion of this long period of time is generally not accessed. If this part of the video image file storage device stores maid storage, it can greatly save energy consumption and achieve green environmental protection and energy saving functions.

Assume that the video monitoring system is configured with 15 storage volumes as required by capacity. We can design a storage policy for the monitoring system management platform and set the first day's image files to be stored in the first volume, the image files of the next day are stored in the second volume, and so on. 15 storage volumes can be used to store image files for 15 days. According to this storage policy, the entire maid storage system can ensure that all image files are online in real time, but at any time, only the hard disk corresponding to a volume is in the power on state, the remaining fourteen volumes are all in power off, which minimizes power consumption and reduces the operating costs of the monitoring system. In addition, it can avoid high-frequency damage caused by working hours on all hard disks.

More solutions

To further achieve the goal of green and energy-saving storage, maid storage can also use more advanced and low-energy processing chips to reduce the power consumption of each hard disk. Combined with data lifecycle management, reduce the number of high-power disks (15,000 GB, 750 GB, 7,200 GB, and GB). Combined with the deduplication technology, this reduces the total demand of hard disks, to achieve the best green and energy-saving effect.

Maid Storage application environment

The principle of maid storage is to make the hard disk with no access request for a long time in the power off state, in order to save energy and prolong the hard disk life, therefore, maid storage is suitable for large-capacity nearline storage (nearline storage) devices with low access frequency and real-time data availability requirements, it is especially applicable to data backup, data archiving, and other applications for data recovery purposes. It is not suitable for high-performance real-time access systems or application systems with low access interval.