What is a near-line hard disk and what are its benefits

In the era of big data, safe and long-term storage and management of data is a major challenge faced by many enterprises. Traditional storage strategies require the construction of large data center systems, leading to rising storage costs. Today, let’s talk about what near-line hard drives are and what benefits near-line storage technology has for the development of hard drives.

1、 What is a near-line hard disk

NearStore is a concept proposed with the refinement of customer storage environments;

The so-called near-line storage has a relatively broad extension and is mainly positioned for applications between customer online storage and offline storage. It refers to storing data that is not frequently used or that has a small amount of access to data on storage devices with low performance. But at the same time, the requirements for these devices are fast addressing and high transmission rate. (For example, the archiving of customer files that have been stored for a long time and are not used for a long time). Therefore, near-line storage requires relatively low performance requirements, but also relatively good access performance. At the same time, in most cases, because infrequently used data accounts for a relatively large proportion of the total data volume, this requires a relatively large capacity of near-line storage devices.

Traditionally defined near-line storage devices in the industry are mainly DVD-RAM optical towers and optical library devices. However, with the continuous development of storage devices, we will also use low-end disk arrays (such as DS4100) or high-end tape devices (such as 3592) as near-line storage application devices, depending on customer storage requirements.

What is a near-line hard disk and what are its benefits

2、 What is near-line SATA storage?

Nearline SATA refers to a type of near-line storage device. Nearline storage refers to storing data that is not frequently used or has a small amount of access to data on storage devices with lower performance. There is a corresponding near-line storage device, but it can also be understood as a behavior and a storage method. For example, using a relatively low performance hard disk as a warehouse disk to store data with low usage frequency can be referred to as near-line storage.

If you are using a SATA hard disk for near-line storage, but because the performance requirements for the hard disk are relatively lower when using near-line storage, you can use a relatively slower interface as a near-line transmission interface, such as SATA1, or a slower SATA2 interface than SATA3, or a SATA3 interface obtained using a bridge chip, leaving the native SATA3 interface with faster speed and better performance to the primary hard disk and the hard disk that is used more frequently. At this point, the interface used for near-line storage can be referred to as near-line SATA. Burning optical disks and mobile hard disks used as warehouse disks can be understood as near-line storage.

3、 What is Nearline SAS Storage?

Nearline SAS is actually one of the near-line storage devices, which is now relatively popular and used to be basically optical disks and the like. Nearline storage refers to storing data that is not frequently used, or that has a small amount of data access, on storage devices with lower performance. But at the same time, the requirements for these devices are fast addressing and high transmission rate. (For example, the archiving of customer files that have been stored for a long time and are not used for a long time). Therefore, near-line storage requires relatively low performance requirements, but also relatively good access performance. At the same time, in most cases, because infrequently used data accounts for a relatively large proportion of the total data volume, this requires a relatively large capacity of near-line storage devices.

4、 What is offline storage?

A concept corresponding to near-line storage, “offline storage,” refers to the backup of online storage data to prevent possible data disasters. Data stored offline is not often called and is generally remote from system applications, so people use “offline” to dynamically describe this storage method. Data on offline storage media is read and written sequentially. When it is necessary to read data, the tape needs to be rolled to the end and then positioned. When it is necessary to modify the data that has been written, all data needs to be overwritten. Therefore, offline storage access is slow and inefficient. A typical product for offline storage is a tape library, which is relatively inexpensive.

5、 What are the advantages of near-line storage

Nearline, using its standard storage interface, can start data transmission within 3 seconds. This makes a significant difference in how quickly data can be restored to online state during disaster recovery, and also makes the recovery of individual files or directories more attractive and interactive.

In addition, Nearline’s multi site redundant storage provides data integrity and disaster protection, and uses the same interface as other storage services.

Nearline provides a bandwidth speed of 4M/second per terabyte of storage, and the speed will increase as the storage capacity increases. Although this may become a major concern for small businesses choosing Nearline, both medium-sized and large enterprises have larger capacity archives, so they are not so concerned about bandwidth issues.

6、 Current Status of Nearline HDD

Nearline storage is generally used by enterprises that need to store large amounts of data but do not often use it, such as online disk companies. Toshiba’s disk is equivalent to WD’s Se series or Seagate’s CS series, both of which belong to Enterprise Value, lower than the level of dense data centers. The popular expression for data is that a RE level design can process 550 TB of data per year with an MTBF of 140 W hours, while an SE level design can process 550 TB of data per year with a reduced MTBF of 100 W hours.

The near-line storage market has become a hot spot in the storage field this year, with the emergence of some products using ATA hard disks as near-line storage devices. In recent years, ATA (IDE) hard disks have made significant progress. The capacity of a single hard disk is more than twice that of SCSI hard disks in the same period, while the cost per unit capacity is only 1/4 that of SCSI hard disks, greatly narrowing the gap with tape, and the performance is at least the same order of magnitude as SCSI hard disks.

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