Recently, write a plan, ready to introduce near-line storage in a new system.
Quote a little text, give you a reference:
LINK:
Http://tech.sina.com.cn/other/2003-12-29/1323275543.shtml
Nearline storage
-------------------------------------------------- ----------------------------- Traditional data stores are generally divided into online storage and offline (Off-line) ) Store two-level storage. The so-called online storage means that the data is stored on the disk system, and offline means backing up data to the tape. The advantages of the hard disk are fast, especially the random accessibility, but the unit capacity is high, and it is suitable for data storage that needs frequent access; the magnetic tape is good at transport streaming data, the characteristics separated by the medium and driver determine the cost of its unit capacity. Saving data is also high, suitable for data backups.
However, as the amount of data is so increased, this policy that only uses online and offline two-stage storage is no longer adapting to the needs of the company. On the one hand, users have more and more data still need access in a certain period of time. If back up to the tape, the speed of reading is too slow, and the online state is maintained, and it will occupy the precious of the accessed frequency. Storage space; on the other hand, the user requires "backup window" to get smaller and smaller, the backup device has a faster speed to shorten the backup time, and the base device is not enough compared to the disc-based device.
This creates a hierarchical storage management (HIERARCHICALSTORAGEMANAGEMENT, HSM). Hierarchical storage management is a technique that stores non-online storage and online storage. It determines the storage location at different stages of the data life cycle, thereby birth of a third storage method-line storage in the online storage and offline storage, so that the storage network from "online-offline" The two-stage architecture evolves to "Online-Nearline-Offline" three-level architecture. The near-line storage is characterized by the performance approaches online storage, and the cost is close to offline storage.
The near-line storage market has become a hot spot in the store field this year, and there are some products that use ATA hard drives as a near-line storage device. In recent years, the ATA (IDE) hard disk has achieved great development, and the capacity of a single hard disk is more than 2 times the SCSI hard disk, and the cost of the unit capacity is only 1/4 of the SCSI hard disk, which greatly reduces the gap between the tape, Performance is at least the same order with the SCSI hard drive.
In 2002, NetApp launched a NEARSTORER100 near-line storage device, gaining a huge success, with more than 100 users in the world, with a total deployment capacity of more than 3PB (1PB = 103TB). In February this year, NetApp released the second-generation NEARSTORE near-line storage device R150 in the world, and each of which has 24TB capacity, providing up to 430GB of backup data throughput of 430GB per hour.
Quantum launched a DX30 enhanced backup system last year, retaining compatibility with storage management software in the form of an emulatory tape library, and has higher read and write speeds than the tape library, and users can back up data into DX30, then Transfer to the tape. In May of this year, Quantum has introduced DX100 with unique compression technology to meet the backup and recovery requirements of key business databases and large distributed data centers. The initial local capacity can be extended from 6TB to 50TB, and increase hardware functions. And software features.
STORAGETEK companies with tape products introduced corresponding solutions provided by different life cycles of data, including tape devices and disk systems and software products to help users "will" appropriate data, in place, store to the appropriate device on". EMC has recently advocates information lifecycle management (ILM), and its core thinking is to use different storage strategies and storage media for different data, with different storage strategies and storage media, which is an important ring. In the data backup, use the proximal storage concept, with software to implement the organic combination of the disk with the tape, use a lower price disk as a replenishment of the backup device or the existing backup device, has become some vendors to start seeking solutions. LEGATO In this year's new NetWorker7.0, the first introduction of the disk and the magnetic band in combination of data backups, combines the disk fast access to the tape high-speed sequential order, and shields the online data saved by the disk is not safe enough. Slowness with tape recovery, greatly enhances the performance of backup and recovery. ADIC company has previously released a disk-tape backup solution PathlightVx, allowing users to back up their key data first to disk, then move to tape to narrow down the backup window.
The performance of the ATA hard drive is constantly increasing and its cost is much lower than the SCSI hard drive, making the near-line storage device based on the ATA hard drive become a focused area, with the rise of information life cycle management, the future, the near-line storage field will become An important part of data backup and data protection.
