Advanced Format (AF) is any
disk sector
In computer disk storage, a sector is a subdivision of a track on a magnetic disk or optical disc. Each sector stores a fixed amount of user-accessible data, traditionally 512 bytes for hard disk drives (HDDs) and 2048 bytes for CD-ROMs and D ...
format used to store data on magnetic disks in
hard disk drive
A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magnet ...
s (HDDs) that exceeds 512, 520, or 528 bytes per sector, such as the 4096, 4112, 4160, and 4224-byte (4
KB) sectors of an Advanced Format Drive (AFD). Larger sectors enable the integration of stronger
error correction
In information theory and coding theory with applications in computer science and telecommunication, error detection and correction (EDAC) or error control are techniques that enable reliable delivery of digital data over unreliable communica ...
algorithms to maintain data integrity at higher storage densities.
History
The use of long data sectors was suggested in 1998 in a technical paper issued by the National Storage Industry Consortium (NSIC) calling attention to the conflict between continuing increases in
areal density
The area density (also known as areal density, surface density, superficial density, areic density, mass thickness, column density, or density thickness) of a two-dimensional object is calculated as the mass per unit area. The SI derived unit is ...
and the traditional 512-byte-per-sector format used in hard disk drives.
Without revolutionary breakthroughs in magnetic recording system technologies, areal densities, and with them the storage capacities, hard disk drives were projected to stagnate.
The storage industry trade organization, International Disk Drive Equipment and Materials Association (IDEMA), responded by organizing the IDEMA Long Data Sector Committee in 2000, where IDEMA and leading hardware and software suppliers collaborated on the definition and development of standards governing long data sectors, including methods by which compatibility with legacy computing components would be supported.
In August 2005, Seagate shipped test drives with 1K physical sectors to industry partners for testing.
In 2010, industry standards for the first official generation of long data sectors using a configuration of 4096 bytes per sector, or 4K, were completed. All hard drive manufacturers committed to shipping new hard drive platforms for desktop and notebook products with the Advanced Format sector formatting by January 2011.
Advanced Format was coined to cover what was expected to become several generations of long-data-sector technologies, and its logo was created to distinguish long-data-sector–based hard disk drives from those using legacy 512-byte sector. Enterprise disks can be formatted with additional 8-byte
Data Integrity Field Data Integrity Field (DIF) is an approach to protect data integrity in computer data storage from data corruption. It was proposed in 2003 by the T10 subcommittee of the International Committee for Information Technology Standards. A similar appr ...
s, resulting in a 520 or 528-byte physical sectors.
Overview
Generation-one Advanced Format, 4K sector technology, uses the storage surface media more efficiently by combining data that would have been stored in eight 512-byte sectors into one single sector that is 4096 bytes (4 KB) in length. Key design elements of the traditional 512-byte sector architecture are maintained, specifically, the identification and synchronization marks at the beginning and the
error correction coding
In computing, telecommunication, information theory, and coding theory, an error correction code, sometimes error correcting code, (ECC) is used for controlling errors in data over unreliable or noisy communication channels. The central idea is ...
(ECC) area at the end of the sector. Between the sector header and ECC areas, eight 512-byte sectors are combined, eliminating the need for redundant header areas between each individual chunk of 512-byte data. The Long Data Sector Committee selected the 4K block length for the first generation AF standard for several reasons, including its correspondence to the
paging size used by
processors
A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, ...
and some
operating system
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs.
Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...
s as well as its correlation to the size of standard transactions in
relational database systems.
Format efficiency gains resulting from the 4K sector structure range from 7 to 11 percent in physical platter space. The 4K format provides enough space to expand the ECC field from 50 to 100 bytes to accommodate new ECC algorithms. The enhanced ECC coverage improves the ability to detect and correct processed data errors beyond the 50-byte defect length associated with the 512-byte sector legacy format. The Advanced Format standard employs the same ''gap'', ''sync'' and ''address mark'' configuration as the traditional 512-byte sector layout, but combines eight 512-byte sectors into one data field.
![Advanced format (4Kib) HDD sector](https://upload.wikimedia.org/wikipedia/commons/a/ae/Advanced_format_%284Kib%29_HDD_sector.svg)
Having a huge number of legacy 512-byte-sector–based hard disk drives shipped up to the middle of 2010, many systems, programs and applications accessing the hard disk drive are designed around the 512-byte-per-sector convention. Early engagement with the ''Long Data Sector Committee'' provided the opportunity for component and software suppliers to prepare for the transition to Advanced Format.
For example,
Windows Vista
Windows Vista is a major release of the Windows NT operating system developed by Microsoft. It was the direct successor to Windows XP, which was released five years before, at the time being the longest time span between successive releases of ...
,
Windows 7
Windows 7 is a major release of the Windows NT operating system developed by Microsoft. It was released to manufacturing on July 22, 2009, and became generally available on October 22, 2009. It is the successor to Windows Vista, released nearly ...
,
Windows Server 2008
Windows Server 2008 is the fourth release of the Windows Server operating system produced by Microsoft as part of the Windows NT family of the operating systems. It was released to manufacturing on February 4, 2008, and generally to retail on Fe ...
, and
Windows Server 2008 R2
Windows Server 2008 R2 is the fifth version of the Windows Server operating system produced by Microsoft and released as part of the Windows NT family of operating systems. It was released to manufacturing on July 22, 2009, and became General av ...
(with certain hotfixes installed) support
512e format drives (but not
4Kn
Advanced Format (AF) is any disk sector format used to store data on magnetic disks in hard disk drives (HDDs) that exceeds 512, 520, or 528 bytes per sector, such as the 4096, 4112, 4160, and 4224-byte (4 KB) sectors of an Advanced Format ...
),
as do contemporary versions of
FreeBSD
FreeBSD is a free and open-source Unix-like operating system descended from the Berkeley Software Distribution (BSD), which was based on Research Unix. The first version of FreeBSD was released in 1993. In 2005, FreeBSD was the most popular ...
and
Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which ...
.
Mac OS X Tiger
Mac OS X Tiger (version 10.4) is the 5th major release of macOS, Apple's desktop and server operating system for Mac computers. Tiger was released to the public on April 29, 2005 for US$129.95 as the successor to Mac OS X 10.3 Panther. Some ...
and onwards can use Advanced Format drives and
OS X Mountain Lion
OS X Mountain Lion (version 10.8) is the ninth major release of macOS, Apple Inc.'s desktop and server operating system for Macintosh computers. OS X Mountain Lion was released on July 25, 2012, for purchase and download through Apple's Mac Ap ...
10.8.2 additionally supports encrypting those.
Windows 8
Windows 8 is a major release of the Windows NT operating system developed by Microsoft. It was Software release life cycle#Release to manufacturing (RTM), released to manufacturing on August 1, 2012; it was subsequently made available for downl ...
and
Windows Server 2012
Windows Server 2012, codenamed "Windows Server 8", is the sixth version of the Windows Server operating system by Microsoft, as part of the Windows NT family of operating systems. It is the server version of Windows based on Windows 8 and succe ...
also support 4Kn Advanced Format.
Oracle Solaris
Solaris is a proprietary Unix operating system originally developed by Sun Microsystems. After the Sun acquisition by Oracle in 2010, it was renamed Oracle Solaris.
Solaris superseded the company's earlier SunOS in 1993, and became known for i ...
10 and 11 support 4Kn and 512e hard disk drives for non-root ZFS file systems, while version 11.1 provides installation and boot support for 512e devices.
Categories
Among the Advanced Format initiatives undertaken by the Long Data Sector Committee, methods to maintain backward compatibility with legacy computing solutions were also addressed. For this purpose, several categories of Advanced Format devices were created.
512 emulation (512e)
Many host computer hardware and software components assume the hard drive is configured around 512-byte sector boundaries. This includes a broad range of items including
chipsets
In a computer system, a chipset is a set of electronic components in one or more integrated circuits known as a "Data Flow Management System" that manages the data flow between the processor, memory and peripherals. It is usually found on the mo ...
,
operating system
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs.
Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...
s,
database engine
A database engine (or storage engine) is the underlying software component that a database management system (DBMS) uses to create, read, update and delete (CRUD) data from a database. Most database management systems include their own application ...
s, hard drive
partitioning and
imaging
Imaging is the representation or reproduction of an object's form; especially a visual representation (i.e., the formation of an image).
Imaging technology is the application of materials and methods to create, preserve, or duplicate images.
...
tools,
backup
In information technology, a backup, or data backup is a copy of computer data taken and stored elsewhere so that it may be used to restore the original after a data loss event. The verb form, referring to the process of doing so, is "back up", w ...
and
file system
In computing, file system or filesystem (often abbreviated to fs) is a method and data structure that the operating system uses to control how data is stored and retrieved. Without a file system, data placed in a storage medium would be one larg ...
utilities as well as a small fraction of other
software application
Software is a set of computer programs and associated documentation and data. This is in contrast to hardware, from which the system is built and which actually performs the work.
At the lowest programming level, executable code consists ...
s. In order to maintain compatibility with legacy computing components, many hard disk drive suppliers support Advanced Format technologies on the recording media coupled with 512-byte conversion firmware. Hard drives configured with 4096-byte physical sectors with 512-byte firmware are referred to as Advanced Format 512e, or 512 emulation drives.
![afdiag3](https://upload.wikimedia.org/wikipedia/commons/7/74/Afdiag3.jpg)
The translation of the native 4096, 4112, 4160, or 4224-byte physical format (with 0, 8, 64, or 128-byte
Data Integrity Field Data Integrity Field (DIF) is an approach to protect data integrity in computer data storage from data corruption. It was proposed in 2003 by the T10 subcommittee of the International Committee for Information Technology Standards. A similar appr ...
s) to a virtual 512, 520 or 528-byte increment is transparent to the entity accessing the hard disk drive. Read and write commands are issued to Advanced Format drives in the same format as legacy drives. However, during the read process, the Advanced Format hard drive loads the entire 4096-byte sector containing the requested 512-byte data into memory located on the drive. The emulation firmware extracts and re-formats the specific data into a 512-byte chunk before sending the data to the host. The entire process typically occurs with little or no degradation in performance.
The translation process is more complicated when writing data that is not a multiple of 4K or not aligned to a 4K boundary. In these instances, the hard drive must read the entire 4096-byte sector containing the targeted data into internal memory, integrate the new data into the previously existing data and then rewrite the entire 4096-byte sector onto the disk media. This operation, known as
read-modify-write (RMW), can require additional revolution of the magnetic disks, resulting in a perceptible performance impact to the system user. Performance analysis conducted by IDEMA and the hard drive vendors indicates that approximately five to ten percent of all write operations in a typical business PC user environment may be misaligned and a RMW performance penalty incurred.
When using Advanced Format drives with legacy operating systems, it is important to realign the disk drive using software provided by the hard disk manufacturer. Disk realignment is necessary to avoid a performance degrading condition known as ''cluster straddling'' where a shifted partition causes filesystem clusters to span partial physical disk sectors. Since cluster-to-sector alignment is determined when creating hard drive partitions, the realignment software is used ''after'' partitioning the disk. This can help reduce the number of unaligned writes generated by the computing ecosystem. Further activities to make applications ready for the transition to Advanced Format technologies were spearheaded by the ''Advanced Format Technology Committee'' (formerly ''Long Data Sector Committee'')
and by the hard disk drive manufacturers.
4K native (4Kn)
![Advanced Format 4Kn logo](https://upload.wikimedia.org/wikipedia/commons/5/5d/Advanced_Format_4Kn_logo.png)
For hard disk drives working in the ''4K native'' mode, there is no emulation layer in place, and the disk media directly exposes its 4096, 4112, 4160, or 4224-byte physical sector size to the system firmware and operating system. That way, the externally visible logical sectors organization of the 4K native drives is directly mapped to their internal physical sectors organization. Since April 2014, enterprise-class 4K native hard disk drives have been available on the market.
Readiness of the support for 4 KB logical sectors within operating systems differs among their types, vendors and versions.
For example,
Microsoft Windows
Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...
supports 4K native drives since
Windows 8
Windows 8 is a major release of the Windows NT operating system developed by Microsoft. It was Software release life cycle#Release to manufacturing (RTM), released to manufacturing on August 1, 2012; it was subsequently made available for downl ...
and
Windows Server 2012
Windows Server 2012, codenamed "Windows Server 8", is the sixth version of the Windows Server operating system by Microsoft, as part of the Windows NT family of operating systems. It is the server version of Windows based on Windows 8 and succe ...
(both released in 2012) in
UEFI
UEFI (Unified Extensible Firmware Interface) is a set of specifications written by the UEFI Forum. They define the architecture of the platform firmware used for booting and its interface for interaction with the operating system. Examples of ...
.
Linux supports 4K native drives since the
Linux kernel
The Linux kernel is a free and open-source, monolithic, modular, multitasking, Unix-like operating system kernel. It was originally authored in 1991 by Linus Torvalds for his i386-based PC, and it was soon adopted as the kernel for the GNU ope ...
version 2.6.31 and version 2.17 (released in 2009 and 2010, respectively).
The color version of the logo indicating a 4K native drive is somewhat different from the 512e logo, featuring four rounded corners, a blue background, and text "4Kn" at the center of the logo.
See also
*
Partition alignment Partition alignment is the proper alignment of partitions to the boundaries available in a data storage device.
Examples include the following:
* 4 KB sector alignment with hard disk drives supporting Advanced Format (AF)
* Track partition a ...
References
{{Reflist
External links
IDEMA: Advanced Format Technology(archived on September 29, 2011)
Coughlin Associates: Aligning with the Future of Storage(archived on May 5, 2012)
Western Digital: Advanced Format White Paper(September 2018) and it
older version(April 2010)
Hitachi Global Storage Technologies: Advanced Format Technology BriefThe Tech Report: Western Digital brings Advanced Format to Caviar GreenDell: Support: System Image Support for Advanced Format Hard Drives on Dell Business Client Notebooks and Desktops
Hard disk drives
Solid-state computer storage