Self-certifying File System (SFS)

To reduce request fragmentation for large requests, Self-certifying File System (SFS) bypasses the Windows buffer cache and tries to make one request for the entire amount of data.

The SFS accesses hard disks by addressing entire extents, which are flexibly-sized groups of blocks. With a good disk allocator such as ours, extent-based file systems minimize fragmentation. For example, say Windows makes 64 KB requests for buffered I/O, which results in eight I/O requests for 8 KB blocks. The SC101 SFS allocator, in comparison, searches chunks of thirty-two 8KB blocks (before moving to sixteen 8KB blocks, before finally moving to eight 8KB blocks). Often files are larger than the maximum Windows request size, so Windows’ files will fragment. SFS avoids the fragmentation of Windows. The SFS allocator can use both first-fit and best-fit algorithms, and typically outperforms Windows in terms of maximum blocks that can be transferred at a time. All this makes it easy for the SC101 to stay “defragmented”, using its own software.

Another non-Windows feature that reduces SC101 disk accesses is stuffed dinodes. In the Windows NTFS disk management, the addresses for blocks are stored in a different place than the blocks, themselves. This means that any request for NTFS disk data, no matter how small, causes two I/O operations. Since hard disk I/O is far slower than your CPU or RAM, doubling the amount of I/O can have a noticable impact on performance. Since SFS can store both the address and the data in the same extent, the amount of I/O for very small files is cut in half.

New Technology File System (NTFS)

With conventional disk management such the NTFS used by Windows, disks are divided into small, equally-size divisions called clusters; disk access is made for clusters, and a file may use many clusters. This old practice is suited for programs with limited needs for disk performance, or for low-level programs that handled their own disk access. Unfortunately, neither of these is true of many modern software applications.

To reduce request fragmentation for large requests, Self-certifying File System (SFS) bypasses the Windows buffer cache and tries to make one request for the entire amount of data. See Self- certifying File Systems (SFS).

SAN and Network Attached Storage (NAS)

The SC101 is a SAN device. SAN disks run as an extension of a computer's operating system. Computers that use the SC101 must have operating systems and software that are compatible with the SAN.

A NAS is a more complicated device that has its own, small operating system. Sometimes computers that have been converted just to be file servers are referred to as NAS devices.

Both technologies create disks that are accessed directly by many computers over a network. The computers share the network resource. This reduces maintenance in large systems, and also avoids having a single computer tied up answering requests for its data from all over a network.

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NETGEAR SC101 manual Self-certifying File System SFS, New Technology File System Ntfs, SAN and Network Attached Storage NAS
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SC101 specifications

The NETGEAR SC101 is a network-attached storage (NAS) device designed to simplify data storage and sharing within a home or small office environment. It provides an efficient solution for users looking to centralize their files, making them accessible from multiple devices connected to the same network.

One of the main features of the SC101 is its user-friendly interface that allows for easy setup and administration. It supports Windows, Mac OS, and Linux operating systems, ensuring compatibility with a wide range of devices. This versatility makes it an attractive choice for households and small businesses that utilize different systems. The SC101 also implements a simple drag-and-drop file management system, enabling users to effortlessly store and retrieve their data.

The device is built with two bays, accommodating standard hard drives that can be customized based on the user's storage needs. This flexibility enables users to start with a single drive and expand their storage capabilities as required. The SC101 supports both RAID 0 and RAID 1 configurations, allowing for a balance between performance and data redundancy. RAID 0 offers enhanced speed, while RAID 1 mirrors data, providing a level of protection against drive failures.

Connectivity is another highlight of the SC101. It features an Ethernet port that connects to the network, with support for various protocols including TCP/IP and UDP. Users can access their files from any computer on the network or even remotely, providing enhanced accessibility for team collaboration or personal use. The built-in web-based management interface also enables users to manage user accounts and permissions, ensuring security and controlled access to data.

In terms of performance, the SC101 utilizes a 480 MHz processor and 64 MB of RAM, which helps in delivering satisfactory performance for file transfers. While it may not compete with modern storage solutions or high-speed drives, it facilitates efficient data retrieval suitable for home and office environments.

Overall, the NETGEAR SC101 is a practical NAS solution that combines central file storage, easy management, and essential data protection features. Its compatibility with various operating systems, support for RAID configurations, and user-friendly setup make it a solid choice for users seeking to enhance their data storage capabilities without the complexity often associated with high-end NAS systems.
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