Category Archives: Storage

File Storage Using a Network-Attached Storage (NAS)

NAS, or Network-Attached Storage, is a type of computer file storage. It is connected to a network of computers that allow data access to a network of clients.

History of the NAS

In 1983, NAS was introduced as an early file-sharing system for a particular server operating system and an NCP protocol. The following year, Sun Microsystems, Inc. released the NFS, which allowed the sharing of storage space among clients within a network server.

Microsoft, together with 3Com, then developed the LAN Manager Protocol and software. More companies followed in creating file servers. By 2000, several start-ups emerged in an effort to offer alternatives for single files. This was when NAS was introduced.

What is a Network-Attached Storage?

A unit of NAS is basically a self-contained computer that is connected to a network. Its single purpose is to provide file-based data storage for other devices within a network. Within the NAS units are operating systems and other software that enable storage functionality. There are also management procedures for these functionalities.

NAS does not perform computing tasks, but users can run software in it. Also, a NAS lacks keyboard and display. It can only be configured and controlled through the network by connecting a browser to a network address.

If you do not have NAS in your network, you can use the computer as a file server. A file server works the same as a NAS unit. The difference is a file server has a keyboard, display, and an operating system. This makes it possible to store data and run other tasks as well. However, NAS is preferred for storage because file servers are also being developed for other functions, such as e-mail and database services, among others.

Pros and Cons

If you have a built-in RAD and clustering, then you can increase available data while using NAS. You can also increase the performance of a NAS when it is also used as a file server. There are also other factors to consider, such as the speed and amount of traffic within a network. Remember that NAS may have a server in it, with components similar to those of a PC.

NAS has quite a few limitations as compared to other storage systems like DAS/FC. These limitations are the result of a reduced operating system and CPU layer, too many users in the network, or extremely demanding processing power.

For more information on Network attached storage read:

  • Network Attached Storage
  • Network Attached Storage
  • SCSI to USB

    The birth of the Universal Serial Bus (USB) revolutionized the computer-wiring system. Most modern computers have USB terminals, and the majority of wiring and memory storage devices have USB capability.

    The Small Computer System Interface (SCSI) is not completely obsolete, but many users prefer USB devices for ease in connectivity. USB is a standard for interface devices. This system uses a universal socket interface boosting the plug-and-play features of the computer to its maximum level.

    USB has many characteristics that earned the preference of many computer users. One thing that sets it apart from other devices is that it does not need to consume so much energy to perform all its functions. No batteries or chargers necessary just plug it on any USB port and it will do its work. USB may also be popular because connecting and disconnecting peripherals no longer require the computer to reboot.

    Another good thing about the USB device is its flexibility and adaptability. There is no need to install specific device drivers to make USB work with computers. The speed and accuracy of the device depends on the computer system capabilities. A large percentage of computer peripherals now use this technology, including digital cameras, joysticks, keyboards, mouse devices, personal digital assistants (PDAs), printers, and scanners.

    Personal computers using older SCSI terminal standard can be made compatible with the current USB technology following these three steps:

    • Purchase an SCSI-to-USB adapter to facilitate connection from the SCSI terminal to the USB terminal.
    • Connect the adapter’s SCSI component to the computer’s SCSI terminal to mediate between the computer and the peripherals.
    • Plug the USB device into the USB-designated component in the adapter.

    This gives the convenience of the USB system to SCSI-enabled computers. The driver software will automatically detect the connection, making the peripherals operate as expected.

    For more information on SCSI to USB read:

  • SCSI to USB
  • SCSI to USB
  • iSCSI

    Internet Small Computer Systems Interface (iSCSI) is a standard for transmitting SCSI commands and information through IP networks. This type of protocol permits clients (called initiators) to convey SCSI commands to SCSI storage devices (also called targets) in remote servers.

    A widely used Storage Area Network (SAN) format allows entities to merge storage in data center arrays while giving hosts (like Web and database servers) the semblance of disks that attach locally. iSCSI can operate over long distances using pre-existing infrastructures, unlike Fibre Channel which needs special cabling.

    How iSCSI Runs

    As an application tries to read an iSCSI device, an IP packet encloses the read command. The packet sent arrives like any IP packet in the network. Upon arriving at its destination, the read command is revealed and decoded by the iSCSI device.

    Initiators and Targets

    ‘Initiator’ and ‘target’ are terms used to describe iSCSI clients and servers. An ‘initiator’ is the client, like a database server accessing data through remote storage. A ‘target’ is a storage server providing the data.

    iSCSI Alternatives

    iSCSI’s closest competition is Fibre Channel over Internet Protocol (FCIP). iSCSI is the use of SCSI with IP hardware, while FCIP is the use of IP with Fibre Channel hardware.

    iSCSI mostly operates as Cleartext protocol with no cryptographic protection. This is unsafe, as transmitted data in SCSI transactions have no cryptographic protection.

    Due to this, any malicious user who ‘eavesdrops’ on iSCSI traffic can:

    • Recreate and copy file systems and files being transmitted through the wire
    • Modify file content by introducing invalid iSCSI frames
    • Corrupt file systems that are being accessed by initiators, thus exposing servers to software error

    HVD

    HVD stands for Holographic Versatile Disc. It is known as the next generation product in optical discs technology. Once produced, HVD would have around 3.9 terabytes of storage capacity and a 1 GB/s data transfer rate. These specifications are considerably higher than those of HD DVD (High Definition Digital Versatile Disc) and the Blu-Ray disc. HVDs can also store 60,000 bits per pulse. This is a huge improvement from traditional CDs that can save only 1 bit per pulse.

    HVD uses a set of advanced technologies and procedures. It uses collinear holography, a technique wherein a blue-green laser ray and a red laser ray are paralleled to form one beam. The blue-green laser ray reads data on the holographic surface. The red laser ray serves as the reference beam and it also reads information on the aluminum top of the disc.

    HVDs have dichroic mirrors located between the disc’s layers. These mirrors reflect the blue-green laser ray. In this procedure, the red laser ray would be able to pass through and access the information it needs to read. Through this technique, the interference problem caused by the blue-green ray’s refraction is eliminated. The said problem is common in most holographic devices.

    Upon its full commercial release, HVD is expected to cost around $100 to $120 per disc. HVD readers would cost around $10,000 to $15,000. These prices would, however, vary depending on the competing technologies and overall public reception. The initial markets which are targeted by the HVD technology are government agencies, document libraries, and large businesses.

    Mirroring

    Mirroring is the process of automatically writing data to two storage devices simultaneously. This technique is applied in certain work places that constantly require multiple backups of files and folders. Mirroring is applied in more technical procedures such as RAID (Redundant Array of Independent Disks).

    The main purpose of mirroring is to provide redundancy. When one of the two storage devices fails, the redundant storage device will continue to copy the data. Hence, the user will still be able to access the data in spite of the disk failure. After the copying process, the device that failed can be replaced with a new one, and the device that has been set can be re-mirrored.

    Mirroring can be implemented in both hardware and software. Hardware devices carry out the mirroring process on the I/O controller of the host computer. In this case, the I/O controller solely takes the task of writing the data twice. It should be noted though that if the I/O controller fails, it must be replaced before the user can access the data.

    An external storage device can also perform mirroring. Here, the host is not in any way involved in the said process. Unlike mirroring that involves the I/O controller, the external storage device manages the entire mirroring process.

    Mirroring can also be done in software. This process requires the computer to write the mirrored data two times. This enables the user to access multiple copies of one software, which is appropriate for program testing. Although software mirroring is generally less expensive than hardware mirroring, the former entails the higher use of resources.

    WWN

    The World Wide Name (WWN) is the 64-bit address given to a single element in a specific Fibre Channel Network. This distinguishes an element of the network from one another.

    How does WWN operate?

    The WWN is an 8-byte number. The first 3 bytes are from the 24-bit OUI (Organizationally Unique Identifier) number purchased from the IEEE (Institute of Electrical and Electronics Engineers). The vendor supplies the remaining bytes of information to complete the WWN.

    WWN’s Formats

    1. The Original Format – addresses allocated to the IEEE standards that the committee set up and made into a device built in a given time –this is parallel to the Ethernet Mac address. The first 2 bytes are the vendor identifier that has 3 bytes and the next 3 bytes is a serial number specified by the vendor.
    2. New Addressing Schema – is the first-ever half byte followed by the vendor identifier’s 3-byte and the 4-byte and half for the serial number, which the vendor specifies.

    What is a Fibre Channel?

    It is gigabit-speed network technology mainly used for storage networking. The T11 Technical Committee of the IICITS, an ANSI-accredited standards committee regulates the Fibre Channels. The Fibre Channels are those that use the WWN to cite the different elements in their given Channel Network.

    What is Soft Zoning?

    Soft Zoning is the process used by switches on Fibre Channels to prevent ports from being seen outside their own zones. There is, however, a security risk attached in soft zoning. The ports can become accessible if a user in a different zone correctly gets the fibre channel address. Although very risky, the WWN still assigns soft zoning to maintain its processes.

    What is WWN Zoning?

    WWN zoning is the usage of name services in switches to either allow or stop access to a given World Wide Names in its framework. One major advantage of zoning is its ability to re-cable the structure without repeating the process of creating the zone information.

    Convert FAT32 to NTFS

    To be able to convert a FAT 32 file system into an NFTS, it requires a built-in utility in your Windows operating system. Windows and other programs do not have a tool that will successfully convert NFTS to FAT 32. So, before moving on with the process, you need to consider it closely. This will help avoid losing valuable data.

    Before moving on, let us first differentiate these file types:

    *FAT – also known as File Allocation Table, which is mainly used for MS-DOS and other earlier versions of Windows

    *NTFS – also known as New Technology File System, which is a newer version of a file system that is more powerful than the FAT system and uses security enhancements and features.

    To successfully convert your files, you have to:

    • Realign the partition before starting the conversion process. Preferably, you can move the data to an area of about 4k boundary. You can try looking for a shareware program that has partition management and disk imaging capabilities.

    To understand how you can convert your FAT32 volume to an NFTS file system, you must consider certain limitations:

    • You cannot convert UDF and CDFS to NFTS since these are only used for optical media.
    • You must use the FAT12 format for floppy disks.
    • If you convert a FAT32 to an NFTS file system, it might run poorly on Windows 2000. However, this will not happen if you have a clear partition of NFTS. It is recommended to use a convert command when converting the FAT volume to NFTS to make sure all your files are intact.
    • The conversion is a one-way process. You cannot convert a file back to FAT volume once you have converted it to NFTS. If you want, you can reformat it to a FAT system. Doing this will remove all existing data, which includes programs and personal files.
    • When converting, using the convert command, you need to have available space on your drive. If there is not enough space, the convert command will not push through with the conversion process.

    Here is the basic step to the conversion process:

    1. Click to Start, All Programs, Accessories, then Command Prompt. Type in ‘/fs:ntfs’ at the command prompt.
    2. You will be prompted to restart your system since the conversion process cannot begin while the program is running. As soon as prompted, choose YES.
    3. Indicate the volume label of the drive you are about to convert, and choose ENTER. Your type of file system is FAT.
    4. As soon as the conversion to NTFS is done, a message will be indicated on-screen saying: “Conversion complete.” Your file conversion is successful.

    SAN

    A Storage Area Network (SAN) is a computer storage network composed of storage devices like disk arrays, optical jukeboxes, and tape libraries linked to a server and other devices.

    A SAN is a collection of numerous fabric switches hooked up to a network. The most popular forms of SAN use Fibre Channel Fabric Protocol with Fibre Channel switches.

    Disk array controllers and servers connect to the SAN. The servers in the network share the storage in the disk array controllers’ hard disks.

    Every storage device in a SAN is accessible to all LAN (Local Area Network) or WAN (Wireless Area Network) servers. Any additional storage device added to a SAN will also be available for access from any server in the greater network. Here, the server is merely a pathway between the stored data and the end user.

    Problems arising from the complex management of Network Attached Storage (NAS) devices brought about the invention of SANs.

    NAS employs file-based protocol. In this network, storage systems are remote and the computers will need only a part of an abstract file as opposed to an entire disk block.

    NAS device capacity was difficult to control. In addition, network traffic and delays were common to the Operating Systems of NAS network stacks. These problems are almost nonexistent in SANs.

    SANs support different network processes such as disk mirroring, file backup and restoration, data archival and retrieval, data migration between storage devices, and data sharing among network servers.

    SANs are also capable of incorporating sub-networks and Network Attached Storage (NAS) systems. Hence, data storage technology forecasts an escalation in the use of SAN over the coming years.

    HBA

    A Host Bus Adapter (HBA) is an interface card linking a host to a Storage Area Network (SAN). More accurately known as a Host I/O Controller, an HBA is an integrated circuit adapter and/or circuit board that provides physical connectivity and input/output (I/O) processing between a storage device and a server.

    The HBA enhances server performance by relieving the host microprocessor of retrieval tasks and data storage. An HBA and its related disk subsystems are also known as a disk channel.

    The HBA connects a computer’s host system to other network and storage devices. The HBA is also called a host controller or host adapter. The latter terms mainly denote devices that link SCSI, Fibre Channel, and eSATA devices. It is also used to refer to devices connecting to IDE, Ethernet, FireWire, Universal Serial Bus (USB), and other systems.

    Recent technological developments such as iSCSI have resulted in Ethernet HBAs. Ethernet HBAs differ from Ethernet NICs because the latter use hardware iSCSI- dedicated TCP Offload Engines.

    The Small Computer System Interface (SCSI) is a host adapter connecting a computer to a peripheral device like an SCSI bus. This HBA bridges the gap between the SCI bus and the computer host’s internal bus.

    The Fibre Channel (FC) is a technology used for storage networking. The HBA often refers to the FC interface card. Major open systems, buses, and computer architectures use Fibre Channel HBAs.

    The External Serial Advanced Technology Attachment (eSATA) is a bus mainly intended for the transmission of information between mass storage devices such as optical drives and hard disk drives in a computer. It is a SATA variant used for external connectivity.

    Integrated Drive Electronics (IDE) is a hardware interface used mainly to tape drives, optical disks, and hard disks to a PC. IDE drives are also known as Advanced Technology Attachment (ATA) drives.

    Ethernet is a Local Area Network (LAN) computer networking technology.

    FireWire is a serial bus interface standard mostly used in PCs. This interface involves real-time data transfer and high-speed communications. FireWire is the Apple brand name for the IEEE 1394 interface.

    Universal Serial Bus (USB) is a standard HBA that serves as an interface between devices to a computer host. This was created to connect numerous peripherals through one standard socket. USB enhances the plug-and-play capacity by permitting hot-swapping. This allows devices to be connected and disconnected without deactivating the device or rebooting the PC.

    ATAPI

    AT Attachment Packet Interface (ATAPI) is the interface between connected CD-ROM and tape backup drives in your computer. To address hard disk drives, most personal computers today use the Integrated Drive Electronics (IDE) interface. ATAPI gives further commands needed to control a CD-ROM drive or tape backup. This allows the computer to utilize the IDE interface and its controllers to manage these devices.

    ATAPI is a portion of the Enhanced IDE (EIDE) interface also known as ATA-2. This interface arose from a series of incremental developments. ATAPI was an evolution of the AT Attachment Interface, which in turn evolved from the IDE format. This evolution resulted to various interfaces with close similarity to ATAPI (terms and definitions below), including erroneously interchanged abbreviations. The original ATA was retroactively termed PATA with the introduction of Serial ATA in 2003.

    Definition of Terms:

    • ATA or PATA – Parallel ATA is the original parallel ATA interface employed by disk drives.
    • ATAPI or PATAPI – ATAPI with PATA is the interface used by CD, DVD, or tape devices.
    • SATA – Serial ATA, a Parallel ATA serial version, is the interface utilized mostly by disk drives.
    • SATAPI – Serial ATAPI, ATAPI plus SATA, is another interface used by CD, DVD, or tape devices.

    The PATA standards limit cable lengths up to 18 inches (46 centimeters) only. This length allowance makes the interface seem to be an internal computer storage. ATA has offered the least expensive and most widespread interface for this application. As of 2007, the more prevalent Serial ATA (SATA) has displaced it in newer systems.

    RAID

    RAID is an acronym for Redundant Array of Independent Disks. It involves a set of strategies to improve system performance and increase fault tolerance. Generally, two or more drives are combined to achieve this. RAID also provides better reliability and bigger data volume sizes. This is because RAID places data across a number of disks, which the Operating System sees as just one disk.

    RAID has several levels. Some of the most common are the following:

    First is RAID 0. In this RAID level, pieces of data are broken into smaller fragments as they are being written to the disk. The fragments are written to drives within the same sector. This structure allows RAID 0 to offer a larger bandwidth. However, the drawback in using RAID 0 is that one disk failure will destroy the whole array.

    RAID 1 is another level of RAID. This level uses the process of mirroring to write data to the disks. It incorporates features for fault tolerance, which enables the entire array to remain efficient as long as one disk is functioning properly. RAID 1 is relatively more costly than the previous level because it requires more disks for data storage.

    The next level is RAID 2. To enhance its error correction features, RAID 2 utilizes Hamming Codes. RAID 2 entails the synchronization of multiple parity disks.

    RAID 3, on the other hand, uses dedicated parity disks. By using this type of disks, RAID 3 ensures that processes will continue even if the parity drive stops during operation.

    The above RAID levels can be merged together to form nested RAID levels. Experts believe that doing this can greatly improve system performance.

    Partition Software

    Partition software is a tool used to create, resize, and delete partitions. A partition refers to a certain part of the hard disk allotted to an application or an Operating System. Partition software can also move, hide, and unhide partitions.

    Varying kinds of partition software have features that differ from one another. Nevertheless, these programs have a set of common features. They all have a particular module that ensures the security of data.

    The corruption or loss of files is a major concern during the creation or modification of partitions. Because of this, partition software has included features that enable the user to back up his files. This software tool also has options for file recovery, in case unexpected data loss does take place.

    An option to save information about partitions is another feature of this type of software. These applications allow the user to create a file wherein information about his partition is stored. This is useful in an event where he wishes to apply the same partition to other computers, or if he decides to reformat his PC and apply the previous partition again.

    Apart from this, partition software also offers data compression. This function involves the compression of data within the partition and the division of the compressed data into several files. This is necessary when the user wishes to save his hard drive partitions to a DVD or CD.

    Partition software can be found in several sources. There are numerous sites in the Internet from where it could be downloaded. Similar to other applications, some of these software tools are free while others need to be purchased. Software packages containing a wide array of tools are also good sources of partition software.

    Addition Resources on Partition Software