block level

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block level

Reading and writing a disk at the physical level. The disk controller in every computer and server reads and writes the disks at the block level. In storage area networks (SANs), where the disks are in cabinets external to the server, read/write access is also at the block level.

Block Level vs. File Level
An application accesses data by file name (logical), which is translated into block level (physical) for reading and writing by the operating system's file system.

Users always deal with data at the file level; however, database and network administrators may get involved at the block level, because they can stipulate where data are physically stored for performance issues.

NAS vs. SAN
Although a stand-alone unit with its own disks, a network attached storage (NAS) device has its own file system for file level access. Because a SAN uses block level access and has no file system with its associated overhead, a SAN is much faster than a NAS. See SAN, NAS and file system.

Remote Block Level Access
With IP storage, block level access can be extended via the IP protocol to remote locations. See SAN and IP storage.

Blocks Are Also Logical
Modern drives maintain their own tables of good and bad sectors and remap requests on the fly. As a result, the physical block reads and writes are translated by the drive into actual sector reads and writes, making the block access somewhat like a logical request, rather than 100% physical.


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On May 26, the PTA directed ISPs to block access to, among other websites, alibaba.com, bloomberg.com, buzzfeed.com and gsmarena.com, saying that they were hosting 'unethical' content.
PLDT: No gov't order to block access to Tinder !-- -- Rosette Adel (philstar.com) - November 23, 2018 - 11:31am MANILA, Philippines Telecommunications giant PLDT, Inc.
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In an online notice, the military also said: "We urge soldiers to refrain from visiting digital token exchanges to avoid disappointment from our decision to block access to relevant sites."
Izza said APJII members have always complied with government requests to block access to certain websites.
Eager to avoid fuel shortages, centrist President Emmanuel Macron's government deployed police at some sites before dawn to ensure by force that protesters could not block access.
embassy in Moscow, said in (http://www.reuters.com/article/us-russia-linkedin-diplomacy-idUSKBN13D0ST) a statement to Reuters: "The United States is deeply concerned by Russia's decision to block access to the website LinkedIn.
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INDIA has ordered internet service providers (ISPs) to block access to more than 850 adult websites in what the government has described as a way to protect social decency.
It is possible that if an English court was to rule that the content of this web page was illegal, internet companies in the UK could be required to block access to it.
A Turkish court has asked USbased social website, Facebook, to locally block access to pages considered blasphemous towards Prophet Muhammad and religion, or face a complete ban in the country.