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Fstab
fstab (after ''file systems table'') is a system file commonly found in the directory /etc on Unix and Unix-like computer systems. In Linux, it is part of the util-linux package. The fstab file typically lists all available disk partitions and other types of file systems and data sources that may not necessarily be disk-based, and indicates how they are to be initialized or otherwise integrated into the larger file system structure. The fstab file is read by the mount command, which happens automatically at boot time to determine the overall file system structure, and thereafter when a user executes the mount command to modify that structure. It is the duty of the system administrator to properly create and maintain the fstab file. While fstab is used for basic system configuration, for other uses, it has been superseded by automatic mounting mechanisms. The file has other names on some versions of Unix; for example, it is found at /etc/vfstab on Solaris systems. Modern use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount (Unix)
In computing, mount is a command in various operating systems. Before a user can access a file on a Unix-like machine, the file system on the device which contains the file needs to be mounted with the mount command. Frequently mount is used for SD card, USB storage, DVD and other removable storage devices. The command is also available in the EFI shell. Overview The mount command instructs the operating system that a file system is ready to use, and associates it with a particular point in the overall file system hierarchy (its ''mount point'') and sets options relating to its access. Mounting makes file systems, files, directories, devices and special files available for use and available to the user. Its counterpart umount instructs the operating system that the file system should be disassociated from its mount point, making it no longer accessible and may be removed from the computer. It is important to umount a device before removing it since changes to files may have onl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount (Unix)
In computing, mount is a command in various operating systems. Before a user can access a file on a Unix-like machine, the file system on the device which contains the file needs to be mounted with the mount command. Frequently mount is used for SD card, USB storage, DVD and other removable storage devices. The command is also available in the EFI shell. Overview The mount command instructs the operating system that a file system is ready to use, and associates it with a particular point in the overall file system hierarchy (its ''mount point'') and sets options relating to its access. Mounting makes file systems, files, directories, devices and special files available for use and available to the user. Its counterpart umount instructs the operating system that the file system should be disassociated from its mount point, making it no longer accessible and may be removed from the computer. It is important to umount a device before removing it since changes to files may have onl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pmount
In computing, mount is a command in various operating systems. Before a user can access a file on a Unix-like machine, the file system on the device which contains the file needs to be mounted with the mount command. Frequently mount is used for SD card, USB storage, DVD and other removable storage devices. The command is also available in the EFI shell. Overview The mount command instructs the operating system that a file system is ready to use, and associates it with a particular point in the overall file system hierarchy (its ''mount point'') and sets options relating to its access. Mounting makes file systems, files, directories, devices and special files available for use and available to the user. Its counterpart umount instructs the operating system that the file system should be disassociated from its mount point, making it no longer accessible and may be removed from the computer. It is important to umount a device before removing it since changes to files may have onl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount (computing)
Mounting is a process by which a computer's operating system makes files and directories on a storage device (such as hard drive, CD-ROM, or network share) available for users to access via the computer's file system. In general, the process of mounting comprises the operating system acquiring access to the storage medium; recognizing, reading, and processing file system structure and metadata on it before registering them to the virtual file system (VFS) component. The location in the VFS to which the newly mounted medium was registered is called a mount point; when the mounting process is completed, the user can access files and directories on the medium from there. An opposite process of mounting is called unmounting, in which the operating system cuts off all user access to files and directories on the mount point, writes the remaining queue of user data to the storage device, refreshes file system metadata, then relinquishes access to the device, making the storage devic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 large body of data with no way to tell where one piece of data stopped and the next began, or where any piece of data was located when it was time to retrieve it. By separating the data into pieces and giving each piece a name, the data are easily isolated and identified. Taking its name from the way a paper-based data management system is named, each group of data is called a " file". The structure and logic rules used to manage the groups of data and their names is called a "file system." There are many kinds of file systems, each with unique structure and logic, properties of speed, flexibility, security, size and more. Some file systems have been designed to be used for specific applications. For example, the ISO 9660 file system is desig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stat (Unix)
is a Unix system call that returns file attributes about an inode. The semantics of vary between operating systems. As an example, Unix command uses this system call to retrieve information on files that includes: * atime: time of last access () * mtime: time of last modification () * ctime: time of last status change () stat appeared in Version 1 Unix. It is among the few original Unix system calls to change, with Version 4's addition of group permissions and larger file size. stat() functions The C POSIX library header , found on POSIX and other Unix-like operating systems, declares the stat() functions, as well as related functions called fstat() and lstat(). The functions take a struct stat buffer argument, which is used to return the file attributes. On success, the functions return zero, and on error, −1 is returned and errno is set appropriately. The stat() and lstat() functions take a filename argument. If the file is a symbolic link, stat() returns at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ext3
ext3, or third extended filesystem, is a journaled file system that is commonly used by the Linux kernel. It used to be the default file system for many popular Linux distributions. Stephen Tweedie first revealed that he was working on extending ext2 in ''Journaling the Linux ext2fs Filesystem'' in a 1998 paper, and later in a February 1999 kernel mailing list posting. The filesystem was merged with the mainline Linux kernel in November 2001 from 2.4.15 onward. Its main advantage over ext2 is journaling, which improves reliability and eliminates the need to check the file system after an unclean shutdown. Its successor is ext4. Advantages The performance (speed) of ext3 is less attractive than competing Linux filesystems, such as ext4, JFS, ReiserFS, and XFS, but ext3 has a significant advantage in that it allows in-place upgrades from ext2 without having to back up and restore data. Benchmarks suggest that ext3 also uses less CPU power than ReiserFS and XFS. It is als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Automounter
An automounter is any program or software facility which automatically mounts filesystems in response to access operations by user programs. An automounter system utility (daemon under Unix), when notified of file and directory access attempts under selectively monitored subdirectory trees, dynamically and transparently makes local or remote devices accessible. The automounter has the purpose of conserving local system resources and of reducing the coupling between systems which share filesystems with a number of servers. For example, a large to mid-sized organization might have hundreds of file servers and thousands of workstations or other nodes accessing files from any number of those servers at any time. Usually, only a relatively small number of remote filesystems (''exports'') will be active on any given node at any given time. Deferring the mounting of such a filesystem until a process actually needs to access it reduces the need to track such mounts, increasing reliabi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
/etc
In Unix and operating systems inspired by it, the file system is considered a central component of the operating system. It was also one of the first parts of the system to be designed and implemented by Ken Thompson in the first experimental version of Unix, dated 1969. As in other operating systems, the filesystem provides information storage and retrieval, and one of several forms of interprocess communication, in that the many small programs that traditionally form a Unix system can store information in files so that other programs can read them, although pipes complemented it in this role starting with the Third Edition. Also, the filesystem provides access to other resources through so-called ''device files'' that are entry points to terminals, printers, and mice. The rest of this article uses ''Unix'' as a generic name to refer to both the original Unix operating system and its many workalikes. Principles The filesystem appears as one rooted tree of directories. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Access-control List
In computer security, an access-control list (ACL) is a list of permissions associated with a system resource (object). An ACL specifies which users or system processes are granted access to objects, as well as what operations are allowed on given objects. Each entry in a typical ACL specifies a subject and an operation. For instance, if a file object has an ACL that contains , this would give Alice permission to read and write the file and give Bob permission only to read it. Implementations Many kinds of operating systems implement ACLs or have a historical implementation; the first implementation of ACLs was in the filesystem of Multics in 1965. Filesystem ACLs A filesystem ACL is a data structure (usually a table) containing entries that specify individual user or group rights to specific system objects such as programs, processes, or files. These entries are known as access-control entries (ACEs) in the Microsoft Windows NT, OpenVMS, and Unix-like operating systems such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Setgid
The Unix access rights flags setuid and setgid (short for ''set user identity'' and ''set group identity'') allow users to run an executable with the file system permissions of the executable's owner or group respectively and to change behaviour in directories. They are often used to allow users on a computer system to run programs with temporarily elevated privileges in order to perform a specific task. While the assumed user id or group id privileges provided are not always elevated, at a minimum they are specific. The flags setuid and setgid are needed for tasks that require different privileges than what the user is normally granted, such as the ability to alter system files or databases to change their login password. Some of the tasks that require additional privileges may not immediately be obvious, though, such as the ping command, which must send and listen for control packets on a network interface. File modes The setuid and setgid bits are normally represented as t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Setuid
The Unix access rights flags setuid and setgid (short for ''set user identity'' and ''set group identity'') allow users to run an executable with the file system permissions of the executable's owner or group respectively and to change behaviour in directories. They are often used to allow users on a computer system to run programs with temporarily elevated privileges in order to perform a specific task. While the assumed user id or group id privileges provided are not always elevated, at a minimum they are specific. The flags setuid and setgid are needed for tasks that require different privileges than what the user is normally granted, such as the ability to alter system files or databases to change their login password. Some of the tasks that require additional privileges may not immediately be obvious, though, such as the ping command, which must send and listen for control packets on a network interface. File modes The setuid and setgid bits are normally represented as t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
