In computer security, an access-control list (ACL) is a list of permissions associated with a system resource. An ACL specifies which users or system processes are granted access to resources, as well as what operations are allowed on given resources. Each entry in a typical ACL specifies a subject and an operation. For instance,
The Linux Professional Institute (LPI) is a Canadian non-profit organisation and oriented towards certifications for Linux, BSD and open-source software-based technologies. It was founded in October 1999.
The Filesystem Hierarchy Standard (FHS) is a reference describing the conventions used for the layout of Unix-like systems. It has been made popular by its use in Linux distributions, but it is used by other Unix-like systems as well. It is maintained by the Linux Foundation. The latest version is 3.0, released on 3 June 2015.
A live CD is a complete bootable computer installation including operating system which runs directly from a CD-ROM or similar storage device into a computer's memory, rather than loading from a hard disk drive. A live CD allows users to run an operating system for any purpose without installing it or making any changes to the computer's configuration. Live CDs can run on a computer without secondary storage, such as a hard disk drive, or with a corrupted hard disk drive or file system, allowing data recovery.
A virtual file system (VFS) or virtual filesystem switch is an abstract layer on top of a more concrete file system. The purpose of a VFS is to allow client applications to access different types of concrete file systems in a uniform way. A VFS can, for example, be used to access local and network storage devices transparently without the client application noticing the difference. It can be used to bridge the differences in Windows, classic Mac OS/macOS and Unix filesystems, so that applications can access files on local file systems of those types without having to know what type of file system they are accessing.
tmpfs is a temporary file storage paradigm implemented in many Unix-like operating systems. It is intended to appear as a mounted file system, but data is stored in volatile memory instead of a persistent storage device.
Filesystem in Userspace (FUSE) is a software interface for Unix and Unix-like computer operating systems that lets non-privileged users create their own file systems without editing kernel code. This is achieved by running file system code in user space while the FUSE module provides only a bridge to the actual kernel interfaces.
Oracle Solaris Cluster is a high-availability cluster software product for Solaris, originally created by Sun Microsystems, which was acquired by Oracle Corporation in 2010. It is used to improve the availability of software services such as databases, file sharing on a network, electronic commerce websites, or other applications. Sun Cluster operates by having redundant computers or nodes where one or more computers continue to provide service if another fails. Nodes may be located in the same data center or on different continents.
OS-level virtualization is an operating system (OS) virtualization paradigm in which the kernel allows the existence of multiple isolated user space instances, including containers, zones, virtual private servers (OpenVZ), partitions, virtual environments (VEs), virtual kernels, and jails. Such instances may look like real computers from the point of view of programs running in them. A computer program running on an ordinary operating system can see all resources of that computer. Programs running inside a container can only see the container's contents and devices assigned to the container.
Red Hat, an IBM subsidiary specializing in computer software, offers different level of certification programs, most of which specialize in system administration. Certifications can be validated through Red Hat webpage, and expire after 3 years.
TestDisk is a free and open-source data recovery utility that helps users recover lost partitions or repair corrupted filesystems. TestDisk can collect detailed information about a corrupted drive, which can then be sent to a technician for further analysis. TestDisk supports DOS, Microsoft Windows, Linux, FreeBSD, NetBSD, OpenBSD, SunOS, and MacOS. TestDisk handles non-partitioned and partitioned media. In particular, it recognizes the GUID Partition Table (GPT), Apple partition map, PC/Intel BIOS partition tables, Sun Solaris slice and Xbox fixed partitioning scheme. TestDisk uses a command line user interface. TestDisk can recover deleted files with 97% accuracy.
Ubuntu Professional Certification which was introduced in May 2006, was a computer based examination about the Ubuntu operating system.
An Amazon Machine Image (AMI) is a special type of virtual appliance that is used to create a virtual machine within the Amazon Elastic Compute Cloud ("EC2"). It serves as the basic unit of deployment for services delivered using EC2.
NetBSD is a free and open-source Unix-like operating system based on the Berkeley Software Distribution (BSD). It was the first open-source BSD descendant officially released after 386BSD was forked. It continues to be actively developed and is available for many platforms, including servers, desktops, handheld devices, and embedded systems.
The Computing Technology Industry Association, more commonly known as CompTIA, is an American non-profit trade association that issues professional certifications for the information technology (IT) industry. It is considered one of the IT industry's top trade associations.
OpenZFS is an open-source implementation of the ZFS file system and volume manager initially developed by Sun Microsystems for the Solaris operating system, and is now maintained by the OpenZFS Project. Similar to the original ZFS, the implementation supports features like data compression, data deduplication, copy-on-write clones, snapshots, RAID-Z, and virtual devices that can create filesystems that span multiple disks.
