What is sid in linux

What is sid in linux

Debian Unstable (also known by its codename «Sid») is not strictly a release, but rather a rolling development version of the Debian distribution containing the latest packages that have been introduced into Debian.

As with all Debian release names, Sid takes its name from a ToyStory character. In the movie, Sid is the kid next door who breaks his toys and makes nasty creatures of them.

While other release code names progress in time from being «testing» to being «stable», Sid is forever doomed to being unstable. Sid will always be the unstable branch. When the current «testing» repository becomes mature and is released, «testing» becomes the latest «stable» release. From there, a new «testing» repository will be created with the next planned code name, and packages will continue to trickle down from Sid into «testing» just as before.

Sid is where packages go after they’ve been uploaded by their maintainer, and cleared for release by the FTP master. When packages have met certain criteria, they are automatically moved from Sid to the current «testing» repository. The «Unstable» repository is updated every 6 hours.

Sid exclusively gets security updates through its package maintainers. The Debian Security Team only maintains security updates for the current «stable» release.

Installation

There are no «unstable» full CD or DVD images. Due to the fact that the packages in «unstable» change so quickly, it is more appropriate for people to download and install «unstable» using a normal Debian FTP mirror.

• Use the current «stable» installer to install a minimal stable system (recommended).
  • Change your apt sources to point to «unstable».
  • Run apt update and apt full-upgrade.
  • Change your apt sources to point to «unstable».
  • Run apt update and apt full-upgrade.
  • Download the «mini.iso» for your CPU architecture located here: https://d-i.debian.org/daily-images/ under */daily/netboot/
  • During the installation choose «Advanced options» -> «Expert install».
  • In the step «Choose a mirror of the Debian archive» choose version «sid — unstable»

  If you are already using a stable system use the method described above for upgrading to unstable changing your apt sources from «stable» (or the codename for the current stable) to «unstable».

  FAQ

  What are some best practices for testing/sid users?

  The most important thing is to keep in mind that you are participating in the development of Debian when you are tracking Testing or Unstable. This means that you should know your way around Linux, Debian, and the Debian packaging system.

  • Consider (especially when using unstable) if you need to disable or remove unattended-upgrades in order to control when package updates take place.
  • Always be careful when you perform updates and check if the actions proposed by the package managing tools are in line with your wishes and expectations. (i.e. make sure that you do not remove a plethora of packages you need by blindly accepting the proposed action)
  • Choose the right time to upgrade: when you have time to investigate any potential issue, and after saving your work and doing backups — not before some business trip!
  • Use apt upgrade instead of apt full-upgrade to avoid unwanted removal of any packages that you depend on.
  • If a package cannot be upgraded safely put it on hold using apt-mark.
  • Install the apt-listbugs and apt-listchanges packages in order to be made aware of grave bugs or important changes when you install new packages or during an upgrade.
  • Automatically create daily, weekly and monthly backups in order to ensure that corrupted data is not a problem. It’s extremely uncommon for an update to corrupt user’s data but backups also protect you from drive failures and human errors.
  • Use a Copy-On-Write (abbreviated as COW) supported filesystem like btrfs or take advantage of LVM snapshots. Take snapshots before and after an upgrade. In case, if the system is in unrecoverable position, rollback to the last snapshot from a system rescue LiveCD. A useful program for this, as well as regular system backups is timeshift
  • Consider subscribing to debian-devel-announce@lists.debian.org (very low-traffic mailing list, 1 to 10 per month) to be notified on future technical changes or possible problems.
  • Keep a good live CD/USB such as Debian Live around at all times so you can still work on the system even if it is not booting anymore.

  Does Sid have package «X»?

  You can track the status of any package by using the Debian Package Tracker.

  Is package «X» broken?

  If it doesn’t work for you, then there’s a good chance it’s broken. Your problem may either be unique to your system or experienced between several users. Because of this, Debian has a Bug Tracking System (abbreviated as BTS). Feel free to submit a bug report if you don’t see your bug already there. Please read How to report a bug using reportbug and reportbug if you are unsure how to write a good bug report.

  Can I use Sid packages on «stable»?

  Trying to do so is highly discouraged. Attempting to mix packages between Debian repositories will likely create an unusable system. For more information about best practices, check out DontBreakDebian.

  If you wish to use newer software, it is best to install packages from Backports.

  Can I use Sid packages on «testing»?

  Yes, with some care. This is referred to as a «Testing-Unstable Mix». Configuration is required to ensure a testing system stays on testing, without apt upgrading every package to the unstable version.

  First, create /etc/apt/apt.conf.d/20-tum.conf with these contents:

  APT::Default-Release "testing";

  Then, edit /etc/apt/sources.list and copy one testing line to unstable, for instance:

  deb https://deb.debian.org/debian trixie main deb https://deb.debian.org/debian unstable main

  Run apt update to refresh the cache. Use apt -t unstable install foo to install package foo from unstable rather than testing.

  • Synaptic (and possibly other gui package frontends) ignores the Default-Release setting. Set in Preferences->Distribution.
  • Make sure to remove 20-tum.conf and any unstable sources.list entry before testing is released as stable.

  Where can I get help with Sid?

  You can get help in the #debian-next channel on OFTC and on the mailing lists.

  See also

  • Unstable
    • Avoid using the unstable branch and Security support for the testing branch (from the «Securing Debian Manual»)
    • Status/Unstable — Current status of Unstable.
    • For information about packages in Sid for your architecture, see auto-builder status.
    • https://www.debian.org/releases/unstable/
    • Mailing list: debian-devel.
    • Debian Stable — The official Debian release (the one with the fewer bugs and fewer security issues).
    • Debian Testing — repository with packages from unstable, if no bugs are found within 10 days.

    Источник

    What do the identifiers PID, PPID, SID, PGID, UID, EUID mean?

    unix.stackexchange.com/questions/82724 has names for PGID and SID, if that’s what you’re looking for.

    Two possibilities: your teacher wants you to print environment variables variables or your teacher wants you to use UNIX APIs to get the values that the system put into those variables. E.g. PPID is parent’s process PID. Try echo $PPID to see it in your environment.

    1 Answer 1

    • PID — Process ID
    • PPID — Parent Process ID
    • SID — Session ID
    • PGID — Process Group ID
    • UID — User ID
    • EUID — Effective User ID

    Take a look at this SO Post and the first answer for a healthy explanation of what they’re for.

    3.270 Parent Process ID

    An attribute of a new process identifying the parent of the process. The parent process ID of a process is the process ID of its creator, for the lifetime of the creator. After the creator’s lifetime has ended, the parent process ID is the process ID of an implementation-defined system process.

    3.343 Session

    A collection of process groups established for job control purposes. Each process group is a member of a session. A process is considered to be a member of the session of which its process group is a member. A newly created process joins the session of its creator. A process can alter its session membership; see setsid(). There can be multiple process groups in the same session.

    3.296 Process Group

    A collection of processes that permits the signaling of related processes. Each process in the system is a member of a process group that is identified by a process group ID. A newly created process joins the process group of its creator.

    3.297 Process Group ID

    The unique positive integer identifier representing a process group during its lifetime.

    3.142 Effective User ID †

    An attribute of a process that is used in determining various permissions, including file access permissions; see also User ID.

    † Note that the EUID and EGID (Effect Group ID) are not used for filesystem permissions under Linux which takes filesystem’s FSUID and FSGID fields respectively instead.

    Источник

    sid — Man Page

    Storage Instantiation Daemon (SID) aims to help with Linux storage device state tracking that encompasses device layers, groups and whole stacks by monitoring progression of events. Based on monitored states and further recorded information, it is able to trigger associated actions for well-defined triggers, including activation and deactivation of devices and their layers in the stack.

    SID positions itself on top of udev, reacting to udev uevents. It is closely interlinked and cooperating with udev daemon. A specialized usid helper command is executed in udev rules to communicate with SID daemon which in turn triggers further processing.

    At its core, SID provides an infrastructure and an API for various device subsystems to create modules that handle specific device types and their abstractions. For this purpose, it organizes overall uevent processing into discrete and controlled steps and, through an API, it provides access to its own SID database for use within core parts as well as modules to store and retrieve extended information besides udev daemon’s database capabilities.

    The SID database contains both internal and general-purpose records. The internal records are accessed only through dedicated API calls which are used to track and support device dependencies, grouping, triggers and associated actions. The general-purpose records can be stored and retrieved by modules directly with a possibility to define their key components, scope of visibility and access type.

    Since SID keeps track of the overall storage device stack and grouping, it provides an insight into the stack, the device and group dependencies and it is able to notify when there are changes to certain parts of the device stack to which there needs to be an appropriate action executed either inside (using SID’s triggers and associated actions) or outside SID itself (using extended notifications that SID sends out).

    Options

    Run in verbose mode. Repeat up to 4 times to increase the level of detail of log messages.

    Display version, configuration and compilation information.

    Источник

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