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=systemd changes=
===systemd===


===New unit types===
== storaged replaces udisks2 ==
====scope units====


====slice units====
The `udisks2` package provides dynamic storage management functionality to legacy Fedora systems. Most prominently, desktop environments like GNOME udisks to handle removable media, such as USB thumb drives, via a dbus interface.
Slice units are used to group units that manage processes into a hierarchy to allow control of resources allocated for the slice. The default slices, listed below, are automatically populated.
+ machine.slice, for virtual machines and containers
+ system.slice, for system services
+ user.slice, for user sessions 


Scope and service units assigned to a slice are descendants of that slice's node in the control group tree. A slice's name describes its position relative to the root slice. The output below demonstrates how "user-1000.slice" is a child of "user.slice" which is in turn a child of the root slice.
Because udisks2 does not support more complex storage technologies such as LVM or iSCSI, it is being replaced in Fedora 25 by `storaged`, an enhanced fork of the udisks project.  `storaged` is a drop-in replacement for `udisks2`, and the additional functionality allows administrators to use software like `Cockpit` in Fedora Server to manage these advanced storage resources.
 
 
user.slice - User and Session Slice
  Loaded: loaded (/usr/lib/systemd/system/user.slice; static)
  Active: active since Sun 2013-09-08 01:23:40 MDT; 18h ago
    Docs: man:systemd.special(7)
  CGroup: /user.slice
          ├─user-1000.slice
          │ ├─session-21.scope
          │ │ ├─9226 sshd: pete [priv]
          │ │ ├─9229 sshd: pete@pts/4
          │ │ ├─9230 -bash
          │ │ ├─9262 sudo su -
          │ │ ├─9270 su -
          │ │ ├─9271 -bash
          │ │ └─9509 screen -R
          │ ├─session-18.scope
          │ │ ├─ 7939 sshd: pete [priv]
          │ │ ├─ 7942 sshd: pete@pts/0
          │ │ ├─ 7943 -bash
          │ │ ├─ 7982 sudo su -
          │ │ ├─ 7988 su -
          │ │ ├─ 7989 -bash
          │ │ ├─ 8206 SCREEN
          │ │ ├─ 8207 /bin/bash
          │ │ ├─ 8237 /bin/bash
          │ │ ├─ 8486 less NEWS
          │ │ ├─ 8489 /bin/bash
          │ │ └─10637 systemctl status user.slice
          <truncated>
 
===Other Systemd Changes===
====systemd-cryptsetup for TrueCrypt====
<!-- this should be tested! -->
Support for TrueCrypt volumes in Fedora is expanded by systemd-cryptsetup's support for the technology, allowing easy authentication to TrueCrypt volumes during boot.
 
===systemctl===
====Filtering by unit state====
`systemctl` now supports filtering the unit list output by load state. The --state option will accept any value or a comma-separated list values of LOAD, SUB, or ACTIVE states. For example:
  systemctl --state failed
 
===journalctl===
====Viewing the logs of a specific boot====
`journalctl -b` can be used to look for boot output of a specific boot. For example:
journalctl -b # output from current boot
journalctl -b -1 #output from previous boot
 
In addition to relative boot sequence, journalctl assigns a 128bit boot ID that can be referenced. For example,
journalctl -b  38fd9c3303574ed38e822233457f6b77 # output from a specific designated boot
 
===Referencing the journal with 'cursors'===
journalctl can reference the contents of the journal by a record identifier known as a 'cursor'. Similar to a git hash, the cursor uniquely identifies a point in the journal.
If you add --show-cursor to a journalctl query, the last line of output will contain the cursor value:
journalctl -b -u network --show-cursor --since 15:00
Sep 08 15:37:59 localhost.localdomain network[4074]: [FAILED]
Sep 08 15:37:59 localhost.localdomain systemd[1]: network.service: control process exited, code=exited status=1
Sep 08 15:37:59 localhost.localdomain systemd[1]: Failed to start LSB: Bring up/down networking.
Sep 08 15:37:59 localhost.localdomain systemd[1]: Unit network.service entered failed state.
-- cursor: s=13497722134642a2ac1544bada0c8836;i=1120d;b=8491c05dabd3444ca122e7069b5de0a9;m=db2118a46;t=4e5e7d81c7402;x=d177768ac95df831
 
The cursor can be used to identify that point in the journal in a broader query to provide context:
journalctl -c "s=13497722134642a2ac1544bada0c8836;i=1120d;b=8491c05dabd3444ca122e7069b5de0a9;m=db2118a46;t=4e5e7d81c7402;x=d177768ac95df831"
 
Scripts parsing journalctl's output can store the cursor value and use it on their next run to pick up where they left off:
journalctl --after-cursor "s=13497722134642a2ac1544bada0c8836;i=1120d;b=8491c05dabd3444ca122e7069b5de0a9;m=db2118a46;t=4e5e7d81c7402;x=d177768ac95df831"


Detailed information on the storaged project is available from the upstream site at https://storaged.org .




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<!-- There's a bit about journalctl cursor seeking, but I can't find a documented definition of 'cursor' or any usage examples. It appears to be for machine users of the journal only. -->

Latest revision as of 01:32, 20 September 2016

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storaged replaces udisks2

The udisks2 package provides dynamic storage management functionality to legacy Fedora systems. Most prominently, desktop environments like GNOME udisks to handle removable media, such as USB thumb drives, via a dbus interface.

Because udisks2 does not support more complex storage technologies such as LVM or iSCSI, it is being replaced in Fedora 25 by storaged, an enhanced fork of the udisks project. storaged is a drop-in replacement for udisks2, and the additional functionality allows administrators to use software like Cockpit in Fedora Server to manage these advanced storage resources.

Detailed information on the storaged project is available from the upstream site at https://storaged.org .