Prior to RHEL 7, their distributions were built on SysV, a manager that looks much like the legacy System V (init.d, rc, runlevels...). They changed it to systemd from RHEL 7. But what is the real difference between SysV and the Unix-like System V? Why did they call it SysV, if it's the same?

I want to transfer a big file of 70MB to a virtual machine running an ancient unix(at&t 2.1 ),no cdrom driver,no ufs disk(linux give me error when i try to mount systemV ufs,with ufs 43bsd ok),no floppy(no 70MB floppy exist..) So i choose minicom+kermit On at&t side i give kermit -g file.tar On linux side i open minicom ctrl+a+s choose kermit,choose file.tar and wow...nothing happen. On at&t serial screen i see /usr/local/bin/kermit -g file.tar Return to your local Kermit and give a SERVER command. KERMIT READY TO GET...
3 EToo many retries_N"U1@ Any solution?

[Several](https://danielmiessler.com/study/the-difference-between-system-v-and-systemd/#:~:text=Here%20are%20the%20main%20differences%20between%20the%20two.,much%20more.%20SystemD%20handles%20startup%20processes%20through.service%20files.) [sources](https://fossbytes.com/systemd-vs-sys-v-vs-upstart/) [online](https://www.techtarget.com/searchdatacenter/tip/Master-Linux-service-management-on-System-V-and-systemd) discusses the difference between Linux systemd service management facility and that of System V. While there's an official website for [systemd](https://systemd.io) , I found no official definition for that of System V (I checked SVID issue 2, SVR4's User Manual, Programming Guide, and Sys Admin Guide, and Linux Filesystem Hierarchy Standard). To phrase the question to avoid it being closed as a reference request: Is System V service management facility something officially defined or just a set of conventions adopted by the user community?

I have been following official guide for installing mongodb but it wont run as a service. When i try $ whereis mongod mongod: /usr/bin/mongod /etc/mongod.conf /usr/share/man/man1/mongod.1.gz but step from the guide for starting the service $ sudo service mongod start mongod: unrecognized service

I had to restart my apache2 server in WSL yesterday, and I was surprised that I couldn't use systemctl like I do on Ubuntu; instead having to revert to sudo /etc/init.d/apache2 restart. But I thought Lennart Poettering had Microsoft ties; what's going on here?

The man page for ld makes reference to AT&T’s Link Editor Command Language, however a Google search does not offer a satisfactory explanation as to what AT&T’s Link Editor Command Language is or was, other than pointing to said man pages, whereas I expect a Wikipedia page coming up in the first five results. It seems like there is a vital piece of computing history missing here. Does anyone have some reference or historical documentation on this language? Something we can put in Wikipedia to preserve for posterity?

As a personal project I decided to start building a Linux From Scratch (System V Edition, 9.1) on a virtual machine. Everything went out correctly until the moment of entering the system through LightDM. After entering the username and password, a message appears on the screen saying that the connection was refused. I have tried to find information about the problem, but nothing is helpful. I also try using LXDM, but the same problem happened. This is the message that appears: *(Translation: Can't connect with the configuration server - Couldn't connect: Connection refused)* I can get into XFCE by running startx and startxfce4. However, when I try to enter the xfce4-session or xfsettingsd commands, the same error appears on the screen: Unable to init server: No se pudo conectar: Conexión rehusada *(Translation: Couldn't connect: Connection refused)* Please let me know in case more information is required. This is the content of the Xorg.0.log: [ 7.858] X.Org X Server 1.20.7 X Protocol Version 11, Revision 0 [ 7.858] Build Operating System: Linux 4.19.0-10-amd64 x86_64 [ 7.858] Current Operating System: Linux bluelinux 5.5.3 #4 SMP Thu Sep 24 01:13:21 UTC 2020 x86_64 [ 7.858] Kernel command line: BOOT_IMAGE=/vmlinuz-5.5.3-lfs-9.1 root=/dev/sda3 ro [ 7.858] Build Date: 24 September 2020 12:54:30AM [ 7.858] [ 7.858] Current version of pixman: 0.38.4 [ 7.858] Before reporting problems, check http://wiki.x.org to make sure that you have the latest version. [ 7.858] Markers: (--) probed, (**) from config file, (==) default setting, (++) from command line, (!!) notice, (II) informational, (WW) warning, (EE) error, (NI) not implemented, (??) unknown. [ 7.858] (==) Log file: "/var/log/Xorg.0.log", Time: Thu Sep 24 22:13:24 2020 [ 8.022] (==) Using system config directory "/usr/share/X11/xorg.conf.d" [ 8.056] (==) No Layout section. Using the first Screen section. [ 8.056] (==) No screen section available. Using defaults. [ 8.056] (**) |-->Screen "Default Screen Section" (0) [ 8.056] (**) | |-->Monitor "" [ 8.056] (==) No monitor specified for screen "Default Screen Section". Using a default monitor configuration. [ 8.056] (==) Automatically adding devices [ 8.056] (==) Automatically enabling devices [ 8.056] (==) Automatically adding GPU devices [ 8.056] (==) Max clients allowed: 256, resource mask: 0x1fffff [ 8.197] (WW) `fonts.dir' not found (or not valid) in "/usr/share/fonts/X11/misc/". [ 8.197] Entry deleted from font path. [ 8.197] (Run 'mkfontdir' on "/usr/share/fonts/X11/misc/"). [ 8.223] (WW) `fonts.dir' not found (or not valid) in "/usr/share/fonts/X11/100dpi/". [ 8.223] Entry deleted from font path. [ 8.223] (Run 'mkfontdir' on "/usr/share/fonts/X11/100dpi/"). [ 8.224] (WW) `fonts.dir' not found (or not valid) in "/usr/share/fonts/X11/75dpi/". [ 8.224] Entry deleted from font path. [ 8.224] (Run 'mkfontdir' on "/usr/share/fonts/X11/75dpi/"). [ 8.224] (==) FontPath set to: /usr/share/fonts/X11/TTF/, /usr/share/fonts/X11/OTF/, /usr/share/fonts/X11/Type1/ [ 8.224] (==) ModulePath set to "/usr/lib/xorg/modules" [ 8.224] (II) The server relies on udev to provide the list of input devices. If no devices become available, reconfigure udev or disable AutoAddDevices. [ 8.224] (II) Loader magic: 0x616cc0 [ 8.224] (II) Module ABI versions: [ 8.224] X.Org ANSI C Emulation: 0.4 [ 8.224] X.Org Video Driver: 24.1 [ 8.224] X.Org XInput driver : 24.1 [ 8.224] X.Org Server Extension : 10.0 [ 8.224] (++) using VT number 7 [ 8.224] (II) systemd-logind: logind integration requires -keeptty and -keeptty was not provided, disabling logind integration [ 8.224] (II) xfree86: Adding drm device (/dev/dri/card0) [ 8.225] (--) PCI:*(0@0:2:0) 15ad:0405:15ad:0405 rev 0, Mem @ 0xf0000000/134217728, 0xf8000000/2097152, I/O @ 0x0000d010/16, BIOS @ 0x????????/131072 [ 8.225] (WW) Open ACPI failed (/var/run/acpid.socket) (No such file or directory) [ 8.225] (II) LoadModule: "glx" [ 8.274] (II) Loading /usr/lib/xorg/modules/extensions/libglx.so [ 8.828] (II) Module glx: vendor="X.Org Foundation" [ 8.828] compiled for 1.20.7, module version = 1.0.0 [ 8.828] ABI class: X.Org Server Extension, version 10.0 [ 8.828] (==) Matched vmware as autoconfigured driver 0 [ 8.828] (==) Matched modesetting as autoconfigured driver 1 [ 8.828] (==) Matched fbdev as autoconfigured driver 2 [ 8.828] (==) Matched vesa as autoconfigured driver 3 [ 8.828] (==) Assigned the driver to the xf86ConfigLayout [ 8.828] (II) LoadModule: "vmware" [ 8.834] (II) Loading /usr/lib/xorg/modules/drivers/vmware_drv.so This is the content of lightdm.log: [+0.00s] DEBUG: Logging to /var/log/lightdm/lightdm.log [+0.00s] DEBUG: Starting Light Display Manager 1.30.0, UID=0 PID=610 [+0.00s] DEBUG: Loading configuration dirs from /usr/share/lightdm/lightdm.conf.d [+0.00s] DEBUG: Loading configuration dirs from /usr/local/share/lightdm/lightdm.conf.d [+0.00s] DEBUG: Loading configuration dirs from /etc/xdg/lightdm/lightdm.conf.d [+0.00s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf [+0.00s] DEBUG: Registered seat module local [+0.00s] DEBUG: Registered seat module xremote [+0.00s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager [+0.17s] DEBUG: _g_io_module_get_default: Found default implementation local (GLocalVfs) for ‘gio-vfs’ [+0.27s] DEBUG: Monitoring logind for seats [+0.27s] DEBUG: New seat added from logind: seat0 [+0.27s] DEBUG: Seat seat0: Loading properties from config section Seat:* [+0.27s] DEBUG: Seat seat0: Starting [+0.27s] DEBUG: Seat seat0: Creating greeter session [+0.29s] DEBUG: Seat seat0: Creating display server of type x [+0.30s] DEBUG: posix_spawn avoided (fd close requested) [+0.30s] DEBUG: Could not run plymouth --ping: Failed to execute child process “plymouth” (No such file or directory) [+0.30s] DEBUG: Using VT 7 [+0.30s] DEBUG: Seat seat0: Starting local X display on VT 7 [+0.30s] DEBUG: XServer 0: Logging to /var/log/lightdm/x-0.log [+0.30s] DEBUG: XServer 0: Writing X server authority to /var/run/lightdm/root/:0 [+0.30s] DEBUG: XServer 0: Launching X Server [+0.30s] DEBUG: Launching process 626: /usr/bin/X :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch [+0.30s] DEBUG: XServer 0: Waiting for ready signal from X server :0 [+0.30s] DEBUG: Acquired bus name org.freedesktop.DisplayManager [+0.30s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat0 [+3.06s] DEBUG: Loading users from org.freedesktop.Accounts [+3.08s] DEBUG: User /org/freedesktop/Accounts/User1000 added

Linux supports two kinds of message queues: POSIX (i.e., those created by mq_open ), and System V (i.e., those created by msgget ). For POSIX message queues, mq_overview(7) documents that you can enumerate them via the mqueue virtual filesystem, usually mounted at /dev/mqueue. However, System V message queues don't show up there. How can I enumerate them?

As the title says I want to make a ubuntu package that people could download with apt and I would like to set up the package with a System V script so that people can start and stop the service (like mysql). I've already read this article https://packaging.ubuntu.com/html/packaging-new-software.html but it too basic and didn't fully understand it, How do I tell the packager in wich folders goes what? I'm a little lost and I would appreciate any help. Thanks. This guide is really helpful https://blog.serverdensity.com/how-to-create-a-debian-deb-package/ Also here is the proper documentation that the guide is using https://wiki.debian.org/Packaging/Intro?action=show&redirect=IntroDebianPackaging

System V (by AT&T) is the ancestral Unix, and I have used it. But I have never read or heard anything about systems I-IV, other than they existed once upon a time in the dim past. How effective were they, and were they widespread? Is it possible to get one's hand on the code and/or install it? Does anyone here have any experience with these earlier systems?

In my previous post , about the Linux kernel, - the structure task_struct represents threads i.e. light weight processes, but not processes. - processes are not represented by any structure, but by groups of threads sharing the same thread group id. I was wondering how differently or similarly a typical Unix kernel (System V, FreeBSD, ...) implements processes and threads at a high level? Thanks.

In manpage of ps tid TID the unique number representing a dispatchable entity (alias lwp, spid). This value may also appear as: a process ID (pid); a process group ID (pgrp); a session ID for the session leader (sid); a thread group ID for the thread group leader (tgid); and a tty process group ID for the process group leader (tpgid). tgid TGID a number representing the thread group to which a task belongs (alias pid). It is the process ID of the thread group leader. In Ubuntu, tid and tgid seem always the same as pid, for both user processes, and kernel threads (I run ps -o pid,tid,tgid,cmd) Is it true in Linux, and why? Is it true in other Unix such as System V or BSD? Thanks.

I would like to execute this shell script at reboot and shut down: #!/bin/sh touch /test Its permissions are -rwxr-xr-x 1 root root 22 Feb 24 09:34 /etc/init.d/te1 And it has this links /etc/rc0.d/K01te1 -> ../init.d/te1 /etc/rc6.d/K01te1 -> ../init.d/te1 It is working at start up if I have a this link /etc/rc5.d/S01te1 -> ../init.d/te1 But I need it running at shut down. How can I do this on Debian 8 and 9 testing? The [suggestion](https://unix.stackexchange.com/a/276808/159562) touch /var/lock/subsys/te1 didn't work.

I have a bash script that is written in a debian-based distribution (System-V) and I want to run it under CentOS 7. There is a part of the script that runs a command as a daemon like this: start-stop-daemon --start --pidfile $PIDFILE \ --chdir "$DIR" --startas $PROGRAM --name foo --chuid "$USER" -- $ARGS And stops the daemon like this: start-stop-daemon --stop --quiet --pidfile $PID \ --user "$USER" --name foo --retry=TERM/30/KILL/5 My question is how do something equivalent in CentOS 7? Is the daemon function in /etc/init.d/functions an alternative?

Unix Internal by Vahalia have figures showing the relations between processes, kernel threads, lightweight processes, and user threads. This book gives most attention to SVR4.2, and it also explores 4.4BSD, Solaris 2.x, Mach, and Digital UNIX in detail. Note that I am not asking about Linux. 1. For each process, are there always one or more lightweight processes underlying the process? Figure 3.4 seems to say yes. Why does Figure 3.5(a) show processes directly on top of CPUs, without lightweight processes in between? 2. For each lightweight process, is there always exactly one kernel thread underlying the lightweight process? Figure 3.4 seems to say yes. Why does Figure 3.5(b) show lightweight processes directly on top of processes, without any kernel thread in between? 3. Are kernel threads the only entities able to be scheduled? 4. Are lightweight processes scheduled only indirectly via scheduling the underlying kernel threads? 5. Are processes scheduled only indirectly via scheduling the underlying lightweight processes? ---------- **Update:** I asked a similar question for Linux https://unix.stackexchange.com/questions/472300/is-a-light-weight-process-attached-to-a-kernel-thread-in-linux I guessed it might be because the book Operating System Concepts introduces the concepts implicitly using Unix, and Unix and Linux might differ, so I read about Unix kernel. I appreciate the current reply, but I am hoping to reopen the post so that I can accept other replies.

Is it possible to make completion with Tab like in bash? Currently I use Esc twice, can this be changed to a tab?

I'm trying to have a System V service relaunched on exit. ***EDIT:*** Should have precised that I'm using busybox init system instead of classic systemV I found that It could be done using /etc/inittab with the keyword respawn as action (man inittab ). > respawn > The process will be restarted whenever it terminates (e.g. getty). This seems to be the right action to set, however with respawn the service will be launched at boot. I would like to have this service restarted but only after it has been launched from command line. **Is this possible to configure the service to respawn but not to be launched at boot ?**

I know that there are (at least) two types of message queues: System V message queues and POSIX message queue. To my surprise, the man page also says that the **msgget** system call for System V message queues, for example, CONFORMS TO > POSIX.1-2001, POSIX.1-2008, SVr4. Since System V message queques conformed to POSIX, why did the POSIX organization bother to invent so-called POSIX message queues that were different from System V message queues?

I'm trying to learn about rsyslog. On one of my linux boxes, I think that rsyslog has been configured to run through systemd based on this output: >systemctl status rsyslog rsyslog.service - System Logging Service Loaded: loaded (/usr/lib/systemd/system/rsyslog.service; enabled) Active: active (running) since Tue 2017-01-10 11:28:07 PST; 3 months 19 days ago Main PID: 954 (rsyslogd) CGroup: /system.slice/rsyslog.service L954 /sbin/rsyslogd -n >ps ax | grep syslog 954 ? Ssl 6:22 /sbin/rsyslogd -n On the other linux box, though, systemv (systemctl is not present) seems unaware that rsyslogd is running: [root@box ~]# service --status-all | grep -i syslog 2>&1 [root@box ~]# ps ax | grep -i syslog 7866 ? Sl 1:49 /sbin/rsyslogd -n -c5 -i /var/run/syslogd.pid Why this disparity? On the second box, is the fact that rsyslogd is running but not "found" by service evidence that it was spawned "manually" from the command-line and not configured through one of service's init.d scripts? (Sorry if my terminology is primitive). What I actually wanted to achieve was: on the second box, I wanted to restart rsyslog, and I expected to do so by running something like service rsyslog restart. But not finding rsyslog when I ran service --status-all led me down this detour. Box 1 configuration: >uname -a Linux box1 3.11.10-301.fc20.x86_64 #1 SMP Thu Dec 5 14:01:17 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux >lsb_release -a LSB Version: :core-4.1-amd64:core-4.1-noarch:cxx-4.1-amd64:cxx-4.1-noarch:desktop-4.1-amd64:desktop-4.1-noarch:languages-4.1-amd64:languages-4.1-noarch:printing-4.1-amd64:printing-4.1-noarch Distributor ID: Fedora Description: Fedora release 20 (Heisenbug) Release: 20 Codename: Heisenbug Box 2 configuration: Linux box2 2.6.37+ #2 Tue Apr 18 03:07:09 PDT 2017 armv7l GNU/Linux

In 1980's, two most prevalent operating systems came out, 1) *System V* created by AT&T 2) *BSD* created at UOC, Berkeley Some of the *BSD* variants are *OpenBSD, FreeBSD, MAC OS X* Some of the *System V* variants are AIX/HP-UX/Solaris ------------------------------------------ *Linux* is created in 1991, which is made of, *GNU tools(user space) + Linux kernel(kernel space)* ------------------------------- Comparing *UNIX kernel vs GNU hurd vs Linux kernel*, **primary**/**relevant** difference to be known to UNIX/Linux kernel user, is in **kernel integration(build) policy** approach, **In UNIX**, core kernel and service layers(like MemoryMgmt/ProcessMgmt/IPC/..) are statically compiled and linked to create a kernel executable. A single static binary file. **In GNU Hurd**, core kernel only is built into a static executable and services are built as dynamic modules. At boot up time core kernel gets loaded and stay resident in memory. Core kernel will dynamically load a service layer when it is required. Services will be unloaded when they are not required. Kernel with loadable modules. Adv/Disadv: - A single static binary file has less response time. - Kernel with loadable modules has more response time - A single static binary file takes more memory since the foot print carries complete static image with all services - Kernel with loadable modules take less memory **Linux** kernel integration(build) policy called “Modular kernel”, which is a mixture of above two policies. Hope you got the reason to mention *GNU Hurd*. ------------------------------ Mechanics of Linux/UNIX kernel, **1) working of kernel with its services** **2) providing interface to user(shell & system calls)**, were always same, as shown below, -------------------------------------------------- -------------------------------------- So, for Linux/UNIX kernel user, 1) **It is more important** to understand the difference in the aspect of **kernel integration(build) policy** approach. 2) If mechanics of UNIX vs Linux kernel, are same, then, one can further think about **less important** aspect that talks on **different implementation** of service layers(Memory_mgmt_policy/drivers/FileSy stems/.....) using C. why less important? Because, this is an abstraction to Linux/UNIX kernel user and implementation always varies(never same) in each OS and also varies in time. ----------------------------------------------- My question: To understand the difference,Unix vs Linux kernel, Do you agree with the two reasons, mentioned(above)? If no, please correct me.