Bootstrapping Flashcards
What is bootstrapping?
It is the process when a computer starts and it is composed of a few broadly defined tasks:
•
Finding, loading, and running bootstrapping code
•
Finding, loading, and running the OS kernel
•
Running startup scripts and system daemons
What is a system firmware?
It is the first program that is executed and it is stored in ROM. It knows all the devices.
How traditional pc firmware i is called?
BIOs
What assumastions legacy bios does?
It assumes that the boot device starts with a record celled MBR.The MBR includes both a first-stage boot loader (aka “bootblock”) and a primitive disk partitioning table. The amount of space available forthe boot loader is so small (less than 512 bytes) that it’s not able to do much other than load and run a second-stage boot loader.
Where grub config is stored?
Plain text under /boot/grub?
What is spontaneous process?
Once the kernel has been loaded and has completed its initialization process, it cre-
ates a complement of spontaneous” processes in user space.You can recognize them in ps listings (see page 98) by their low PIDs and by the brackets around their
names
What is the role of init?
init has multiple functions, but its overarching goal is to make sure the system runs
the right complement of services and daemons at any given time.
To serve this goal, init maintains a notion of the mode in which the system should
be operating. Some commonly defined modes:9
• Single-user mode, in which only a minimal set of filesystems is mounted,
no services are running, and a root shell is started on the console
• Multiuser mode, in which all customary filesystems are mounted and all
configured network services have been started, along with a window sys-
tem and graphical login manager for the console
• Server mode, similar to multiuser mode, but with no GUI running on
the console
What replaced inti?
systemd
What is systemd?
systemd is not a single daemon but a collection of programs, daemons, libraries,
technologies, and kernel components.
What is unit regarding systemd?
An entity that is managed by systemd .Within systemd, the behavior of each unit is defined and configured by a unit file.
In the case of a service, for example, the unit file specifies the location of the ex-
ecutable file for the daemon, tells systemd how to start and stop the service, and
identifies any other units that the service depends on.
What is systemctl?
systemctl is an all-purpose command for investigating the status of systemd and
making changes to its configuration.
How systemd manages the log management?
It provides an universal logging framework.This facility, called the journal, is managed by the journald daemon.
Without arguments, journalctl displays all log entries (oldest first):
Which are the basic mainline principles of unix access control?
Access control decisions depend on which user is attempting to perform an
operation, or in some cases, on that user’s membership in a UNIX group.
• Objects (e.g., files and processes) have owners. Owners have broad (but
not necessarily unrestricted) control over their objects.
• You own the objects you create.
• The special user account called “root” can act as the owner of any object.
• Only root can perform certain sensitive administrative operations.1
What is uid?
A specific unique number which correspond to owners and user groups
What is sudo?
Grants root access to a sudoer user without su to root.
File for config /etc/sudoers
