If you want to run Fedora 15 on a slow spinning disk, then you have to customize it a bit, to get fast boot times.
First we choose a manual disk layout and use primary partitions and format them with ext4. In my case this results in:
sda1 ext4 /boot
sda2 swap
sda3 ext4 /
After the first boot, setup of the user, etc. and 2 reboots (always reboot 2 times, before taking the measurement, because readahead needs to adapt to the changed boot process), I measure 45 seconds from the grub menu to the graphical login screen. To get the grub menu, just hold down <ALT> in the boot phase. 45 seconds is a little bit slow compared to the other distributions. systemd-analyse gives me the output: Startup finished in 5585ms (kernel) + 5509ms (initrd) + 21847ms (userspace) = 32942ms
The next step is to disable the initramfs, because the kernel can boot from an ext4 partition without it. Because I know how to rescue my system, I can set the root device directly to sda3 and tell the kernel which filesystem type to use. My /etc/grub.conf looks like this:
title Fedora (2.6.38.6-26.rc1.fc15.i686.PAE)
root (hd0,0)
kernel /vmlinuz-2.6.38.6-26.rc1.fc15.i686.PAE ro root=/dev/sda3 rootfstype=ext4 rhgb quiet
# initrd /initramfs-2.6.38.6-26.rc1.fc15.i686.PAE.img
Rebooting gives 40 seconds to the login screen. systemd-analyse prints: Startup finished in 7897ms (kernel) + 21470ms (userspace) = 29367ms
Because I don't use any LVM, RAID or encrypted devices, I can safely turn off all fedora-* services. Additionally I turn off the plymouth boot splash, because I want speed and not eye candy. To turn off these services, you have to use the /dev/null softlink mechanism, because these services cannot be disabled by "systemctl disable". A bonus with that mechanism is, that no rpm %post script turns them on automatically, without me knowing :-)
# cd /lib/systemd/system
# for i in fedora-* plymouth-*; do sudo ln -s /dev/null /etc/systemd/system/$i;done
Now the boot time is down to 37 seconds. systemd-analyse prints: Startup finished in 7894ms (kernel) + 17992ms (userspace) = 25887ms
From now on, you really have to know what you are doing and how to revert your actions. To compare Fedora 15 with e.g. Ubuntu, I will now turn off all services except sshd. The result will be a Linux system without mail, firewall, printing and selinux security.
$ for i in abrt-ccpp abrt-oops cups mdmonitor netfs nfslock pcscd portreserve rpcbind rpcgssd rpcidmapd sendmail smolt ip6tables iptables sandbox selinux; do sudo chkconfig $i off;done
To disable selinux, edit /etc/selinux/config and/or add "selinux=0" to the kernel command line. My /etc/grub.conf now looks like this:
title Fedora (2.6.38.6-26.rc1.fc15.i686.PAE)
root (hd0,0)
kernel /vmlinuz-2.6.38.6-26.rc1.fc15.i686.PAE ro root=/dev/sda3 rootfstype=ext4 selinux=0
# initrd /initramfs-2.6.38.6-26.rc1.fc15.i686.PAE.img
A reboot shows, that we are now down to a nice 26 seconds. systemd-analyse prints: Startup finished in 6157ms (kernel) + 12048ms (userspace) = 18206ms
Because I turned off selinux, I can also remove some packages :-)
# sudo yum remove $(rpm -qf --qf '%{name}\n' /etc/init.d/auditd /lib/systemd/system/{abrtd.service,mcelog.service})
I also like the idea of automounting (systemd's automount feature was an idea of mine :-) ). So I turn /boot in a "mount on demand" mountpoint. Also having /tmp as a tmpfs is one way to reduce disk activity (useful for e.g. a slow flash disk).
My resulting /etc/fstab looks like this:
/dev/sda3 / ext4 defaults 1 1
/dev/sda1 /boot ext4 noauto,comment=systemd.automount 1 2
/dev/sda2 swap swap defaults 0 0
tmpfs /tmp tmpfs defaults 0 0
A reboot gives still 26 seconds, systemd-analyse: Startup finished in 6121ms (kernel) + 12772ms (userspace) = 18894ms
To see the difference readahead makes for the system, I turn it off temporarily and reboot
# cd /lib/systemd/system
# for i in *readahead*; do systemctl disable $i;done
rm '/etc/systemd/system/default.target.wants/systemd-readahead-collect.service'
rm '/etc/systemd/system/default.target.wants/systemd-readahead-replay.service'
Without readahead it takes 32 seconds to be able to login. systemd-analyse says: Startup finished in 6125ms (kernel) + 10992ms (userspace) = 17118ms
As we can see it's real 26 versus 32 seconds. The output of systemd-analyse would be misleading, if we only relied on that!!
So, because I like 26 seconds more, I turn on readahead again :-) To check, if readahead has an updated list, do a "ls -l /.readahead" to see the timestamp and check the return status of readahead ("systemctl status systemd-readahead-collect.service"). There might be a selinux related bug, because with selinux turned on, the collector always returned with error status 1 in my testing.
# cd /lib/systemd/system
# for i in *readahead*; do systemctl enable $i;done
For the reference here is the list of services, that are started:
# LANG=C chkconfig --list|fgrep 5:on
Note: This output shows SysV services only and does not include native
systemd services. SysV configuration data might be overridden by native
systemd configuration.
cpuspeed 0:off 1:on 2:on 3:on 4:on 5:on 6:off
sshd 0:off 1:off 2:on 3:on 4:on 5:on 6:off
# systemctl
boot.automount loaded active waiting boot.automount
dev-hugepages.automount loaded active waiting Huge Pages File System Automount Point
dev-mqueue.automount loaded active waiting POSIX Message Queue File System Automount Point
proc-sys...misc.automount loaded active waiting Arbitrary Executable File Formats File System Automount Point
sys-kern...ebug.automount loaded active waiting Debug File System Automount Point
sys-kern...rity.automount loaded active waiting Security File System Automount Point
sys-devi...ock-sdb.device loaded active plugged Flash_HS-CF
sys-devi...ock-sdc.device loaded active plugged Flash_HS-COMBO
sys-devi...d-card1.device loaded active plugged SB Live! EMU10k1
sys-devi...net-em1.device loaded active plugged 82540EM Gigabit Ethernet Controller
sys-devi...da-sda1.device loaded active plugged ST380011A
sys-devi...da-sda2.device loaded active plugged ST380011A
sys-devi...da-sda3.device loaded active plugged ST380011A
sys-devi...ock-sda.device loaded active plugged ST380011A
sys-devi...ock-sr0.device loaded active plugged PIONEER_DVD-RW_DVR-105
sys-devi...d-card0.device loaded active plugged 82801EB/ER (ICH5/ICH5R) AC'97 Audio Controller
sys-devi...y-ttyS1.device loaded active plugged /sys/devices/platform/serial8250/tty/ttyS1
sys-devi...y-ttyS2.device loaded active plugged /sys/devices/platform/serial8250/tty/ttyS2
sys-devi...y-ttyS3.device loaded active plugged /sys/devices/platform/serial8250/tty/ttyS3
sys-devi...y-ttyS0.device loaded active plugged /sys/devices/pnp0/00:08/tty/ttyS0
sys-devi...ock-md0.device loaded active plugged /sys/devices/virtual/block/md0
sys-devi...ty-tty0.device loaded active plugged /sys/devices/virtual/tty/tty0
sys-devi...ty-tty1.device loaded active plugged /sys/devices/virtual/tty/tty1
sys-devi...y-tty10.device loaded active plugged /sys/devices/virtual/tty/tty10
sys-devi...y-tty11.device loaded active plugged /sys/devices/virtual/tty/tty11
sys-devi...y-tty12.device loaded active plugged /sys/devices/virtual/tty/tty12
sys-devi...ty-tty2.device loaded active plugged /sys/devices/virtual/tty/tty2
sys-devi...ty-tty3.device loaded active plugged /sys/devices/virtual/tty/tty3
sys-devi...ty-tty4.device loaded active plugged /sys/devices/virtual/tty/tty4
sys-devi...ty-tty5.device loaded active plugged /sys/devices/virtual/tty/tty5
sys-devi...ty-tty6.device loaded active plugged /sys/devices/virtual/tty/tty6
sys-devi...ty-tty7.device loaded active plugged /sys/devices/virtual/tty/tty7
sys-devi...ty-tty8.device loaded active plugged /sys/devices/virtual/tty/tty8
sys-devi...ty-tty9.device loaded active plugged /sys/devices/virtual/tty/tty9
-.mount loaded active mounted /
home-harald-.gvfs.mount loaded active mounted /home/harald/.gvfs
media.mount loaded active mounted Media Directory
sys-fs-f...nections.mount loaded active mounted /sys/fs/fuse/connections
tmp.mount loaded active mounted /tmp
systemd-...d-console.path loaded active waiting Dispatch Password Requests to Console Directory Watch
systemd-...word-wall.path loaded active waiting Forward Password Requests to Wall Directory Watch
accounts-daemon.service loaded active running Accounts Service
acpid.service loaded active running ACPI Event Daemon
atd.service loaded active running Job spooling tools
avahi-daemon.service loaded active running Avahi mDNS/DNS-SD Stack
console-...daemon.service loaded active running Console Manager
console-...-start.service loaded active exited Console System Startup Logging
cpuspeed.service loaded active exited LSB: processor frequency scaling support
crond.service loaded active running Command Scheduler
dbus.service loaded active running D-Bus System Message Bus
getty@tty2.service loaded active running Getty on tty2
getty@tty3.service loaded active running Getty on tty3
getty@tty4.service loaded active running Getty on tty4
getty@tty5.service loaded active running Getty on tty5
getty@tty6.service loaded active running Getty on tty6
hwclock-load.service loaded active exited Apply System Clock UTC Offset
irqbalance.service loaded active running irqbalance daemon
NetworkManager.service loaded active running Network Manager
prefdm.service loaded active running Display Manager
rc-local.service loaded active exited /etc/rc.local Compatibility
remount-rootfs.service loaded active exited Remount Root FS
rsyslog.service loaded active running System Logging Service
rtkit-daemon.service loaded active running RealtimeKit Scheduling Policy Service
smartd.service loaded active running Self Monitoring and Reporting Technology (SMART) Daemon
sshd.service loaded active running LSB: Start up the OpenSSH server daemon
system-s...yboard.service loaded active running System Setup Keyboard
systemd-logger.service loaded active running Stdio Syslog Bridge
systemd-...ollect.service loaded active exited Collect Read-Ahead Data
systemd-...replay.service loaded active exited Replay Read-Ahead Data
systemd-...pi-vfs.service loaded active exited Remount API VFS
systemd-sysctl.service loaded active exited Apply Kernel Variables
systemd-...-setup.service loaded failed failed Recreate Volatile Files and Directories
systemd-...ssions.service loaded active exited Permit User Sessions
systemd-...-setup.service loaded active exited Setup Virtual Console
udev-trigger.service loaded active exited udev Coldplug all Devices
udev.service loaded active running udev Kernel Device Manager
avahi-daemon.socket loaded active listening Avahi mDNS/DNS-SD Stack Activation Socket
dbus.socket loaded active running D-Bus System Message Bus Socket
syslog.socket loaded active running Syslog Socket
systemd-initctl.socket loaded active listening /dev/initctl Compatibility Named Pipe
systemd-logger.socket loaded active running Stdio Syslog Bridge Socket
systemd-shutdownd.socket loaded active listening Delayed Shutdown Socket
udev.socket loaded active listening udev Kernel Device Manager Socket
dev-sda2.swap loaded active active /dev/sda2
basic.target loaded active active Basic System
cryptsetup.target loaded active active Encrypted Volumes
getty.target loaded active active Login Prompts
graphical.target loaded active active Graphical Interface
local-fs.target loaded active active Local File Systems
multi-user.target loaded active active Multi-User
network.target loaded active active Network
sockets.target loaded active active Sockets
sound.target loaded active active Sound Card
swap.target loaded active active Swap
sysinit.target loaded active active System Initialization
syslog.target loaded active active Syslog
time-sync.target loaded active active System Time Synchronized
systemd-...ead-done.timer loaded active elapsed Stop Read-Ahead Data Collection 10s After Completed Startup
systemd-...es-clean.timer loaded active waiting Daily Cleanup of Temporary Directories
For the reference here is the dmesg output.
