faster boot by Physical Block Reallocation with e4rat

alef · 2011-04-13 12:16:46

Hi,

I wanted to share this optimization which looks interesting:

howto: http://lifehacker.com/#!5790311/e4rat-c … e-commands

tool website: http://e4rat.sourceforge.net/

enjoy it

P.S. : I have not tired it myself yet, but certainly will do as soon as I am in front of my netbook...

bobrossw · 2011-04-13 13:26:43

thanks for the tip, will try it out soon!

jackbang · 2011-04-14 05:51:52

Looks good, but doesn't "preload" do this already?

bobrossw · 2011-04-14 20:33:10

So I went ahead and got it set up, and boot does feel a bit quicker, especially after I get into openbox, all my initial apps open pretty quick, including chrome. No this does not do the same thing as preload (at least based on its description) and does do some of the same things as 'readahead-fedora'.

It does one extra thing which is cool, it logs what programs are launched during boot and then defrags your disk (only on ext4) to make all of those files very close together, phyiscally. That lets your disk spin less, making the read/write times of boot faster. This extends two minutes (by default) after grub. So it can include things like the first two or three programs you usually run.

After that you can set it up as a preloader (like readahead) and it'll make the boot process even faster. I did this and at first didn't notice much improvement...then I realized I had readahead installed, so I was preloading twice. I got rid of this and now I notice a big difference.

tranche · 2011-04-17 03:13:42

Tried this on a minimal Debian install. Boot time went from ~38 to ~27 seconds.

System was an Asus 1015 PEM with 2GB.

Environment for both boots included insserv, BIOS boot-booster, 1-second Grub delay, laptop-mode-tools, sshd, wicd, cpufrequtils. After autologin X, and openbox were started with xinit. Tint2, wicd-client, volumeicon, and a Sakura terminal were started automatically in autostart.sh.

Disk format pre-e4rat was ext2 noatime. E4rat requires ext4, so I reformatted as ext4 noatime data=writeback.

Times given are from power-on to cpu idle with the Sakura terminal accepting characters. I then started Chromium immediately after booting so that its disks blocks would be reallocated along with the actual boot files. Without e4rat Chromium's first-time startup was about 3 seconds. After e4rat it started in less than 1/2 second.

Installation and configuration were easy, following the directions in the README. I used a precompiled deb package (v0.2.1) from http://e4rat.sourceforge.net

Reading e4rat's detailed boot log was a sobering experience (> 2500 files read during boot). Hundreds of these were timezone files that don't need to be read at all, so there are opportunities for improvement.

It's a useful piece of code.

Ranko Kohime · 2011-04-19 18:35:45

tranche wrote:

Reading e4rat's detailed boot log was a sobering experience (> 2500 files read during boot). Hundreds of these were timezone files that don't need to be read at all, so there are opportunities for improvement.

Is it safe to assume that e4rat can be run in manual mode for this specific purpose? (running SSD here, so no reason to defrag)

tranche · 2011-04-19 19:34:10

@alef - Yes, you could use it this way, and it's quite informative.

Just install the whole package but use only the boot logger, which is the first of the three components that you would use in a regular hard disk install. You set it up by adding an "init=" to the boot line in grub.cfg. All it will do at that point is log the files opened during boot to a disk file. Once you've gotten everything you can get out of it, you can remove the init.

Incidentally it was Chromium that was opening those hundreds time zone files. smile

jmbarnes · 2011-04-20 16:24:59

Just applied e4rat (using info on https://wiki.archlinux.org/index.php/E4rat ) and must say it feels very fast. The slowest thing in the boot process is me entering my password to decrypt /home. Once past that it flies right into my desktop (automatically login.) Certainly worth it if you reboot very often.

chaanakya · 2011-04-21 15:28:37

Just wondering...I followed the advice in the lifehacker article to the t, and it works, but I lost my splash...I'm trying to figure out why...my GRUB_CMDLINE_LINUX_DEFAULT is "init=/sbin/e4rat-preload quiet splash"

Thanks in advance!

- Chaanakya

wobbe98 · 2011-04-21 20:08:05

I've also done the e4rat thing and it shaved off 10 second of my boot time. That's 20% in my case.
I timed it three times before and after to make sure the measurement was correct.
But it also screwed up my boot splash. (plymouth)

chaanakya · 2011-04-21 20:13:30

Apparently plymouth has a problem with any init= parameter?? :'(

tranche · 2011-04-21 20:55:10

Was the splash parameter propagated into /boot/grub/grub.cfg?

I'm sure you did this already, but did you run update-grub again?

chaanakya · 2011-04-21 23:39:25

Yes it was, and yeah, I did...

Last edited by chaanakya (2011-04-21 23:39:49)

grooveharder · 2011-04-29 13:03:44

Great tip! Amazingly fast boot.

Add "plymouth:force-splash" (no quotes) to the kernel command line to keep plymouth running (found at http://wiki.mandriva.com/en/Development … timisation)

Now it boots fast and still looks pretty wink

Last edited by grooveharder (2011-04-29 13:04:33)

chaanakya · 2011-05-01 13:18:55

Thank you so much grooveharder!!! big_smile

macondo123 · 2011-05-01 22:26:29

Hi, should i uninstall 'preload'?

macondo123 · 2011-05-01 22:43:21

Never mind, i understood now smile

hardran3 · 2011-05-02 01:07:19

A great tip, thank you! Cut off 1/3 of my boot time.

lewispm · 2011-08-23 19:25:22

I'm having a problem with this guide.

Step one: Collect - worked fine.
Step two: Reallocate - adding single to the end of my kernel line still loads openbox as usual, not a non-x environment, which I assumed they meant.

The next command:

sudo e4rat-realloc /var/lib/e4rat/startup.log

throws a bunch of errors when I execute it inside Terminator. Basically, its "Operation not supported" after each line of the startup.log file.

During the bootup with single in my kernel line I have the option to debug as root. I have tried saying 'yes' to this and running the command (sans 'sudo') but it doesn't work. It just displays an 'e' on the next line and then my computer overheats because the root environment doesn't load the cpufreq I need to cool this heatbox down.

Any idea what I'm doing wrong?

hhh · 2011-08-23 20:02:05

@lewispm, what worked for me was not using the Lifehacker instructions, but the ones included in the source's ReadMe, which are echoed here...
https://wiki.archlinux.org/index.php/E4 … it_to_work

Also, I ran sudo update-grub each time I edited grub.

-edit- re: the Arch Wiki article, I didn't edit /boot/grub/grub.cfg as it's not recommended, I edited /etc/default/grub and ran update-grub.

Last edited by hhh (2011-08-23 20:05:57)

lewispm · 2011-08-23 20:12:20

hhh wrote:

Also, I ran sudo update-grub each time I edited grub.
-edit- re: the Arch Wiki article, I didn't edit /boot/grub/grub.cfg as it's not recommended, I edited /etc/default/grub and ran update-grub.

So then I should be looking for it to boot to just a command line, right?

hhh · 2011-08-24 01:08:09

No, normal boot after it's all set up.

lewispm · 2011-08-24 01:49:15

The archlinux link helped me get to runlevel 1, thanks.

But I'm still getting all the same errors when I run the e4rat-realloc command. I get a bunch of 'operation not permitted' and at the end it says that most of the files are un-writeable.

xaos52 · 2011-08-24 08:43:05

No need to reboot to get to runlevel 1:

1. Ctrl+Alt+F1 to go to virtual console 1
2. enter your user name and password
3. sudo init 1
4. Enter your user password if prompted
5. If your root account is locked, which is the default in crunchbang, you should get the # prompt
6. then you can run e4rat-realloc /var/lib/e4rat/startup.log
7 to return to runlevel 2, just type 'init 2'

If you still have problems: cat /var/lib/e4rat/startup.log
This should give you a list of filenames. If it doesnt, sth went wrong in the collect phase, try that again

You know e4rat only works for ext4 partitios, do you?

hth

lewispm · 2011-08-27 21:08:11

xaos52 wrote:

If you still have problems: cat /var/lib/e4rat/startup.log
This should give you a list of filenames. If it doesnt, sth went wrong in the collect phase, try that again

I do get a list of filenames.

xaos52 wrote:

You know e4rat only works for ext4 partitios, do you?
hth

yes, both / and /home are ext4

CrunchBang Linux

SEARCH

#1 2011-04-13 12:16:46

faster boot by Physical Block Reallocation with e4rat

#2 2011-04-13 13:26:43

Re: faster boot by Physical Block Reallocation with e4rat

#3 2011-04-14 05:51:52

Re: faster boot by Physical Block Reallocation with e4rat

#4 2011-04-14 20:33:10

Re: faster boot by Physical Block Reallocation with e4rat

#5 2011-04-17 03:13:42

Re: faster boot by Physical Block Reallocation with e4rat

#6 2011-04-19 18:35:45

Re: faster boot by Physical Block Reallocation with e4rat

#7 2011-04-19 19:34:10

Re: faster boot by Physical Block Reallocation with e4rat

#8 2011-04-20 16:24:59

Re: faster boot by Physical Block Reallocation with e4rat

#9 2011-04-21 15:28:37

Re: faster boot by Physical Block Reallocation with e4rat

#10 2011-04-21 20:08:05

Re: faster boot by Physical Block Reallocation with e4rat

#11 2011-04-21 20:13:30

Re: faster boot by Physical Block Reallocation with e4rat

#12 2011-04-21 20:55:10

Re: faster boot by Physical Block Reallocation with e4rat

#13 2011-04-21 23:39:25

Re: faster boot by Physical Block Reallocation with e4rat

#14 2011-04-29 13:03:44

Re: faster boot by Physical Block Reallocation with e4rat

#15 2011-05-01 13:18:55

Re: faster boot by Physical Block Reallocation with e4rat

#16 2011-05-01 22:26:29

Re: faster boot by Physical Block Reallocation with e4rat

#17 2011-05-01 22:43:21

Re: faster boot by Physical Block Reallocation with e4rat

#18 2011-05-02 01:07:19

Re: faster boot by Physical Block Reallocation with e4rat

#19 2011-08-23 19:25:22

Re: faster boot by Physical Block Reallocation with e4rat

#20 2011-08-23 20:02:05

Re: faster boot by Physical Block Reallocation with e4rat

#21 2011-08-23 20:12:20

Re: faster boot by Physical Block Reallocation with e4rat

#22 2011-08-24 01:08:09

Re: faster boot by Physical Block Reallocation with e4rat

#23 2011-08-24 01:49:15

Re: faster boot by Physical Block Reallocation with e4rat

#24 2011-08-24 08:43:05

Re: faster boot by Physical Block Reallocation with e4rat

#25 2011-08-27 21:08:11

Re: faster boot by Physical Block Reallocation with e4rat

Board footer