 www.centos.org Forum Index CentOS 5 - General Support  Optimizing Boot Time
|
 Bottom  Previous Topic  Next Topic |
|
|
|
|
|---|
Topic options
Threaded
Newest First| Poster | Thread |
|---|
|
Optimizing Boot Time | #1 |
|
|---|---|---|---|
|
Jr Board Member
 
Joined: 2010/8/30
From
Posts: 28
|
On a fast computer, it takes me slightly over 2 minutes to reach the login screen. What I found was that there are 3 things are slowing up the process:
1- There is a message "Reading all Physical Volumes, This might take a while"; This takes about 25 seconds. Is there a way to automaticall skip this? 2- There is a message "Determining IP Information for eth0. This takes about 15 seconds. Is there a way to optimize this? 3- There are many services loaded at the end of the boot process that take up time. How can I get a list of services, determine which are not relevant, and tell Centos not to load them at boot time? Thank you for your help. |
||
Posted on: 2010/9/12 8:46
  |
 |
||
curtis1000
|
Re: Optimizing Boot Time | #2 |
|
|---|---|---|---|
|
Moderator
Joined: 2007/9/3
From NYC
Posts: 1502
|
For the services, you can use the command
chkconfig --list |grep on This will also list anything with "on" in its name, but it will show you what services are running at boot. Like Windows, it will start up just about everything installed. For an idea of what each of these services do, your best bet is to probably go to the mjmwired.net site and look for the Fedora 5 or 6 guides, where the author gives a listing of most of the services with an explanation of what they do. You can try searching through the RedHat guides too, but their explanations are usually harder to find and pretty bad--this is a made up example for effect, but it will often be along the lines of avahi. This starts the avahi daemon. Whereas, the mjmwired guides will actually <gasp> add a few words saying what the avahi daemon does. |
||
|
_________________
New users should read FAQ & Readme First |
|||
Posted on: 2010/9/12 10:02
|
|
||
|
Re: Optimizing Boot Time | #3 |
|
|---|---|---|---|
|
Jr Board Member
Joined: 2010/8/30
From
Posts: 28
|
Thanks. I am running Centos as a Desktop Environment. Basically using Productivity Applications and connecting to via DSL for internet browsing / email. Here is the list of processes that are preloaded. Do you see any obvious ones that don't belong?
acpid anacron atd auditd autofs avahi-daemon avahi-dnsconfd conman cpuspeed crond cups firstboot gpm haldaemon hidd hplip iptables irqbalance isdn kdump kudzu lvm2-monitor mcstrans mdmonitor messagebus microcode_ctl netconsole netfs network nfslock pcscd portmap rawdevices readahead_early readahead_later restorecond rhnsd rpcgssd rpcidmapd sendmail setroubleshoot smartd sshd syslog wdaemon xfs yum-updatesd |
||
Posted on: 2010/9/12 10:58
|
|
||
|
Re: Optimizing Boot Time | #4 |
|
|---|---|---|---|
|
Moderator
Joined: 2006/12/13
From Tidewater, Virginia, North America
Posts: 18773
|
Quote:
Or, as there are a number of services that have "on" in the name which may actually be "off" by default, to get only services that are actually on |
||
|
_________________
Phil Recommended reading: FAQ & Readme first ; Search hint: google "your topic site:centos.org"; Smart Questions |
|||
Posted on: 2010/9/12 11:02
|
|
||
|
Re: Optimizing Boot Time | #5 |
|
|---|---|---|---|
|
Moderator
Joined: 2006/12/13
From Tidewater, Virginia, North America
Posts: 18773
|
Quote:
Hard for anyone else to guess what you do or don't need, as it depends on what you are doing with the system, but AFAIK rhnsd only exists on Red Hat systems, not on CentOS. |
||
|
_________________
Phil Recommended reading: FAQ & Readme first ; Search hint: google "your topic site:centos.org"; Smart Questions |
|||
Posted on: 2010/9/12 11:08
|
|
||
|
Re: Optimizing Boot Time | #6 |
|
|---|---|---|---|
|
Jr Board Member
Joined: 2010/8/30
From
Posts: 28
|
Understood.
Any ideas on how I can get the startup routine to skip the time consuming "Reading All Physical Volumes" step? |
||
Posted on: 2010/9/12 11:25
|
|
||
|
Re: Optimizing Boot Time | #7 |
|
|---|---|---|---|
|
Moderator
Joined: 2006/12/13
From Tidewater, Virginia, North America
Posts: 18773
|
I believe doing that would be very likely to break your system. Most CentOS systems are not rebooted all that often, so optimizing boot time may rapidly reach a point of diminishing returns. Optimizing services has a much greater payoff as it will help with performance as well as boot time.
|
||
|
_________________
Phil Recommended reading: FAQ & Readme first ; Search hint: google "your topic site:centos.org"; Smart Questions |
|||
Posted on: 2010/9/12 11:33
|
|
||
|
Re: Optimizing Boot Time | #8 |
|
|---|---|---|---|
|
Moderator
Joined: 2007/10/22
From ~/Earth/UK/England/Suffolk
Posts: 9131
|
Quote:
Yes. Oh, you want me to type some more?  O.k. -- Your system was installed using LVM, hence all Physical Volumes have to be read at system boot time. To dispense with that step requires you to dispense with the use of LVM. So backup all of your data and then re-install the OS, ensuring that you de-select the use of LVM. Finally restore all of your data. |
||
Posted on: 2010/9/12 16:55
|
|
||
|
Re: Optimizing Boot Time | #9 |
|
|---|---|---|---|
|
Jr Board Member
Joined: 2010/8/30
From
Posts: 28
|
Yes Alan, I want you to type more :) It helps me become more literate.
Two questions, -Before I backup my data and reinstall, are there any compelling reasons why I should be using LVM? -If I look at my startup process, I see that the 2 minutes can be broken down roughly as follows: 1- 50 seconds - LVM 2- 40 seconds - Determining IP info for ETH0 and then setting up and connecting to DSL 3 - 30 seconds - Starting up services, udev, etc.) Is there anything that can be done to the second item? |
||
Posted on: 2010/9/12 19:05
|
|
||
|
Re: Optimizing Boot Time | #10 |
|
|---|---|---|---|
|
Moderator
Joined: 2007/10/22
From ~/Earth/UK/England/Suffolk
Posts: 9131
|
Quote:
It's really a personal / system requirements decision. For example, my (static) workstation. As it is a reuse of (refurbished) hardware of over eleven years of age (the "trailing edge" of hardware) and only has PATA (EIDE) disk interfaces both small (physical) disks are "stitched" together by LVM to provide one logical, larger, disk. On the other hand my laptop, just a few months old with one average sized SATA disk, does not use LVM -- it isn't even installed. That is just a personal view with a couple of "personal" systems. Others will be able to explain the many benefits of LVM when used with a multi-disk server. Quote:
That seems to be excessive, to me.  My workstation, above, take no more than 5 seconds. It is configured to use a static link between the workstation and the switch / router / modem. (The ADSL link between the modem and the DSLAM is configured as DHCP.) Please post the output returned by ./getinfo.sh network, as detailed in How To Provide Information About Your System . . . |
||
Posted on: 2010/9/12 19:43
|
|
||
|
Re: Optimizing Boot Time | #11 |
|
|---|---|---|---|
|
Moderator
Joined: 2006/12/13
From Tidewater, Virginia, North America
Posts: 18773
|
Quote:
My suspicion would be on what's on the other end of the wire - DSL modem, router, DHCP server, DNS, ISP. |
||
|
_________________
Phil Recommended reading: FAQ & Readme first ; Search hint: google "your topic site:centos.org"; Smart Questions |
|||
Posted on: 2010/9/12 20:10
|
|
||
|
Re: Optimizing Boot Time | #12 |
|
|---|---|---|---|
|
Jr Board Member
Joined: 2010/8/30
From
Posts: 28
|
I can understand 10 to 15 seconds needed to setup and connect the DSL connection, what I don't understand is why it takes often 20 seconds to "Determine IP information for ETH0"
I tried posting at the pastebin, but the captcha doesn't appear (probably a problem with my company's web filter.) So, I can just paste here, what is relevant (or not), sorry about the length |
||
Posted on: 2010/9/12 20:45
|
|
||
|
Re: Optimizing Boot Time | #13 |
|
|---|---|---|---|
|
Moderator
Joined: 2007/10/22
From ~/Earth/UK/England/Suffolk
Posts: 9131
|
Quote:
I asked you to make it available, so please don't worry about its length. Quote:
Exactly, Phil. Whatever it is, the system is configured, DHCP-wise, to talk to it and it's waiting for the device's response that accounts for the delay. So, the advice is to check the configuration of the device at the other end of the Ethernet cable. If at all possible, try a static configuration. |
||
Posted on: 2010/9/12 22:17
|
|
||
|
Re: Optimizing Boot Time | #14 |
|
|---|---|---|---|
|
Jr Board Member
Joined: 2010/8/30
From
Posts: 28
|
I changed the ETH0 connection from Dynamic to Static; now it only takes 5 seconds for ETH0 to be loaded and activated at startup! Thanks Alan and Phil!
Next step....removing LVM and reinstalling in the most efficient way. I foolishly let Centos decide how to partition my HD, so it put everything on one 100G partition. The newbie asks "Is there a way, I can shrink this partition, create a new partition, copy everything that is in my /home folder to the new partition, and reinstall Centos on the original partition?" |
||
Posted on: 2010/9/13 10:37
|
|
||
|
Re: Optimizing Boot Time | #15 |
|
|---|---|---|---|
|
Moderator
Joined: 2007/10/22
From ~/Earth/UK/England/Suffolk
Posts: 9131
|
I think it will now be necessary for you to show us the output produced by ./getinfo.sh disk, when executed with root's powers . . .
Do you already have more data than the capacity of one DVD in your home partition to backup? Could you borrow an external USB drive to act as a temporary data repository? |
||
Posted on: 2010/9/13 14:27
|
|
||
|
Re: Optimizing Boot Time | #16 |
|
|---|---|---|---|
|
Jr Board Member
Joined: 2010/8/30
From
Posts: 28
|
Here is the relevant output:
I can backup the most important files (i.e. docs, mail, music, pictures) to my 8gb flash disk; but I have no DVD write capability nor room to back up anything else. I was hoping that there would be a little magic available. |
||
Posted on: 2010/9/13 19:18
|
|
||
|
Re: Optimizing Boot Time | #17 |
|
|---|---|---|---|
|
Moderator
Joined: 2007/10/22
From ~/Earth/UK/England/Suffolk
Posts: 9131
|
Quote:
Right, understood. With your 8 GB flash disk you've already got ~1.7 times the capacity of a standard DVD.  Magic is available via these fora -- but not from this Wizard, as my knowledge of LVM is extremely limited. I wonder who will be the first to offer some guidance -- Phil, perhaps? |
||
Posted on: 2010/9/14 0:31
|
|
||
|
Re: Optimizing Boot Time | #18 |
|
|---|---|---|---|
|
Moderator
Joined: 2006/12/13
From Tidewater, Virginia, North America
Posts: 18773
|
Not sure what magic is desired. If it is to convert LVM to just a plain ext3 partition, without reinstalling or losing data, that is beyond my magical powers.
Frankly, I'd just wait the extra time for the boots, and optimize overall time usage by doing something else during that minute or two; rather than spending hours to potentially days, in the case of difficulty and/or getting up the learning curve, backing up, reinstalling, restoring, and configuring. |
||
|
_________________
Phil Recommended reading: FAQ & Readme first ; Search hint: google "your topic site:centos.org"; Smart Questions |
|||
Posted on: 2010/9/14 17:54
|
|
||
|
Re: Optimizing Boot Time | #19 |
|
|---|---|---|---|
|
Jr Board Member
Joined: 2010/8/30
From
Posts: 28
|
Thanks Phil.
I decided to go for a full reinstall because WebCam is a show stopper. Relatives that live overseas and want to see us on Skype. In VirtualBox the camera didn't work (it has no problems in Windows) so I am going to try installing the 32bit version of Centos (it is rumored that webcams live better in that environment) if that doesn't work, I will have to setup a dual boot system with Windows. |
||
Posted on: 2010/9/14 18:46
|
|
||
|
Re: Optimizing Boot Time | #20 |
|
|---|---|---|---|
|
Moderator
Joined: 2006/12/13
From Tidewater, Virginia, North America
Posts: 18773
|
If you have webcam problems that should be discussed in another thread - first mention of that or VirtualBox here (or there - if relevant it should have been mentioned). USB is somewhat problematic in VB on a CentOS host. See http://wiki.centos.org/HowTos/Virtualization/VirtualBox
|
||
|
_________________
Phil Recommended reading: FAQ & Readme first ; Search hint: google "your topic site:centos.org"; Smart Questions |
|||
Posted on: 2010/9/14 19:56
|
|
||
 Top Previous Topic Next Topic |
 |
|
You cannot start a new topic.
You can view topic.