I am really liking Virtualmin, but just got bitten, hard, by an
unexplained problem. Postfix started rejecting incoming mail, saying in
the logfile (/var/log/maillog)
status=bounced (can't create user output file)
Well after much gnashing of teeth, it turns out that the user (me) was
over quota. You can see this with:
# quota itsme.mydomain
Disk quotas for user itsme.mydomain (uid 536):
Filesystem blocks quota limit grace files quota limit grace
/dev/xvda 51200 51200 51200 73 0 0
Hmm... where are those extra files? Not anywhere in /home ... read on
--Turns out, if you leave the "Scan for viruses?" checked (under
"Enabled Features" on the "Edit Virtual Server" tab) then clamav will
scan incoming email for viruses... and nearly instantly kill your
default 50MB per-user quota... and this is nearly impossible to find,
but go look in /tmp and you'll find /tmp/clamav-somebignumber as
a directory with files (main.db, main.hdb, main.info, main.mdb,
main.ndb) and they will be, oh, 15 megabytes in size. Ugh. Disable
virus scanning and delete those files. Or else push your users' quotas
up by maybe 100MB for the per-user virus databases.
Maybe there's a way to have clamav keep a system-wide virus database
instead. That would be much more logical, it seems. Or how about
leaving that up to users.
I still haven't found where to make "Scan for viruses" off by default
for new domains.
You might also want to check the users' mail inboxes, which are
located at:
/home/domain/homes/username/Maildir
where domain is the username for the domain, and username is the
user's name inside the domain. You will recognize these because the POP
or IMAP login for that user is domain.username.
Once you know these few steps, setting up a LAMP
(Linux/Apache/MySQL/Perl-PHP) server on a Linode
(please use that link, as it includes my referral code) is insanely
simple:
First, starting with a freshly provisioned CentOS install, ssh into the
root account. First, update the base system --
`
yum update
`
I find it convenient to also install the console version of emacs:
`
yum install emacs-nox
`
Next, edit /etc/sysconfig/network and change the hostname. That file
is read at boot, so you might also want to set the hostname for the
current session:
`
hostname www.example.com
`
Download the install.sh script from http://www.virtualmin.com/download.html
into /usr/src ... and then execute it:
`
cd /usr/src # wget http://software.virtualmin.com/gpl/scripts/install.sh
sh install.sh
`
Then login, as root, to your new virtualmin configuration at your
linode's address: https://li99-999.members.linode.com:10000 where the
99-999 is replace with your linode's address (see the linode control
panel).
Install problem: awstats
Ran into this error message after install, when clicking the "Check
Your System" button --
The AWstats command /usr/share/awstats/wwwroot/cgi-bin/awstats.pl was
not found on your system.
Complicated by the fact that "yum install awstats" said it was already
installed. But where? "rpm -ql awstats" gives the answer... and then I
just copied it as follows:
# mkdir -p /usr/share/awstats/wwwroot/cgi-bin
# cp -a /var/www/awstats/awstats.pl /usr/share/awstats/wwwroot/cgi-bin
Install problem: clamd (after update)
NOTE: After installing Virtualmin updates, I got an error:
ERROR: Command rejected by clamd (wrong clamd version?)
which I resolved with:
# /etc/rc.d/init.d/clamd-virtualmin restart
Default settings when you configure
Under System Settings / Server Templates and then Default Settings --
Mail for Domain / Mail alias mode for alias domains: * Copy
aliases from target*. Catchall is the default! And you don't want
that. See also "Postfix relaying" below.
Spam Filtering / Automatically delete old spam? Yes, if older than
7 days (or as you desire)
BIND DNS Domain / Hostname to your preferred world-visible
hostname; SPF DNS disabled (until you configure each domain
manually)
Upgrading PHP and MySQL
This is one place where Centos 5.3 lags behind the times. If you need
PHP 5.2 or above, you will have to enable an alternate repository. As
of this writing, the "Centos Testing" repository contains a pre-release
version that does not include the mcrypt and memache modules -- a
real problem. NOTE: Although I was able to upgrade a running server,
I'd recommend doing this before loading any production domains. Follow
the instructions at
http://www.virtualmin.com/documentation/system/bleed
Double-Check Postfix Relaying
Postfix was accepting email for anything@aliased-domain.com ... to
solve this, open the aliased sub domain in Virtualmin, and under:
Server Configuration
Email Settings
change:
Virtual server email-related settings
Mail aliases mode
from Catchall forwarding to Copy aliases from target. You
probably want to change this on the System Settings / Server Templates
/ Default Settings for Sub-Servers page as well. If you have already
created several domains, you can adjust this all at once:
# virtualmin modify-mail --alias-copy --all-domains
NOTE: Is there a bug in Virtualmin 3.68.gpl? I had to manually:
# cd /etc/postfix
# postmap virtual
# postfix reload
to force that to refresh.
Tuning clamd
Rather than spend too much time tuning the memory, I simply killed
clamd as it is a huge memory pig and leads to Out Of Memory webserver
freezes.
Tuning Apache
With the default settings, Apache can veer out of control and eat all
available memory. In /etc/httpd/conf/httpd.conf, change as follows in
the section shown:
# prefork MPM
# StartServers: number of server processes to start
# MinSpareServers: minimum number of server processes which are kept spare
# MaxSpareServers: maximum number of server processes which are kept spare
# ServerLimit: maximum value for MaxClients for the lifetime of the server
# MaxClients: maximum number of server processes allowed to start
# MaxRequestsPerChild: maximum number of requests a server process serves
# was: MaxSpareServers 20 ServerLimit 256 MaxClients 256 MaxRequestsPerChild 400
0
<IfModule prefork.c>
StartServers 8
MinSpareServers 5
MaxSpareServers 10
ServerLimit 64
MaxClients 64
MaxRequestsPerChild 400
</IfModule>
Tuning Spamassassin
Dramatically reduce memory footprint by changing the number of threads
that spamassassin will execute at once from 5 down to 1. In /etc/sysconfig/spamassassin
(your location may vary) --
change:
SPAMDOPTIONS="-d -c -m<strong>5</strong> -H"
to
SPAMDOPTIONS="-d -c -m<strong>1</strong> -H"
-- William Lindley Automatically delete old spam?
No
Yes, if older than
daAutomatically delete old spam? No
Yes, if older than days
ys
http://www.yourdomain.com:2082 cPanel
https://www.yourdomain.com:2083 cPanel ssl
http://www.yourdomain.com:2086 WHM
https://www.yourdomain.com:2087 WHM ssl
http://www.yourdomain.com:2095 webmail
https://www.yourdomain.com:2096 webmail ssl
So I tried to install simutrans on Ubuntu 8.10 and get this
error message:
./simutrans/simutrans: error while loading shared libraries:
<strong>libSDL_mixer-1.2.so.0</strong>: cannot open shared object file:
No such file or directory
Note the filename I put in bold -- apt-get rejects commands like:
# <strong>apt-get install libSDL_mixer</strong>
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find package libSDL_mixer
Well, that's not too helpful. Apparently the package name isn't the
same as the file the loader is complaining about. How do we find it?
Try this to search the package database:
# <strong>apt-get install apt-file</strong>
# <strong>apt-file update</strong>
and then you will be able to do a search which returns useful results:
# <strong>apt-file search libSDL_mixer-1.2.so.0</strong>
<em>libsdl-mixer1.2</em>: /usr/lib/libSDL_mixer-1.2.so.0
<em>libsdl-mixer1.2</em>: /usr/lib/libSDL_mixer-1.2.so.0.2.6
Aha! What we want is libsdl-mixer1.2 (Different capitalization and a
hyphen instead of an underline, with the "-1.2" replaced by just
"1.2"... who thinks these things up?)
Finally we do:
# <strong>apt-get install libsdl-mixer1.2</strong>
and... success!
Full instructions, particularly for "headless" installation, are here.
First we download the RPM for RedHat Enterprise Linux 5 (RHEL 5) which
is the equivalent to Centos from the virtualbox.org site
After downloading (and renaming the file to eliminate everything after
the .rpm) we install as follows but get an error:
# rpm -ivh VirtualBox-2.1.0_(version).rpm
...
No precompiled module for this kernel found! ...
Compilation of kernel module FAILED! ...
Please consult
/var/log/vbox-install.log
to find out why the kernel module does not compile.
Most probably the kernel sources are not found.
Install them and execute
<strong>/etc/init.d/vboxdrv setup</strong>
as root.
To rectify this:
# yum install SDL kernel-devel kernel-headers
# KERN_DIR=/usr/src/kernels/2.6.18-whatever-your-current-kernel
# export KERN_DIR
# /etc/init.d/vboxdrv setup
Then add users to the vboxusers group:
# /usr/sbin/usermod -a -G vboxusers yourusername
and you should be able to launch VirtualBox from the Applications /
System Tools menu.
Have fun!