Step 1.) Upgrade to Debian 11 first
The process to go to Debian 12 is not as smooth as 11, when trying to upgrade from Debian 10. In fact, it doesn't work directly, so you'll first need to follow this guide to update to Debian 11, reboot and come back here if successful.
Step 2.) Update sources.list
Update your /etc/apt/sources.list like this:
deb http://........
In this example we install debian 10 with --variant=minbase which gives us a minimal/tiny install. Don't use variant if you want the full size install.
mkdir /tmp/deb10files
debootstrap --variant=minbase buster /tmp/deb10files/
Did you get an error?
debootstrap --variant=minbase buster /home/theuser/VMs/deb10files/
You'll get this error if you make a directory in your home........
Sometimes due to your BIOS/EFI you may find that you have chosen "Energy Efficient" for your CPU which may effectively disable turbo mode. This is because "Energy Efficient" will often restrict or throttle your CPU to the base speed. This can impact nearly any CPU such as Intel's, AMDs, Opteron, Xeon etc...
This is of course frustrating, for example if you have a CPU that is 2.0GHz base speed but turbo to 2.5GHz, you will never hit more than 2GHz.........
Bonding is an excellent way to get both increased redundancy and throughput. It is similar to the "Network Teaming" feature in Windows.
There are a few different modes but we will use mode 6, I think it's the best of both worlds, as it is not just a failover, but it provides round robin, so you will get redundancy and load balancing. So if you have a 1G single port, you will have a combined throughput of 4G at this point. Just bear in mind that the true thr........
I used to believe that for Desktops especially that the "ondemand" CPUfrequency changing that kernels included with Ubuntu and Debian based distros have would be sufficient for snappy performance.
However, you can feel the lack of performance on the fastest computer if you have ondemand. A lot of times even under high load 100% of your CPUfrequency in MHz will not be used.
For example a 2.8Ghz CPUmay only run at 1.8MHz or even .9GHz. Now........
It is almost as intuitive as we would like it is just a *.
So literally:
*INA 127.0.0.1
Complete working bind zonefile below:
$TTL 86400
@ IN SOA ns.rtt.ca. ns2.rtt.ca. (
1247605715; Serial
&n........
A lot of people just have a -j DROP to drop all unwanted traffic or traffic not explicitly allowed but there is a better solution if you want real and proper logging:
Here is another example of more advanced iptables rules.
Take an example iptables rules file
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -i eth1 -p icmp -j ACCEPT........
Do you hate it when your ISPhas old cached records because of a high TTLon the DNS record of the relevant domain? In plain English this means you often can't connect to a site or service because your ISP's DNS servers haven't gotten word of the new IP address (probably because they haven't checked). There are also some that are notorious for ignoring TTL and not updating records for days!
But if you are lucky and smart enough to have your own Linux based DNS se........
Jul 3 22:12:17mailserver postfix/smtpd[6195]: fatal: no SASL authentication mechanisms
Jul 3 22:12:18mailserver postfix/master[4881]: warning: process /usr/libexec/postfix/smtpd pid 6195 exit status 1
Jul 3 22:12:18mailserver postfix/master[4881]: warning: /usr/libexec/postfix/smtpd: bad command startup -- throttling
This only ever happens in my experience when the authentication method is actually Dovecot. Usually the problem........
Centos when copying old files and restarting it seems load everything fine and then says [FAILED] with no log or other message.
service restart named
named [FAILED]
Check more thoroughly you may have missed the error if you have lots of zones!
service named restart|grep error
zone 1.168.192.in-addr.arpa/IN: not loaded due to errors.
zone 2.168.192.in-addr.arpa/IN: no........
I wanted to use Astrachat because it seems to be the only app that has video, pic and file sharing for Jabber butI cannot even connect despite any other client working fine including Xabber and others.
astrachat "Oops.. We can't connect to the account that you provide above. Please recheck your account detail".
Unfortunately to make it worse there doesn't seem to be any error log or more details about the issue.
The jab........
I am getting this error:
kernel:[14277.697049] EDAC MC0: UE row 4, channel-a= 0 channel-b= 1 labels "-": (Branch=0 DRAM-Bank=0 RDWR=Read RAS=7048 CAS=0 FATAL Err=0x4 (>Tmid Thermal event with intelligent throttling disabled))
But many people believe this is a bug/false message and the server is running stably.........
ip tunnel add tun3 mode gre remote 192.58.1.5 ttl 64
ioctl: no such device
I solved this on Centos by loading the ip_gre module:
modprobe ip_gre
On Debian I believe it is the "sit" module.........
iptables v1.3.5: can't initialize iptables table `nat': Table does not exist (do you need to insmod?)
This solution applies to all other iptables modules/problems for OpenVZ, you'll just need to add them to both lists/lines below if you have modules other than what I have below.
The modules need to be enabled in both iptables and the OpenVZ hostnode itself and then the containers which need it must be restarted.
How To Enable IPTables Modules in OpenVZ........
I thought only a faster CPUand SSDwould help but I already have a Quad-Core CPU and it wasn't being maxed out. The actual tests were performed on an AMD-V enabled 128MB dual core VMWare container though.
There is a flag that can be passed to make in order to start multiple threads, by specifying 4 threads I was able to reduce the whole kernel compilation time from scratch by about 50%! (65minutes vs 31minutes!). *Yes I did do a make clean before each co........
Centos 5 Postfix and SPAMASSASSIN Tutorial
yum install spamassassin
chkconfig spamassassin on
vi /etc/mail/spamassassin/local.cf
##############
#required_hits 5
#report_safe 0
#rewrite_header Subject [SPAM]
#5 is the least restrictive (means only the most obvious SPAM is caught. 0 is obviously the most restrictive/sensitive and would have lots of false positives
require........
That is pinging to the gateway IP on the same switch, the same IP is pingable externally without any problems which makes me think the switch is fine.
64 bytes from 55.55.55.55: icmp_seq=4 ttl=255 time=1.07 ms
64 bytes from 55.55.55.55: icmp_seq=1 ttl=255 time=3536 ms
64 bytes from 55.55.55.55: icmp_seq=2 ttl=255 time=2536 ms
64 bytes from 55.55.55.55: icmp_seq=3 ttl=255 time=1536 ms
64 bytes from 55.55.55.55: icmp_seq=8 ttl=255 time=1.20 ms
64 by........
The default options for iptables are very basic. Here is what you need to do in order to enable them in OpenVZ.
1.) Add the modules to iptables and restart iptables:
vi /etc/sysconfig/iptables-config
Edit the line as so:
IPTABLES_MODULES="ipt_REJECT ipt_tos ipt_TOS ipt_LOG ip_conntrack ipt_limit ipt_multiport iptable_filter iptable_mangle ipt_TCPMSS ipt_tcpmss ipt_ttl ipt_length ipt_state iptable_nat ip_nat_ftp"
2.........