This will be the goto to help solve e-mail delivery issues and talk about many practical issues that happen between developers, admins and scripts that send e-mail and do things that may not be acceptable or cause deliverability problems.
Sendmail Stuff
Edit /etc/mail/sendmail.mc
The problem is that if you send directly out from the server using the mail function, the Return-path of the e-mails will be username@thehostnameoftheserver.com. Let........
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://........
It is a bit different and annoying here for these types of routers/models as you need to physically remove the CF (Compact Flash) and only then, will it enter ROMMON mode (Ctrl + Pause remotely over the console will not do it for us). This means you cannot do this remotely, or at least not without the help of a remote/physical helper.
Step 1.) Power off, router and remove CF Disk Slot#2
Go to the router and remove the slot#2 cover uses your hand or it may help to use a........
If you can print other PDFs but not a particular one it is very likely that the PDF size is A4 (the longer, skinnier Asian paper size) instead of the North American letter size ( 8.5" x 11"). This breaks printing in most cases. Or it may print if you find a program that ignores the size issue.
Here is an example of an A4 being rejected by a printer in Ubuntu Linux via CUPS
Cannot print PDF CUPS Samsung C460:
Processin........
[root@localhost:~]
BootModuleConfig.sh echo host-ind nfcd........
Many people are aware of the "eject command" which works as you would expect.
To eject the disc:
sudo eject /dev/sr0
To insert the disc again you still use the same command but with the "-t" close try toggle:
sudo eject -t /dev/sr0
........
#if you have nvidia make sure you install the nvidia-cuda-toolkit so hardware acceleration can be used
wget http://ffmpeg.org/releases/ffmpeg-3.3.2.tar.bz2
tar -jxvf ffmpeg-3.3.2.tar.bz2
cd ffmpeg-3.3.2/
./configure --disable-yasm
install prefix /usr/local
source path ........
The Scenario
You have dual NICs and you disable NIC1 which uses 192.168.1.1 as its gateway. With NIC2 you enable it/connect it to another network which also has the gateway 192.168.1.1
Everything will work fine at this point.
When switching back to NIC1 even with NIC2 disabled and even unplugged, the OS basically can't pick up the new/updated ARP entry of the old device for 192.168.1.1 and perhaps thinks it is a security risk or spoof of some sorts and blocks i........
[3805108.257042] sd 0:0:0:0: [sda] 1953525168 512-byte hardware sectors: (1.00 TB/931 GiB)
[3805108.257052] sd 0:0:0:0: [sda] Write Protect is off
[3805108.257054] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00
[3805108.257066] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[3805108.257083] sd 0:0:0:0: [sda] 1953525168 512-byte hardware sectors: (1.00 TB/931 GiB)
[3805108.257090] sd 0:0:0:0: [sda] Write Protect is off........
One thing to remember is that you need MegaCli to do the flashing.
You also need the correct file,I tried at least 2 different Perc 6 firmwares from Dell that kept getting rejected as corrupt by MegaCli(they were really the wrong version). I have an external PCI-E Dell 6 Perc/I butI chose images from the 'Integrated" on motherboard version as it was allI could find. They are different, and below is my first time finding success.........
Jul 11 15:20:58 tor sendmail[9617]: r6AKjOD07: to=
mailserver.com was the hostname of the server, sendmail sends this by default and many mailservers will reject mail to a hostname that does not resolve or exist.
The easiest way is just to change the hostname and make sure it does resolve to something.
I read there is a way in sendmail.mc to manually set a hostname but I never got it working:
vi /etc/mail/sendmail.mc
define(`confDOMAIN........
This is a handy link and list of all the relevant Directadmin log files and related servers.
http://help.directadmin.com/item.php?id=11
DirectAdmin:
/var/log/directadmin/error.log
/var/log/directadmin/errortaskq.log
/var/log/directadmin/system.log
/var/log/directadmin/security.log
Apache:........
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........
For years I've always built cheap systems believing that there is little difference in more expensive components when it comes to reliability and quality, I generally believe this still except for Power Supplies.
I've always bought cheap cases with nice sounding 350-550W stock/cheap/crap power supplies and haven't had any issues for the most part until recently.
One such case is an NGEAR case with a 550W Optimax power supply, I always read that these supplies don't produce the........
This is a very basic method and won't work in all cases but will reduce the chance of torrenting/abuse by your server users.
iptables -A INPUT -p tcp --destination-port 6881:6999 -j REJECT
iptables -A OUTPUT -p tcp --source-port 6881:6999 -j REJECT........
I'm posting this because it wasn't easy or obvious how this would be accomplished and the man page leaves it to guesswork.
Multi-line body_checks
Example 1
/........
Affected rows: 0
Warning: #1264 Out of range value adjusted for column 'deleteon' at row 1
SQL query:
UPDATE `custtable`.`custinfo` SET `deleteon` = '2011-02-29 00:00:00' WHERE `custinfo`.`custid` =105 LIMIT 1 ;
This happened after a migration to a new SQL database due to user error. The old database server MySQL 3.23 or 4 allowed an impossible date to be entered by a user. As we know February 29th DOESNOT exist but the database al........
Basically you should always be 100% sure that whatever IPyour mail server sends out with has reverse DNS/PTR records. Remember that unless you own your IPs then you won't be able to set your own reverse DNS. Even if you were to create a reverse PTR record on your DNS servers it will be ignored. Reverse DNS is queried to pre-assigned DNS servers of your ISP, so therefore you'll need to contact your ISP/Colo/Hosting provider to do a reverse DNS entry.
If you don't have........
Create Cert & Key:
openssl req -new -x509 -nodes -days 1530 -out server.crt -keyout server.key
mkdir /etc/mailssl
chmod 700 /etc/mailssl
cp server.* /etc/mailssl
Postfix SSL config
Edit /etc/postfix/main.cf:
#SSL stuff
smtpd_tls_cert_file = /etc/mailssl/server.crt
smtpd_tls_key_file = /etc/mailssl/server.key
To make smtps w........
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.........