Check Ubuntu swap is allocated
swapon -s
Checks what paths are currently accepted for swap
Ubuntu wrong disk size with DF
Is your linux reporting the wrong disk size after expanding the disk?
get this: http://www.sysresccd.org/
1. Boot you system with a CDROM/USB using any of the rescue linux or knoppix etc. I used sysresccd.
2. After boot up
umount /dev/sda3 (just in case if it is mounted)
3. do a file system check
Code:
fsck -n /dev/sda3
Output shuld be
/dev/sda3: clean, >
4.Removed the journal from /dev/sda3, this will make it an ext2 partition
tune2fs -O ^has_journal /dev/sda3
5. run
e2fsck -f /dev/sda3
6. resize the partition (with resize2fs without options takes your max size of the disk)
resize2fs /dev/sda3
7. Next run
fsck -n /dev/sda3
8. Create journal on /dev/sda3, this will turn sda3 to ext3 partition again
Code:
tune2fs -j /dev/sda3
9. Reboot the system using your original OS
Proftpd and TLS
OpenSSL is needed by TLS; to install ProFTPd and OpenSSL, we simply run:
apt-get install proftpd openssl
You will be asked a question:
Run proftpd: <-- standalone
Creating The SSL Certificate For TLS
In order to use TLS, we must create an SSL certificate. I create it in /etc/proftpd/ssl, therefore I create that directory first:
mkdir /etc/proftpd/ssl
Afterwards, we can generate the SSL certificate as follows:
openssl req -new -x509 -days 365 -nodes -out /etc/proftpd/ssl/proftpd.cert.pem -keyout /etc/proftpd/ssl/proftpd.key.pem
Country Name (2 letter code) [AU]: <-- Enter your Country Name (e.g., "DE").
State or Province Name (full name) [Some-State]: <-- Enter your State or Province Name.
Locality Name (eg, city) []: <-- Enter your City.
Organization Name (eg, company) [Internet Widgits Pty Ltd]: <-- Enter your Organization Name (e.g., the name of your company).
Organizational Unit Name (eg, section) []: <-- Enter your Organizational Unit Name (e.g. "IT Department").
Common Name (eg, YOUR name) []: <-- Enter the Fully Qualified Domain Name of the system (e.g. "server1.example.com").
Email Address []: <-- Enter your Email Address.
4 Enabling TLS In ProFTPd
In order to enable TLS in ProFTPd, open /etc/proftpd/proftpd.conf...
vi /etc/proftpd/proftpd.conf
... and uncomment the Include /etc/proftpd/tls.conf line:
[...]
## This is used for FTPS connections
#
Include /etc/proftpd/tls.conf
[...]
Then open /etc/proftpd/tls.conf and make it look as follows:
<IfModule mod_tls.c>
TLSEngine on
TLSLog /var/log/proftpd/tls.log
TLSProtocol SSLv23
TLSOptions NoCertRequest
TLSRSACertificateFile /etc/proftpd/ssl/proftpd.cert.pem
TLSRSACertificateKeyFile /etc/proftpd/ssl/proftpd.key.pem
TLSVerifyClient off
TLSRequired on
</IfModule>
If you use TLSRequired on, then only TLS connections are allowed (this locks out any users with old FTP clients that don't have TLS support); by commenting out that line or using TLSRequired off both TLS and non-TLS connections are allowed, depending on what the FTP client supports.
Restart ProFTPd afterwards:
/etc/init.d/proftpd restart
That's it. You can now try to connect using your FTP client; however, you should configure your FTP client to use TLS (this is a must if you use TLSRequired on) - see the next chapter how to do this with FileZilla.
If you're having problems with TLS, you can take a look at the TLS log file /var/log/proftpd/tls.log.
Linux commands to test website speed
ngrep -q 'HTTP Error 503' port 80
this command gets all trafic on eth0 and on port 80 that includes the line "HTTP Error 503"
tcpdump -i eth0
gets tcp traffic on eth0
ulimit -n 300000
Sets the max numbers of open files
ab -n 100000 -c 500 http://blog.hviidnet.com/
Benchmarks blog.hviidnet.com with 500 concurent connections 100000 times.. (needs to have apache installed)
Ubuntu 8.04 network after vmware ESX 3i clone
vi /etc/udev/rules.d/70-persistent-net.rules
when you clone a vm, it will assign the nic a new mac.
if you didn’t clear these rules prior to cloning the disk, the mac will be assigned to the next available ethernet interface ie: eth1
delete the eth0 line, rename the eth1 to eth0, reboot.
Alteratively just delete the file. For template clone images just delete the file as the last thing you do and it will create a new on boot (when its cloned and has new mac addresses).