I'm a bit partial to Zen Load Balancer. As a matter of a fact, I love it. It has many, many things ready to go from the start.
And it being just a Debian distro with the zenloadbalancer package on top, there's a lot you can do to customize it. The first thing we need to do is get rid of this:
My system has 16GB of memory but memory reported is just 3GB? Yup.
See Zen Load Balancer is a 32-bit app and it is distributed with a 32-bit Debian distro.
Assuming we have a 64-bit system with more memory installed we'll need to upgrade the kernel to a PAE one. This is both a performance and a security enhancement. It will allow us to use more memory and will also enable NX protection (provided that our BIOS and CPU support it too), as the NX bit works on the 63rd bit of the address.
Editing our repos first:
Let's try to upgrade our kernel now:
Yeah ok, classic Debian thing:
One more time for the world:
Right, let's be conservative and upgrade to a 2.6 PAE kernel, we'll do a major upgrade later:
All right, so did it work?
Looks good. And what about NX?
Cool. Let's go on then. Let's do a distro upgrade from Squeeze to Wheezy:
Indeed:
And it being just a Debian distro with the zenloadbalancer package on top, there's a lot you can do to customize it. The first thing we need to do is get rid of this:
My system has 16GB of memory but memory reported is just 3GB? Yup.
See Zen Load Balancer is a 32-bit app and it is distributed with a 32-bit Debian distro.
Assuming we have a 64-bit system with more memory installed we'll need to upgrade the kernel to a PAE one. This is both a performance and a security enhancement. It will allow us to use more memory and will also enable NX protection (provided that our BIOS and CPU support it too), as the NX bit works on the 63rd bit of the address.
Editing our repos first:
root@zen-lb:~# vi /etc/apt/sources.list#official repository for Debian
deb http://ftp.debian.org/debian/ stable main non-free
deb-src http://ftp.debian.org/debian/ stable main non-free
deb http://security.debian.org/ stable/updates main
deb-src http://security.debian.org/ stable/updates main
#official repository for Zen Load Balancer Updates
deb http://zenloadbalancer.sourceforge.net/apt/x86 v3/
#Let's add this repo as well to do a moderate PAE upgrade at first
deb http://security.debian.org/debian-security squeeze/updates main
Let's try to upgrade our kernel now:
root@zen-lb:~# apt-get update....
....
....
Reading package lists... Done
W: GPG error: http://ftp.debian.org stable Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 8B48AD6246925553 NO_PUBKEY 6FB2A1C265FFB764
W: GPG error: http://security.debian.org stable/updates Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 8B48AD6246925553
Yeah ok, classic Debian thing:
root@zen-lb:~# gpg --keyserver pgpkeys.mit.edu --recv-key 6FB2A1C265FFB764
root@zen-lb:~# gpg -a --export 6FB2A1C265FFB764 | apt-key add -
root@zen-lb:~# gpg --keyserver pgpkeys.mit.edu --recv-key 8B48AD6246925553
root@zen-lb:~# gpg -a --export 8B48AD6246925553 | apt-key add -
root@zen-lb:~# apt-get updateFetched 548 kB in 1s (444 kB/s)
Reading package lists... Done
One more time for the world:
root@zen-lb:~# apt-cache search linux-imagelinux-image-2.6-486 - Linux for older PCs (dummy package)
linux-image-2.6-686 - Linux for modern PCs (dummy package)
linux-image-2.6-686-bigmem - Linux for PCs with 4GB+ RAM (dummy package)
linux-image-2.6-686-pae - Linux for modern PCs (dummy package)
linux-image-2.6-amd64 - Linux for 64-bit PCs (dummy package)
linux-image-486 - Linux for older PCs (meta-package)
linux-image-686 - Linux for modern PCs (dummy package)
linux-image-686-bigmem - Linux for PCs with 4GB+ RAM (dummy package)
linux-image-686-pae - Linux for modern PCs (meta-package)
linux-image-amd64 - Linux for 64-bit PCs (meta-package)
linux-image-rt-686-pae - Linux for modern PCs (meta-package), PREEMPT_RT
linux-image-3.2.0-4-486 - Linux 3.2 for older PCs
linux-image-3.2.0-4-686-pae - Linux 3.2 for modern PCs
linux-image-3.2.0-4-686-pae-dbg - Debugging symbols for Linux 3.2.0-4-686-pae
linux-image-3.2.0-4-amd64 - Linux 3.2 for 64-bit PCs
linux-image-3.2.0-4-rt-686-pae - Linux 3.2 for modern PCs, PREEMPT_RT
linux-image-3.2.0-4-rt-686-pae-dbg - Debugging symbols for Linux 3.2.0-4-rt-686-pae
linux-headers-2.6.32-5-486 - Header files for Linux 2.6.32-5-486
linux-headers-2.6.32-5-686 - Header files for Linux 2.6.32-5-686
linux-headers-2.6.32-5-686-bigmem - Header files for Linux 2.6.32-5-686-bigmem
linux-headers-2.6.32-5-amd64 - Header files for Linux 2.6.32-5-amd64
linux-headers-2.6.32-5-openvz-686 - Header files for Linux 2.6.32-5-openvz-686
linux-headers-2.6.32-5-vserver-686 - Header files for Linux 2.6.32-5-vserver-686
linux-headers-2.6.32-5-vserver-686-bigmem - Header files for Linux 2.6.32-5-vserver-686-bigmem
linux-headers-2.6.32-5-xen-686 - Header files for Linux 2.6.32-5-xen-686
linux-image-2.6.32-5-486 - Linux 2.6.32 for old PCs
linux-image-2.6.32-5-686 - Linux 2.6.32 for modern PCs
linux-image-2.6.32-5-686-bigmem - Linux 2.6.32 for PCs with 4GB+ RAM
linux-image-2.6.32-5-686-bigmem-dbg - Debugging infos for Linux 2.6.32-5-686-bigmem
linux-image-2.6.32-5-amd64 - Linux 2.6.32 for 64-bit PCs
linux-image-2.6.32-5-openvz-686 - Linux 2.6.32 for modern PCs, OpenVZ support
linux-image-2.6.32-5-openvz-686-dbg - Debugging infos for Linux 2.6.32-5-openvz-686
linux-image-2.6.32-5-vserver-686 - Linux 2.6.32 for modern PCs, Linux-VServer support
linux-image-2.6.32-5-vserver-686-bigmem - Linux 2.6.32 for PCs with 4GB+ RAM, Linux-VServer support
linux-image-2.6.32-5-vserver-686-bigmem-dbg - Debugging infos for Linux 2.6.32-5-vserver-686-bigmem
linux-image-2.6.32-5-xen-686 - Linux 2.6.32 for modern PCs, Xen dom0 support
linux-image-2.6.32-5-xen-686-dbg - Debugging infos for Linux 2.6.32-5-xen-686
Right, let's be conservative and upgrade to a 2.6 PAE kernel, we'll do a major upgrade later:
root@zen-lb:~# uname -aLinux zen-lb 2.6.32-5-686 #1 SMP Wed Jan 12 04:01:41 UTC 2011 i686 GNU/Linuxroot@zen-lb:~# apt-get install linux-image-2.6.32-5-686-bigmemGet:1 http://ftp.debian.org/debian/ stable/main linux-base all 3.5 [34.3 kB]
Get:2 http://security.debian.org/debian-security/ squeeze/updates/main linux-image-2.6.32-5-686-bigmem i386 2.6.32-48squeeze6 [27.6 MB]
Get:3 http://ftp.debian.org/debian/ stable/main firmware-linux-free all 3.2 [20.7 kB]
Fetched 27.7 MB in 20s (1,366 kB/s)
Preconfiguring packages ...
(Reading database ... 18065 files and directories currently installed.)
Preparing to replace linux-base 2.6.32-30 (using .../linux-base_3.5_all.deb) ...
Unpacking replacement linux-base ...
Selecting previously deselected package linux-image-2.6.32-5-686-bigmem.
Unpacking linux-image-2.6.32-5-686-bigmem (from .../linux-image-2.6.32-5-686-bigmem_2.6.32-48squeeze6_i386.deb) ...
Selecting previously deselected package firmware-linux-free.
Unpacking firmware-linux-free (from .../firmware-linux-free_3.2_all.deb) ...
Processing triggers for man-db ...
Setting up linux-base (3.5) ...
Setting up linux-image-2.6.32-5-686-bigmem (2.6.32-48squeeze6) ...
Running depmod.
Running update-initramfs.
update-initramfs: Generating /boot/initrd.img-2.6.32-5-686-bigmem
Examining /etc/kernel/postinst.d.
run-parts: executing /etc/kernel/postinst.d/initramfs-tools 2.6.32-5-686-bigmem /boot/vmlinuz-2.6.32-5-686-bigmem
run-parts: executing /etc/kernel/postinst.d/zz-update-grub 2.6.32-5-686-bigmem /boot/vmlinuz-2.6.32-5-686-bigmem
Generating grub.cfg ...
Found linux image: /boot/vmlinuz-2.6.32-5-686-bigmem
Found initrd image: /boot/initrd.img-2.6.32-5-686-bigmem
Found linux image: /boot/vmlinuz-2.6.32-5-686
Found initrd image: /boot/initrd.img-2.6.32-5-686
done
Setting up firmware-linux-free (3.2) ...
update-initramfs: deferring update (trigger activated)
Processing triggers for initramfs-tools ...
update-initramfs: Generating /boot/initrd.img-2.6.32-5-686-bigmemroot@zen-lb:~# reboot
All right, so did it work?
root@zen-lb:~# dmesg | grep ".*NX.*protection"[ 0.000000] NX (Execute Disable) protection: active
Cool. Let's go on then. Let's do a distro upgrade from Squeeze to Wheezy:
root@zen-lb:~# apt-get dist-upgrade
root@zen-lb:~# rebootIndeed:
root@zen-lb:~# cat /etc/*releasePRETTY_NAME="Debian GNU/Linux 7 (wheezy)"
NAME="Debian GNU/Linux"
VERSION_ID="7"
VERSION="7 (wheezy)"
ID=debian
ANSI_COLOR="1;31"
HOME_URL="http://www.debian.org/"
SUPPORT_URL="http://www.debian.org/support/"
BUG_REPORT_URL="http://bugs.debian.org/"root@zen-lb:~# cat /proc/versionLinux version 3.2.0-4-686-pae (debian-kernel@lists.debian.org) (gcc version 4.6.3 (Debian 4.6.3-14) ) #1 SMP Debian 3.2.60-1+deb7u1
The first thing I'm going to do is tune my filesystem. To be honest, this is just a load balancer so I can afford to lose a few seconds of logs if the power goes down.
root@zen-lb:~# vi /etc/fstabproc /proc proc defaults 0 0
# / was on /dev/sdb3 during installation
UUID=b6016824-536e-43bc-8f1f-fbfd2fab146d / ext4 noatime,nodiratime,nobarrier,nobh,commit=120,data=writeback,journal_async_commit,errors=remount-ro 0 1
# /boot was on /dev/sdb1 during installation
UUID=6d4bd9ca-ba29-4700-b90c-07c614d79f0e /boot ext4 defaults 0 2
# swap was on /dev/sdb2 during installation
UUID=3cb4eb4d-b0ab-4b60-825b-fc0224356580 none swap sw 0 0
/dev/scd0 /media/cdrom0 udf,iso9660 user,noauto 0 0
/dev/fd0 /media/floppy0 auto rw,user,noauto 0 0
Go to single user mode and tune my root filesystem (mine is on /dev/sdb3):
root@zen-lb:~# init 1
root@zen-lb:~# tune2fs -O dir_index /dev/sdb3
root@zen-lb:~# umount -a
root@zen-lb:~# e2fsck -D /dev/sdb3
And now increase the number of open files limit:
root@zen-lb:~# vi /etc/security/limits.conf....
* soft nofile 65536
* hard nofile 65536
# End of file
When regular users log in, they get an open files warning, let's correct it by uncommenting these few lines of code in /etc/profile:
root@zen-lb:~# vi /etc/profile....
#if [ -f /etc/sysctl.conf ]; then
# FILEMAX=`grep "^fs.file-max.*=" /etc/sysctl.conf | awk -F'=' '{printf $2}'`
# if [ "$FILEMAX" != "" ]; then
# ulimit -n $FILEMAX
# fi
#fi
Finally, let's update our repos to correctly receive wheezy updates:
root@zen-lb:~# vi /etc/apt/sources.list#official repository for Debian
deb http://ftp.debian.org/debian wheezy main contrib non-free
deb-src http://ftp.debian.org/debian wheezy main contrib non-free
deb http://ftp.debian.org/debian wheezy-updates main contrib non-free
deb http://http.debian.net/debian wheezy main contrib non-free
deb-src http://http.debian.net/debian wheezy main contrib non-free
deb http://http.debian.net/debian wheezy-updates main contrib non-free
deb-src http://http.debian.net/debian wheezy-updates main contrib non-free
deb http://security.debian.org/ wheezy/updates main contrib non-free
deb-src http://security.debian.org/ wheezy/updates main contrib non-free
#official repository for Zen Load Balancer Updates
deb http://zenloadbalancer.sourceforge.net/apt/x86 v3/
All right, I guess we didn't do that much, but it's enough to call the end of Part 1.
