Omnius
Omnius is the main server providing services on the calafou internal network (".calafou").
Services
Ideally, a short description of services should be available at http://omnius.calafou (this address is only accessible from the local network, e.g. if you are physically in Calafou or use a VPN to connect to the Calafou network).
apt-cacher-ng
"Cache para tu distro de linux, cuanto mas la uses más rápido bajarás tus paquetes."
You can use apt-cacher-ng to install/upgrade Debian and Ubuntu packages on your computer faster than usual and saving a little bandwidth for the community. It saves to the local disk all the packages people request and if the package is already on the disk then it will serve it. Therefore, if you or somebody else used the package you want to install/upgrade before, then apt-cacher-ng will serve it to you faster and without downloading it again from the Internet. This is most useful in workshops when a group of people wants to install a concrete package at the same time, but it is also good to use it in your everyday life.
How to configure my computer to use the apt-cacher-ng in omnius?
The instructions are here: http://omnius.calafou:3142/
Software setup
Omnius runs the current Debian GNU/Linux stable (codename jessie).
One big change in this Debian version is that systemd is used to manage services.
Hardware setup
How the disks are connected?
Omnius has an old motherboard with no SATA support. The workaround is that there is a RAID controller card installed in a PCI slot. However, the RAID controller card driver is not working in Debian Jessie, so we actually use software RAIDs. The function of the RAID controller card is simply to provide 4 SATA ports where we can connect hard drives.
The only disk that is connected directly to the motherboard through an IDE cable (not SATA) is the operating system disk.
Which disks are connected?
There are many disks in omnius.
- Operating system.
- apt-cacher (proxy for caching Debian packages).
- pxe (network booting for installing Linux on machines that are connected to the local network).
- Alexandria (mainly media files like films and music).
- Alexandria RAID1 (copy).
Where are the disks connected?
The box of omnius has a lot of space for hard disks:
- EMPTY
- EMPTY
- alexandria
- alexandria
- EMPTY
- EMPTY
- EMPTY
- omnius-os
- EMTPY
- EMPTY
- apt-cacher
BIOS problems
Blinking cursor: After the message "Successfully installed BIOS" the screen goes black and there is only a blinking cursor. The solution to this problem is to turn off the "BBS support" option in the RAID controller menu, in the SATA configuration section (enter with Control-A when booting).
Specifications
1GB RAM: omnius has 1GB of RAM. The motherboard has 4 slots which are divided into two banks. Each bank has to have identical amount of RAM. At the moment only the first bank is used and there are two 512MB RAMs (PC2100) installed in them.
2x2.66Ghz CPU: It seems that omnius has 2 Intel(R) Xeon(TM) CPU 2.66GHz CPUs (single core).
(2x)2TB HDD: alexandria has two 2TB HDDs in RAID1, so effectively only one can be used to store useful data.
More details
Power supply: ATX, with at least 4 SATA connectors. The motherboard connector is a 4x2 ping connector. At the moment we don't use more the other cables on the power supply.
NICs: There are two ethernet sockets, one 10/100Mbit and another 1Gbit. The first is turned off in BIOS, the other is used as the primary network interface (e.g. eth0).
Backups
1. RAID1 for alexandria
alexandria is automatically copied to another disk. So if one disk fails, they should still work without interruption.
2. Offsite backup for alexandria
Backup happens every day at 3am using a software called "restic", to hypatia, which is a NAS (Network Attached Storage) far from the hacklab.
