User Tools

Site Tools


This is an old revision of the document!

ALICE beast machine admin info

This page contains information on how to manage the ALICE beast machine.

For a description of the machine hardware and WIP click here

Brief storage view

 system SSD (M.2) 90GB
    /       # system root
    /opt    # folder for user software
    /var    # folder for logs and other runtime things
    /tmp    # temporary folder
 emergency admin user homes SSD (M.2) 90GB
  >>>> There is still time to change these. Please speak up. I could for example allocate more space for system and opt instead of the one allocated for /ahome. <<<<

 user homes SSD (U.2) 690GB
    /home   # user home folders
 data disk (RAID6) 55TB
    /disk   # available for data, filesize >= 1MB 


The machine is only accessible within the hep network as it was for aurora. One must login to teddi first if outside the division. This can be changed but at the cost of some security service always running in the machine, and me monitoring what happens in terms of logins.

Admin rights

Direct access to root user is discouraged. Administrators should use the sudo command to become root.

There is a special user whose home folder is located in /ahome in case the home folders get corrupted, called alicedrift. You are free to create a password for such user and share it among the group. I recommend you do this asap. This is to be used in case of emergency. Store the password in a secure place.

Adding an administrator

To elect a new administrator, it is enough to add them to the wheel unix group.

:!: Fiddling with sudo configuration files is strongly discouraged. :!:

usermod -aG wheel <username>


usermod -aG wheel pflorido

Software planning

I suggest you install system software according to the distribution, using yum.

As for research software, I would recommend you install:

  • For small files that require performance:
    • in the /opt folder (SSD)
    • in a subfolder of /home (SSD U.2)
  • For large/huge files (> 1MB ) such as docker images, create a specific folder inside the /disk folder (RAID)

Software installation

For system/distribution software installation it is recommended to use the yum command and the rpm system. Centos7 is a RedHat based distribution. The commands are pretty much the same as ubuntu. Here I give you a quick reference of most useful commands.

Search for a package

yum search <string>


yum search tmux

Install a package

yum install <packagename>


yum install tmux

Find which package contains a specific file

yum provides */<expression>


yum provides */libboost*

upgrade system packages

yum upgrade

You will be asked to accept the changes.

Emergency procedures


This section describes how to handle some critical situations.

In what follows I will use terminology that I clarify below.

  • RAID: a device managed by a physical RAID controller card.
  • swRAID: a device managed by software RAID, which is a feature of the kernel to create RAID disks. Such feature is less reliable than an actual physical raid but it should give enough time to take action when something breaks. It includes you being able to finish a running job before shutting down the machine.

RAID disk failing

This can happen if one or more of the RAID disks are broken or starting to fail. You are supposed to take action asap.

How to detect?
What to do

Home folder swRAID failing

There are two U.2 disks in software RAID serving user homes. Should one disk fail, the homes will continue to work, but as soon as possible you are required to replace the broken disk to avoid data loss.

This can happen if one of the U.2 disks containing home folders is faulty.

How to detect?
What to do

system swRAID failing

The system M.2 disk is in software raid with two partitions of the U.2 disk. This allows the machine to continue working when the M.2 disk is faulty. However, the machine will not reboot in case this disk breaks. Unfortunately the U.2 disks cannot be used for booting. It is a limitation of the machine.

Nevertheless it's possible to entirely restore the disk image by copying one of the two copies in the U.2 drives. See description below.

How to detect?
What to do


:WIP: The machine will be monitored by a software and system monitor and an hardware monitor. Access and details to these systems will come.

alicebeast.1592495311.txt.gz · Last modified: 2020/06/18 15:48 by florido

Accessibility Statement