One of the tasks of the inLab FIB is to offer a centralized and highly available computer storage service for students using the computer labs. The network unit where student data is stored is accessible from any of the operating systems available in the classrooms: Linux, Windows XP and Windows 7, and also remotely from the Student’s Corner. This service must be highly available and capable of accepting intense load levels, in order to support the periods of the four-month period when internships, mass exams and resource-consuming processes are carried out.
To offer this service, a disk or data storage cabinet, EMC VNX5300, has been purchased, which can act both as a NAS and as a SAN. We will focus on NAS functionality and the advantages that this technology can bring.
The EMC VNX5300 cabinet completes the requirements of our system:
- integration with our LDAP server, OpenLDAP.
- integration with our domain controller, samba.
- NFS and CIFS protocols.
- high availablity.
It is made up of the following components:
- disk tray, DAE, consisting of 12 disks of 600Gb each.
- 2 management stations, control station.
- 2 NAS servers, data movers, which are the file servers.
The booth allows you to define an LDAP server to query user UIDs. Since the Samba domain controller is also integrated with OpenLDAP, as a backend of the users, this allows us to share the same directory/folder through NFS and CIFS, having the users registered exclusively in OpenLDAP.
All its components are duplicated: the disks in RAID, two control stations in active/passive mode, and 2 data movers in active/passive mode.
The directory tree containing the user data has been divided into five partitions according to the username. This has been one of the most significant changes compared to the previous configuration and has allowed an improvement in the performance of backups and NAS access.
Another change that has brought about the fact of using the NAS, is the work carried out on the Linux client stations that now have two different spaces, the HOME where the user has all the profile configuration, managed by NFSv4, and the DADES space, managed by CIFS, where the practices, statements, etc. can be saved.
The fact that HOME uses the NFS protocol allows us to work with symbolic links, something that the CIFS of the cabin does not allow us to do.
The architecture of the service is as follows:
