Difference between revisions of "Hardware servers"
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C&CZ manages (for departments) workstations with Fedora Linux or Windows-XP. There are also workstations in the PC-rooms and Study
C&CZ manages (for departments) workstations with Fedora Linux or Windows-XP. There are also workstations in the PC-rooms and Study for general use by anybody with a [[Studenten_login|Science login]]. Almost all those machines are dual-boot, the user can choose to boot Fedora Linux or Windows-XP.
Revision as of 21:43, 16 February 2011
Servers and Workstations
C&CZ manages ca. 50 Sun/Solaris/SPARC servers, ca. 120 Linux workstations and ca. 600 servers and workstations with MS-Windows, primarily in the domain science.ru.nl. The hardware and version of the operating system is registered in DNS.
C&CZ manages (for departments) workstations with Fedora Linux or Windows-XP. There are also workstations in the PC-rooms and Study area for general use by anybody with a Science login. Almost all those machines are dual-boot, the user can choose to boot Fedora Linux or Windows-XP.
- lilo and stitch, the Linux login-server for employees and students.
Ways to log into the login servers:
- With SSH (Secure Shell), which is an encrypted connection, so passwords can't be sniffed. An SSH connection is possible from all over the Internet. It is possible to tunnel X11-traffic (from Xwin32).
- With telnet or rsh. Because passwords can in that case be sniffed from the network, this is only allowed from within the RU/UMCN-campus.
The CPU-load of important servers is being monitored.
Beginning 2006, a number of departments bought a bunch of Sun Fire X4100 dual-processor dual-core machines in order to have more Linux computing power. In 2007 Cluster software was installed. Departments have regularly bought new machines that were added to the cluster. As of May 2009, the cluster totalled 280 cores. The CPU-load of the clusternodes is being monitored.
On the Do-It-Yourself website each user can see which mail server will store incoming mail for his account. Mail can be accessed with POP3 and IMAP over SSL. In every domain managed by C&CZ the alias smtp.science.ru.nl points to the machine that accepts mail with the SMTP-protocol. N.B.: If one uses a (non-RU) Internet provider, our mail server will only accept mail for our (RU) mail-addresses. Most other mail will not be accepted ("Relaying Denied!"). One can prevent this by using the smtp-server of the Internet-provider or by using Authenticated SMTP.
The amount of mail and spam is being logged.
The alias printer-srv.science.ru.nl points to the machine that manages almost all queues for the network printers.
The most important disk servers on that server-subnets are pluri, manus, plus en multi. Pluri en manus have home-directories for employees and students, respectively. The RAID-arrays with these home-directories have 7*24 hours support. Therefore a problem with these RAID-arrays should not continue for many hours. The individual disks are scsi-disks with 5 years of factory warranty.
Multi and plus also have RAID-arrays, but these are less expensive (SATA-1 or SATA-2 disks, support only during bussiness hours). Faculty departments can rent disk space on these RAID-arrays, at this moment in chunks of 90GB for 405 euro for 3 years. This is 1.50 euro per GB per year. Although this is much more expensive than buying 1 disk for 1 PC, it makes sense often because of the reliability (redundant disks, backup, support contract) and security (stable server). One or more directories can be shared to Windows-PCs by attaching a network share. Unix/Linux computers can mount the same disk through NFS. Reading and/or writing to such a directory is generally only possible for a specific group of logins.
Almost all disks that are managed by C&CZ, are being backupped regularly, in order to be able to restore data in case of small or large calamities.