Difference between revisions of "Hardware servers"
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Van vrijwel alle schijven die onder beheer van C&CZ staan, worden regelmatig [[
Van vrijwel alle schijven die onder beheer van C&CZ staan, worden regelmatig [[|backups]] gemaakt, zodat bij kleine of grote calamiteiten de data niet verloren gaan.
Almost all disks that are managed by C&CZ, are being [[
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.
Revision as of 17:13, 19 October 2007
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 Core Linux or Windows-XP. There are also workstations in the PC-rooms and studylandscape for general use by anybody with a science-login.
- solost, the Solaris login-servers for students.
- solo and wn5, the Solaris login-servers for employees.
- lilo, 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.
- 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, 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 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 empoyess 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.