Carnegie Supernova Project Computer Information

 

                                                - DCM, 12-09-03

 

Introduction

 

This document is a brief description of the five computers built from components for the Carnegie Supernova Project (CSP).  This document contains essential information for the maintenance and administration of these computers. All long term users and maintainers of these systems need to understand in detail what is communicated here. Please contact me with any questions (david@ociw.edu).

 

Hardware Description

 

There are five computers named csp1-5. All these computers have RedHat (RH) Linux loaded on their system drives except csp5 which has Windows XP Professional. Computers csp1 and csp2 are data reduction and archival machines, csp3 is for lighter data reduction duties and to serve as a spare computer (or for spare parts),  csp4 is for online data reduction and analysis for the new 40-inch IR camera (“RetroCam”), and csp5 is a user interface computer for the RetroCam instrument. The basic hardware configuration of these computers is as follows:

 

AMD Athlon XP 2600 processor, 1 GB DDR400 RAM, ATI Radeon 9000 128 Mb DVI graphics card, ASUS A7N8X Deluxe MB, 6X USB 2.0 ports, firewire capable, 2X100BT Ethernet ports,  36 GB serial ATA (SATA) 10K RPM system drives, Ultra 133 and Serial ATA (SATA) HD interfaces, 19” LCD DVI flat screen display, Multimode writable DVD drives, 3-button scroll wheel optical mouse

 

In addition to the serial ATA system drives, four of the computers (csp1-csp4) have data disks. Of these, csp1 and csp2, which are designed to be the data reduction “workhorses”, have dual data disk. In the case of csp1 these are a pair of EIDE 250GB 7200 rpm drives, in the case of  csp2 these are a pair of ATA 133 160GB 7200 RPM  drives. The other two computers csp3 and csp4 have single 160 GB data disks. The dual drives on csp1 and csp2 are currently configured so that one is an off-line mirror of the other. This mirroring is currently such that the off-line drive is backed-up up daily at 2 am.

 

Hardware Setup Notes

 

Setting up the computers is simple. First connect the keyboard with its color coded connector. The mouse is connected to any USB port on the back of the computer. There are two Ethernet ports on the computer back panel, but for now use the one at the top of the computers when the cabinet is set in the upright position.

 

The LCD display has three connections to the computer case, two of which are important: The white DVI video cable, and the black USB cable for PnP detection. These connections are fairly obvious (any USB port on the back of the computer case can be selected for the USB connection). The final monitor connection is a color coded audio jack (the monitors have small speakers built in).

 

The computer cases have fan speed controls that should, unless the noise level is deemed too high, be kept at maximum levels. There is a CPU temperature monitor as well. The CPU should be kept in the 30-40 C-degree range. Special attention should be paid to the thermal state of csp1 and csp2 as they have multiple hard drives and can run hot (and may be expanded to have more in the future). If possible these computers should be located in an air conditioned environment.

 

Disk Mirroring

 

To mirror the csp1 and csp2 data disks, it was decided to use the Linux utility rsync as opposed to RAID 1 since this allows recovery from accidental deletions or from file damage caused by programs or processes running incorrectly. Rsync makes an incremental backup of the main data disk to the backup drives which is normally kept off line. This backup function is implemented by a script called rsyncbackup held in /etc/cron.daily. Local administrators should examine and understand the contents of rsyncbackup  as it is critical to the archival data integrity of the project.

 

On csp1 and csp2 the main data disks are mounted on boot-up as volumes /data. The backup disk is not mounted except when rsynbackup is running, when it is mounted as /backupdisk. The backup image of /data is held as /backupdisk/data on the second data disk. One needs to monitor the contents of /backupdisk to make sure that it has a faithful reproduction of /data. To do this, mount it (as superuser) from time to time and examine its contents (see /etc/cron.daily/rsyncbackup for the mount syntax). Critical point: be sure and umount /backupdisk after this check, or better yet reboot the system. Failure to do so may cause rsyncbackup to fail (this problem may be addressed by a more sophisticated version of rsyncbackup in the future)

 

System and Application Software

 

The computers with Linux have had the following astronomy related applications either tested to work, or specifically installed: iraf, ds9, x11iraf package (xgterm, ximtool, etc.), xfig, gv, ggv, pine, xdvi, sextractor, supermongo, xv, latex, aastex, xpdf

 

In particular as a convenience feature  “launcher” icons are available for ximtool and ds9 on the desktop for user accounts cspuser1-4 (see below).

 

User Accounts

 

In addition to the usual root, iraf, and system accounts, several standard normal user accounts have been created. The user names and passwords will be given to the appropriate personal. These accounts have sample iraf and aastex (latex3e) subdirectories.

 

Some Remaining Issues

 

There are a few remaining issues. First, we need to test and document procedures for using the DVD drives as well as to settle on the type of drive media to use (DVD+R, vs. DVD-R, vs. double-sided DVD+/-R, etc.). I will work on this and make suggestions and give specific command examples by early 2004. I will begin experiments with DVD+R media, but I hope that data archives may eventually use double-sided DVD. It may also be desirable to use both bind both the Ethernet interfaces on nodes csp1 and csp2 to one IP address if there is frequent cross traffic of data between them.