FAQ (frequently asked questions)
- What is the pS-Performance Toolkit and where do the tools come from? The pS-Performance Toolkit ISO image is derived from the standard Knoppix v5.0.1 Live-CD ISO image. Using the re-mastering instructions provided by Knoppix, the kernel was replaced with a Web100-enhanced version (currently Linux 2.6.27.37). Then, performance tools developed by Internet2 staff, Pittsburgh Supercomputer Center (PSC) researchers, and Stanford Linear Accelerator Center (SLAC) researchers were added to the image. More information on the pS-Performance Toolkit is available at: http://psps.perfsonar.net/.
- How do I run the NPAD system? The NPAD (Network Path and Application Diagnosis) is a client/server program developed by the network research group at Pittsburgh Supercomputer Center (PSC). At boot time, the pS-Performance Toolkit starts the NPAD server process and leaves it listening on TCP port 8200. To use this server, a user starts a Java-enabled web browser and points it at the pS-Performance Toolkit server (http://HOST:8200). The server automatically downloads a Java applet to the client. Then the user runs a test to begin the diagnostic process. Once the test has been completed, the server displays a results page on the clients browser. The user may examine these results and follow the recommendations to resolve problems. If the user is unable to repair a reported problem, the results page URL can be emailed to the appropriate system administrator or NOC operator. The server retains a complete record of the test results and the raw data used to derive these results. This allows post-processing of interesting results to determine what went wrong and to improve the reporting capabilities of the NPAD server.
- How do I use the NPAD command line client (diag-client)?
The diag-client is a command line version of the NPAD diagnostic client. Instead of needing a web browser,
this client runs the tests from a terminal window. The basic options are to provide a server name/address
and the connection IP. The NPAD server has two ports open:
- 8200 for HTTP traffic
- 8100 for measurement traffic.
Please connect to 8100:
[knoppix@Knoppix ~]$ diag-client HOSTNAME 8100 Using: rtt 10 ms and rate 20 Connected. Control connection established. port = 8003 Starting test. Parameters based on 107 ms initial RTT peakwin=27617 minpackets=3 maxpackets=83 stepsize=8 Target run length is 608 packets (or a loss rate of 0.16447368%) Test 1a (11 seconds): Coarse Scan Test 1b (11 seconds): ... ...
Connecting to the HTTP port will result in the following error:
[knoppix@Knoppix ~]$ diag-client HOSTNAME 8200 Using: rtt 10 ms and rate 20 Connected. Protocol error: bad handshake. Please make sure you have the latest client, and you have the correct port number
- How do I use BWCTL? BWCTL (Bandwidth Test Controller) is a client/server program developed to simplify Iperf, thrulay, and nuttcp testing between hosts. At boot time, the NPTookit starts a BWCTL server process and leaves it listening on TCP port 4823. This server may then be accessed by remote BWCTL clients. Additionally, the disk contains BWCTL client applications that can be used to test to remote instances. The BWCTL server allows TCP tests with a maximum duration of 60 seconds. To run a test to a remote BWCTL server:
- Logon to the pS-Performance Toolkit server using the knoppix or other valid userid
- Identify the remote server
- Run bwctl -s remote-bwctl-server command to stream data for 10 seconds from the locally instance to the remote BWCTL server. Results are displayed on our console or terminal window.
- How do I run the NDT system? The NDT (Network Diagnostic Tool) is a client/server program developed to simplify testing to desktop/laptop computers. At boot time, the pS-Performance Toolkit starts a pair of NDT server processes and leaves them listening on TCP ports 7123 and 3001. To use this server, a client starts a Java-enabled web browser and points it at the pS-Performance Toolkit server (http://HOST:7123). The server automatically downloads a Java applet to the client. The end-user can run a test to begin the diagnostic process. Once the test has been completed, the server displays a results page on the clients browser. The end-user may examine these results and follow the recommendations to resolve problems. If the end-user is unable to repair a reported problem, the user may click the Report Problems button to generate an email that will be addressed to the appropriate pS-Performance Toolkit administrator. The server retains a record of the test results to allow the post-processing of interesting results to determine what went wrong and to improve the reporting capabilities of the NDT server.
- How do I use the NDT command line client (web100clt)? The web100clt is a command line
version of the NDT diagnostic client. Instead of needing a web browser,
this client runs the tests from a terminal window. The basic options are to provide a server name/address
and the connection IP. The NPAD server has two ports open:
- 7123 for HTTP traffic
- 3001, 3002, 3003 for measurement traffic.
Please connect to 3001, 3002, or 3003:
[knoppix@Knoppix ~]$ web100clt -n HOSTNAME -p 3001 Testing network path for configuration and performance problems -- Using IPv4 address Checking for Middleboxes . . . . . . . . . . . . . . . . . . Done checking for firewalls . . . . . . . . . . . . . . . . . . . Done running 10s outbound test (client to server) . . . . . 164.00 kb/s running 10s inbound test (server to client) . . . . . . 13.40 Mb/s The slowest link in the end-to-end path is a a 622 Mbps OC-12 subnet Information [C2S]: Packet queuing detected: 16.95% (local buffers) Information [S2C]: Packet queuing detected: 67.10% (local buffers) Server '128.193.128.237' is not behind a firewall. [Connection to the ephemeral port was successful] Client is not behind a firewall. [Connection to the ephemeral port was successful] Packet size is preserved End-to-End Server IP addresses are preserved End-to-End Client IP addresses are preserved End-to-End
Connecting to the HTTP port (or other ports) will result in the following error:[knoppix@Knoppix ~]$ web100clt -n HOSTNAME -p 7123 Testing network path for configuration and performance problems -- Using IPv4 address Information: The server 'HOSTNAME' does not support this command line client
- What is NTP? NTP (Network Time Protocol) is a program that synchronizes a computers clock to a global time source. An accurate clock is essential for running many of the measurement tests including BWCTL and OWAMP. The NTP daemon must connect to several, at least four (4), remote time servers to obtain accurately set the local clock. By default the pS-Performance Toolkit server will synchronize to both Internet2 and public time sources. See Step 7 - NTP for information regarding changing the default time sources.
- How do I use OWAMP? OWAMP (One-Way Ping) is a client server program that was developed to provide delay and jitter measurements between two target computers. At boot time, the pS-Performance Toolkit starts an OWAMP server process and leaves it listening on TCP port 861. This server may then be used by remote clients. Additionally, the disk contains OWAMP client applications that can be used to test to remote instances (including a Java client and a console based application). By default, the OWAMP server sends a low-level data stream in each direction and measures the one-way delay and jitter between the two hosts. Separate measurements, one for each direction, are reported to the user at the end of the test. To run a test to a remote OWAMP server:
- Logon to the pS-Performance Toolkit server using the knoppix or other valid userid.
- Identify the remote server.
- Run the owping remote-owamp-server command to make a pair of 10 second delay measurements (one in each direction) between remote OWAMP server and the local instance. Results are displayed on the console or terminal window.
- Where can I ask questions or report bugs?
- For questions, email to performance-node-users at internet2 dot edu. You may also join the mailing list by visiting https://mail.internet2.edu/wws/subrequest/performance-node-users
- For bugs, report at http://code.google.com/p/perfsonar-ps/issues/list . Label the bug as Component-NPToolkit, or state in the bug description the issue involves the pS-Performance Toolkit.
- I get an error similar to DBD::mysql::db selectrow_array failed: Table 'pingerMA.data_XXXXXX' doesn't exist at /some/path/to/Base.pm line XXX. What should I do? Ignore this. Depending on OS scheduling, PingER might try to use a table before creation. It should only happen occasionally.
- Can I Use a Firewall?
The pSPT development team recommends not limiting measurement tools to certain ports; this action may cause
unexpected or unpredictable behavior. Ti enable a firewall anyway, first add all the desired rules to the
firewall then run the command "/etc/init.d/iptables save". The firewall should then automatically come up
on the next boot. Note that there are some caveats to enabling a firewall, namely the amount of holes that
must exist for the measurement tools included on the disk:
- SNMP MA
- open port tcp/8065
- PingER
- open port tcp/8075
- perfSONAR-BUOY
- open port tcp/8085
- open port tcp/8569
- open port tcp/8570
- Lookup Service
- open port tcp/8095
- BWCTL
- open port tcp/4823
- Edit /usr/local/etc/bwctld.conf, set peer_port to a value, open the tcp port for that value
- Edit /usr/local/etc/bwctld.conf, set iperf_port, thrulay_port and nuttcp_port to a specific range, and open the tcp/udp ports for those ranges.
- OWAMP
- open port tcp/861
- Edit /usr/local/etc/owampd.conf, set testports to range, open the udp ports for that range
- NDT
- open port tcp/3001
- open port tcp/3002
- open port tcp/3003
- open port tcp/7123
- NPAD
- open port tcp/8100
- open port tcp/8200
- Apache HTTP Server
- open port tcp/80
- open port tcp/443
- SSH
- open port tcp/22
- NTP
- open port udp/123
- SNMP MA
- How many ports will BWCTL need to operate effectively behind a firewall? The pSPT
development team recommends not limiting measurement tools to certain ports; this action may cause
unexpected or unpredictable behavior. For instance tools such as BWCTL have two factors to consider if the
ports are limited to a small subset:
- Ports available for the regular testing infrastructure on the machine
- Ports available for others to test to the machine
Both situations are controlled by setting values in the same configuration file on the local machine, and it can be hard to predict how many to allow. Some simple calculations can be used to determine a baseline number of ports for the first situation and are based on the parameters of the BWCTL test. Consider the following BWCTL parameters:
- 10 Second long BWCTL tests
- Maximum availability of 6 slots per minute
This would imply needing a total of 6 ports open. To allow for time range rounding errors we should increase this to 7 to be safe. Ideally this would work well, but there are complications due to the nature of the Linux kernel. A general behavior of the kernel is to not release a port from a previous use for up to a minute after it may be closed. This environmental consideration therefore has an impact on the above calculation. Instead of only allowing 7 ports, we should double this number to 14 to be completely safe. - Where can the BWCTL port values be adjusted? The pSPT development team recommends not
limiting measurement tools to certain ports; this action may cause
unexpected or unpredictable behavior. If selecting a port range is still required, BWCTL has several
settings defined in the bwctld.conf file that dictate which ports it may use for testing. The configuration
options are:
- iperf_port - Port range (e.g. 5001-5020) to run the iperf receiver.
- nuttcp_port - Port range (e.g. 5021-5040) to run the nuttcp receiver.
- thrulay_port - Port range (e.g. 5041-5060) to run the thurlay receiver.
- peer_port - Port range (e.g. 5061-5080) to run the server processes of the above tests.
Note that the above ranges are examples, and that calculating the appropriate number of ports based on the FAQ item above is recommended. - Can the OWAMP test port ranges be added via the GUI? The pSPT development team recommends not limiting measurement tools to certain ports; this action may cause unexpected or unpredictable behavior. If selecting a port range is still required, please see this section for instructions on how to alter the testing port range.
- I'd like to PXE boot the pS-Performance Toolkit. Is that possible? Not currently, but this is a consideration of future releases.
- When I boot, it gives me the following error Can't find knoppix file system, sorry. Dropping you to a very limited shell .... This can be attributed to a bad CD burn or a bad ISO image. Check the MD5 sum of the ISO and match this to the posted MD5 value.
- What should I enter for the Communities of interest configuration question? This question can be confusing to answer for new users. The goal is to associate some loosely coupled labels to the data that the pS-Performance Toolkit disk will be making available to the larger world. Think of this step similar to assigning labels to photos or music. Some examples of valid answers are:
- Internet2 - The data made available somehow connects the Internet2 backbone
- LHC (CMS, ATLAS, etc.) - The disk is part of the LHC deployment structure
- eVLBI - The disk is a part of the larger telescope community
- MAX - A connector of member of the MAX gigapop
- DOE-SC-LAB - US Department of Energy Office of Science Labs
Use as many community names as necessary to properly categorize the data from the installation.
- Does my machine have to meet the System Requirements? There is nothing on the pSPT that will prevent systems that do not meet the requirements from starting. Erroneous or inaccurate behavior is possible if the hardware cannot support the measurement tools.
- The colors on my Console Configuration do not match what I see on the web. Some are green already. If you are upgrading from a previous version of the pSPT, the colors may be green already because a particular aspect was configured previously. These do not need to be configured again.
- The Services On This Nodescreen shows many services in the non-running state when first started, what is wrong? Many of the services will be in this state because they are missing some key configuration items (e.g. from the Administrative Info). After following the configuration steps check this screen again, most should be functional.
- The Services
On This Nodescreen doesn't have any IP addresses or hostnames for the
services. Some of the services are Not Running. What is wrong?
- If the pSPT cannot grab a DHCP lease or it is not statically configured, there will be no access to the internet. Many of the services rely on knowing this information, and will therefore refuse to start unil this is corrected.
- Example of a running service with a hostname:
- Example of a running service, but without a hostname or ip address:
- To check to be sure your installation has this information, check the
/usr/local/etc/default_accesspointfile:-
[knoppix@Knoppix ~]$ cat /usr/local/etc/default_accesspoint external_address=lab253.internet2.edu default_accesspoint=lab253.internet2.edu default_ipv4_address=lab253.internet2.edu default_ipv6_address=
-
- I do not see my service in the Global Set Of Services, where is it? Much like DNS, the information that will populate the Global Lookup Service will take time to propagate. Please allow some time (e.g. a few hours) before your service will be fully visible.
- When looking at the data display for perfAdmin BWCTL/perfAdmin OWAMP I do not see results, but I filled out information in the Scheduled Testing area. Where is my data? Data may take several minutes to show up in this area, possible causes: A Test has not run yet (e.g. a 4 hour testing interval may not produce tests for 4 hours. The testing data may not be available in the database yet. A test may complete, but may take several minutes to be stored in the database, and therefore become available to the GUI
- I do not think I am a member of a community, should I put anything? Communities are not required, but they allow other individuals and organizations to find and use your services. It is a good practice to join as many as you may think are applicable.
- What is the purpose of BWCTL Limits/OWAMP Limits? These allow you to limit the influence that outside users have on your system performance. For example, to prevent your machine/network from being saturated with BWCTL tests, limit the duration and maximum bandwidth available. These screens allow a fine grained way to protect resources.
- How can I set limits to prevent others from overusing BWCTL/OWAMP? BWCTL and OWAMP have configurable dialog that allows the administrator to limit the resources consumed. To set the limits for BWCTL, consult this section. To set the limits for OWAMP, consult this section.
- How many NTP servers do I need, can I select them all? It is recommended that 4 to 5 close and active servers be used. The Select Closest Servers button will help with this decision. Note that some servers may not be available due to routing (e.g. non-R&E networks vs R&E networks - a common problem for Internet2 and ESnet servers).
- When clicking on GUI links the following error is seen:
Software error: Cannot write to '/var/log/perfSONAR/Web_Admin.log': No space left on device at /usr/local/share/perl/5.8.8/Log/Dispatch/File.pm line 134. For help, please send mail to the webmaster (webmaster@localhost), giving this error message and the time and date of the error.
The Disk may be full. Try the following command to confirm:
[knoppix@lab246 ~]$ df -h Filesystem Size Used Avail Use% Mounted on tmpfs 1009M 0 1009M 0% /UNIONFS/lib/init/rw udev 10M 64K 10M 1% /dev tmpfs 1009M 0 1009M 0% /dev/shm rootfs 3.4M 23K 3.4M 1% / /dev/hda 587M 587M 0 100% /cdrom /dev/cloop 1.6G 1.6G 0 100% /KNOPPIX /ramdisk 404M 65M 339M 17% /ramdisk /UNIONFS 248M 11M 226M 5% /UNIONFS /dev/shm 1009M 0 1009M 0% /dev/shm /dev/mapper/VolGroup00-LogVol00 145G 97G 42G 70% /mnt/store /mnt/store/NPTools/scratch 248M 11M 226M 5% /scratchThe important mount point is /mnt/store, it this has reached 100%, the drive is full. There are several things that can be done to make room on the disk:
- Try removing unnecessary log files from /usr/local/web/root/admin/log first
- Check to be logrotate is working:
- sudo logrotate -dv /etc/logrotate.conf
- This has been known to fail:
- reading config file ulogd
- error: error accessing /var/log/ulog: No such file or directory
- error: ulogd:1 glob failed for /var/log/ulog/*.log
- If this occurs, try these steps:
- sudo mkdir -p /var/log/ulog
- sudo logrotate -dv /etc/logrotate.conf
- remove older logs from the directories in /var/log
- PingER displays several sets of duplicate results via the GUI, some of which have No
Data. PingER stores the results of all tests ever performed. To clean out the pinger test sets run
the following command:
sudo /usr/local/bin/reset_pinger.sh
- The Sun Java environment was on previous versions of the pSPT, has it been removed?
Java (e.g. the JRE, JDK, and associated browser plugins) have been removed from the pSPT due to license
concerns. Instructions for installing the Java JRE and Plugin (for web browsers on the pSPT):
[knoppix@Knoppix ~]$ sudo apt-get install sun-java5-jre sun-java5-plugin The following will appear, noting that other items may need to be installed: Reading package lists... Done Building dependency tree... Done The following extra packages will be installed: sun-java5-bin Suggested packages: libnss-mdns sun-java5-fonts ttf-baekmuk ttf-unfonts ttf-unfonts-core ttf-kochi-gothic ttf-sazanami-gothic ttf-kochi-mincho ttf-sazanami-mincho ttf-arphic-uming The following NEW packages will be installed: sun-java5-bin sun-java5-jre sun-java5-plugin 0 upgraded, 3 newly installed, 0 to remove and 0 not upgraded. Need to get 29.9MB of archives. After unpacking 82.8MB of additional disk space will be used. Do you want to continue [Y/n]?
After saying yes, the packages will download:
Get:1 http://http.us.debian.org etch/non-free sun-java5-bin 1.5.0-14-1etch1 [22.4MB] Get:2 http://http.us.debian.org etch/non-free sun-java5-jre 1.5.0-14-1etch1 [7465kB] Get:3 http://http.us.debian.org etch/non-free sun-java5-plugin 1.5.0-14-1etch1 [1684B] Fetched 29.9MB in 1m27s (340kB/s) Preconfiguring packages ... Selecting previously deselected package sun-java5-bin. (Reading database ... 68831 files and directories currently installed.) Unpacking sun-java5-bin (from .../sun-java5-bin_1.5.0-14-1etch1_i386.deb) ...
A license agreement will appear, you may choose to either agree to this or disagree. Disagreement will halt installation. After agreeing the installation will proceed. More information is available here. - The SNMP Measurement Archive service is listed as Not Running on the web interface. Is this
normal? The SNMP Measurement Archive is directly tied to the Cacti
configuration. If you have not configured Cacti to monitor a network device, the SNMP Measurement
Archive will not start and show up in this state. The following message will appear in
/var/log/perfSONAR/SNMP.log to indicate the service cannot be started:
2010/01/27 12:17:13 (24778) FATAL> SNMP.pm:370 perfSONAR_PS::Services::MA::SNMP::init - Cacti database is empty, stopping service.
If you have configured Cacti and wish to restart the SNMP MA, try this:
[knoppix@Knoppix ~]$ sudo /etc/init.d/snmpMA.sh restart /etc/init.d/snmpMA.sh stop: SNMP MA (no pid file) not running waiting... /usr/local/perfSONAR-PS/perfSONAR_PS-SNMPMA/bin/daemon.pl --config /usr/local/etc/perfSONAR/SNMP_MA.conf --logger=/usr/local/etc/perfSONAR/SNMP_MA_logger.conf --piddir=/var/run --pidfile=SNMP_MA.pid --user=perfsonar --group=perfsonar /etc/init.d/snmpMA.sh start: SNMP MA started
- Service X is listed as Not Runnning on the web interface. How can I restart?
- Bandwidth Test Controller (BWCTL):
- sudo /etc/init.d/bwctld.sh restart
- Lookup Service:
- sudo /etc/init.d/hLS.sh restart
- Network Diagnostic Tester (NDT):
- sudo /etc/init.d/ndt restart
- Network Path and Application Diagnosis (NPAD):
- sudo /etc/init.d/npad restart
- One-Way Ping Service (OWAMP):
- sudo /etc/init.d/owampd.sh restart
- perfSONAR-BUOY Regular Testing (Throughput):
- sudo /etc/init.d/pSB_collector.sh restart
- sudo /etc/init.d/pSB_master.sh restart
- perfSONAR-BUOY Measurement Archive:
- sudo /etc/init.d/pSB.sh restart
- perfSONAR-BUOY Regular Testing (One-Way Latency):
- sudo /etc/init.d/pSB_owp_collector.sh restart
- sudo /etc/init.d/pSB_owp_master.sh restart
- PingER Measurement Archive and Regular Tester:
- sudo /etc/init.d/PingER.sh restart
- SNMP Measurement Archive:
- sudo /etc/init.d/snmpMA.sh restart
- I can't restart the perfSONAR-BUOY Measurement Archive, the following error appears:
[knoppix@Knoppix knoppix]# sudo /etc/init.d/pSB.sh restart /etc/init.d/pSB.sh stop: pSB (pid 2975?) not running waiting... /usr/local/perfSONAR-PS/perfSONAR_PS-perfSONARBUOY/bin/daemon.pl --config /usr/local/etc/perfSONAR/pSB_MA.conf --logger=/usr/local/etc/perfSONAR/pSB_MA_logger.conf --piddir=/var/run --pidfile=pSB_MA.pid --user=perfsonar --group=perfsonar DBD::mysql::st execute failed: Table './owamp/20100123_DATA' is marked as crashed and should be repaired at /UNIONFS/usr/local/perfSONAR-PS/perfSONAR_PS-perfSONARBUOY/bin/../lib/perfSONAR_PS/DB/SQL.pm line 200. /etc/init.d/pSB.sh start: pSB could not be started
This is a database error and the MySQL database will need to be repaired. To repair the database take the following steps (replacing the database name):
[knoppix@Knoppix knoppix]# sudo su - [root@Knoppix knoppix]# myisamchk -er /var/lib/mysql/owamp/20100123_DATA.MYI - recovering (with sort) MyISAM-table '/var/lib/mysql/owamp/20100123_DATA.MYI' Data records: 979 - Fixing index 1 - Fixing index 2 - Fixing index 3 - Fixing index 4 [root@Knoppix knoppix]# /etc/init.d/pSB.sh restart /etc/init.d/pSB.sh stop: pSB (pid 2975 5185?) not running waiting... /usr/local/perfSONAR-PS/perfSONAR_PS-perfSONARBUOY/bin/daemon.pl --config /usr/local/etc/perfSONAR/pSB_MA.conf --logger=/usr/local/etc/perfSONAR/pSB_MA_logger.conf --piddir=/var/run --pidfile=pSB_MA.pid --user=perfsonar --group=perfsonar /etc/init.d/pSB.sh start: pSB started
- There is an old version of the Linux kernel on the pSPT. Why was the 2.6.27 Linux kernel chosen instead of the latest kernel release series? The pSPT development team is using this kernel because it has been dubbed the long term supported (LTS) kernel. See this for details. This particular kernel lineage will still receive all of the benefits from kernel development (device drivers, security patches) but will not be subject to the same bleeding edge development that the newer (and frequently forked) head of the development effort will receive. This choice makes for a stable kernel that should be free of any defects introduced by new development.
- CRITICAL SECURITY VULNERABILITY XYZ123 was announced hours ago and I am scared the pSPT will be
compromised. When can the users expect a fix? What support guarantees will be offered? Software of
all types, weather it be an operating system or a performance measurement tool may have bugs. Some bugs may
be exploitable and can ruin a single system, and potentially the surrounding network and users. The pSPT
development team is aware of these concerns from the community regarding the security and maintainability
of the pSPT. As such we offer the following points to address these concerns:
- The pSPT development team is a small open source project, and devotes as many resources as possible to addressing flaws in the software.
- The pSPT development team is subscribed to several security oriented mailing lists including those dealing with debian, knoppix, and the linux kernel development effort. When problems are seen, we will alert our users via the pSPT mailing lists.
- We will make every effort possible to address problems in a timely manner using one of the following
methods. Response time will be based on bug severity - critical or exploitable bugs will be given
priority:
- Patches available for currently released pSPT versions after identification and upstream fixes become available
- New releases of the pSPT, normally available quarterly (estimated 3 - 4 disk releases per year)
- All open source software in this product comes with a LICENSE; within each license are the terms of support. With BSD and GPL license the terms are usually use this software at your own risk.
- The pSPT development team cannot offer any form of SLA or hard time frame guarantees.
- NTPD has exited/is not running on my machine, why did this happen and how can I fix
it? NTPD may exit if the hardware clock on the host is too far off from the true time to make a
difference. To skip the clock ahead to the correct time, try these commands:
[knoppix@Knoppix init.d]$ sudo /etc/init.d/ntp stop Stopping NTP server: ntpd. [knoppix@Knoppix init.d]$ sudo ntpdate owamp.newy.net.internet2.edu owamp.wash.net.internet2.edu Looking for host owamp.newy.net.internet2.edu and service ntp host found : eth-0.nms-rlat.newy32aoa.net.internet2.edu Looking for host owamp.wash.net.internet2.edu and service ntp host found : eth-1.nms-rlat.wash.net.internet2.edu 27 Jan 13:42:51 ntpdate[14891]: adjust time server 2001:468:9:12::16:34 offset -0.001660 sec [knoppix@Knoppix init.d]$ sudo /etc/init.d/ntp restart Stopping NTP server: ntpd. Starting NTP server: ntpd.
If NTPD continues to exit on a periodic basis, there may be a hardware failure. Consult the machine's BIOS to see if there may be problems with the hardware clock or internal battery. - What are the hardware requirements for running the pSPT? See this. Note that the pSPT development team has not created hard minimum or maximum requirements - the pSPT will function on almost any form of hardware. Performance considerations do favor meeting or exceeding the minimum guidelines.
- What is the recommended configuration for the hard disk of a machine running the pSPT? There is only one requirement for partitioning the hard disk of a pSPT system: an ext3 partition must be available for storage. The user may configure as many partitions as they need for the pSPT disk, but for simplicity it is recommended that the entire disk be used in a single partition to allow for maximum storage resources. See also this section for hints on storage configuration.
- When using Konqueror on the pSPT, I get the following error:
Username is set to "undefined"
What should I do?
Avoid using Konqueror, if you are using the XWindows system on the pSPT, use Iceweasel or a browser on an external system. - Is it possible to boot the pSPT from a USB Key? Yes, Instructions are available here.
- How do I interpret the Latency/OWAMP Graphs?
The following is a picture of this graph, it is termed an Annotated Time
Line:
- The graph is split into three major parts:
- There are 4 plotted lines on the top portion of the graph:
- Maximum observed latency in the Source to Destination direction
- Minimum observed latency in the Source to Destination direction
- Maximum observed latency in the Destination to Source direction
- Minimum observed latency in the Destination to Source direction
- There are also annotations (labels on the graph) to mark the
following events on the right hand side (if applicable):
- Loss of packets in either direction
- Duplication of packets in either direction
- The bottom of the graph is a sliding window that is used to narrow
or expand the resolution of the data in the top window:
- The sides of the window can be moved
- The entire window can be slid
- The squiggly blue line is an interpretation of the above data. Observation has show that this relates to the Max value for the Destination to Source direction. This choice is due to how the graphs are plotted on the backend. In practice the slope of this line is all that matters.
- There are 4 plotted lines on the top portion of the graph:
- Some notes on interpreting the data:
- The minimum is interpreted as the shortest time it takes for any of the packets in the latency measurement (normally 10pps over the soan of a minute) to arrive.
- The maximum is interpreted as the longest time it takes for any of the packets in the latency measurement (normally 10pps over the soan of a minute) to arrive. This can sometimes cause spikes to form on the graphs that offer a false sense the true latency.
- The graph is split into three major parts:
