This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.
Hi Jeff, I want to thank you for all the help you have provided thus far. I now have our LDM server setup and I think configured. I have a few questions that I hope are OK to ask. Information: - Virtual computer running Red Hat Enterprise 5.7, 1 GB RAM, 20 GB HDD, IP: 146.6.225.29 - LDM 6.9.8 has been installed, queue created and the services started Here are the questions I have, 1. How is security handled to keep unwanted people from access the data or is that an issue? 2. Any security issues I need to be aware of to make sure the server is configured as it should be? 3. How do I confirm LDM auto starts when the server is rebooted? 4. Do all changes have to be made through the ldm or root user? 5. I'm getting a message from SELinux that it is in permissive mode and is allowing things that it would not otherwise block. For LDM to function as it should, what mode should the system default enforcing mode be set to or is permissive advisable? 6. Is there anything special I need to know about the queue before I can hand the server off to the research group to start their configuration? Thank you, Scott Thank you, Scott -----Original Message----- From: Jeff Weber [mailto:address@hidden] Sent: Monday, August 29, 2011 1:35 PM To: Hammock, Scott Subject: Re: FW: LDM Unidata Hi Scott, Ben hit it on the head, it --depends-- on what you are planning on doing :) We suggest that you have enough RAM so that your queue can live in RAM space. Now, depending on how long you desire the data to live in your queue, we can evaluate RAM space. I would encourage to get no less than 2GB of RAM, and suggest 10-15 GB of RAM. Not knowing if CUAHSI wants to archive, or for how long it is desirable to be on disc, the storage volume is even more nebulous. i.e. NEX2 ~3GB/hour, NEX3, ~1GB/hour, obs +sat+grids 1-2GB/hour, so 5-7GB of RAM will allow data to live for about an hour in yuor queue. Here are some volumes: Feed Average Maximum Products (M byte/hour) (M byte/hour) number/hour CONDUIT 3294.127 [ 36.982%] 9209.677 83840.977 NEXRAD2 2867.231 [ 32.190%] 3717.636 62905.341 NEXRAD3 1006.674 [ 11.302%] 1467.467 51560.932 NGRID 797.673 [ 8.955%] 1663.490 16701.545 FNMOC 293.180 [ 3.291%] 1826.717 2539.455 HDS 273.803 [ 3.074%] 502.401 19149.409 NIMAGE 180.327 [ 2.024%] 344.132 205.818 FNEXRAD 97.280 [ 1.092%] 119.409 70.523 IDS|DDPLUS 43.162 [ 0.485%] 55.504 34630.545 UNIWISC 22.092 [ 0.248%] 35.134 25.864 EXP 18.452 [ 0.207%] 232.695 138.614 LIGHTNING 4.690 [ 0.053%] 6.936 347.773 GEM 3.728 [ 0.042%] 30.579 349.114 DIFAX 3.552 [ 0.040%] 12.382 4.932 FSL2 1.368 [ 0.015%] 1.539 22.227 I would guess that CUAHSI will desire all the radars (both level2 and level3) some model output, surface obs(IDS|DDPLUS), maybe sat imagery??? (NIMAGE and/or UNIWISC). PLease let us know if you have any more questions, we are here. Jeff --------------------------------------------------------------------- Jeff Weber address@hidden : Unidata Program Center PH:303-497-8676 : University Corp for Atmospheric Research 3300 Mitchell Ln : http://www.unidata.ucar.edu/staff/jweber Boulder,Co 80307-3000 : --------------------------------------------------------------------- On Sun, 28 Aug 2011, Ben Domenico wrote: > Hi Scott, > > I'm at a conference out of town right now, but I would forward your > note to the experts in any case, Steve Emmerson and Jeff Weber. > > The quick answer to your question about disk space is that it depends > entirely on how much data you wish to capture locally and in what > form. If you were to subscribe to all data from all streams, it amounts to a > couple > GB per hour. I'll let Jeff and Steve follow up with the limits at the > other end, i.e., the minimum configuration. It helps to have lots of > memory since the queue is kept in memory. > > It's great to hear that you are interested again. We tried this a few > years ago at the SDSC CUAHSI site and I don't think anything ever came > of it. > > Good luck and please let me know how it goes. > > -- Ben > > On Fri, Aug 26, 2011 at 7:45 AM, Hammock, Scott <address@hidden>wrote: > > > Hi Ben,**** > > > > ** ** > > > > I provide I/T support for Dr. David Maidment at The University of > > Texas at Austin. He is wanting to get an LDM server setup for the > > research he is doing. Can you direct me to where I can get > > information about what is needed to get an LDM server setup and > > configured? I have the site > > http://www.unidata.ucar.edu/software/ldm/ldm-current/basics/platform > > .html, but it leaves a few questions in my mind. The main question I > > need to get the initial setup of the server is the amount of disk > > space that will be > > required.**** > > > > ** ** > > > > Thank you,**** > > > > Scott Hammock**** > > > > ** ** > > > > Information Technology Coordinator II**** > > > > Information Technology Group - Dean's Staff University of Texas - > > Cockrell School of Engineering > > 1 University Station Stop C2100 > > Austin, TX 78712**** > > > > address@hidden**** > > > > www.engr.utexas.edu/itg**** > > > > ** ** > > > > *From:* Fernando Salas [mailto:address@hidden] > > *Sent:* Friday, August 19, 2011 3:25 PM > > *To:* Hammock, Scott > > *Subject:* Re: LDM Unidata**** > > > > ** ** > > > > Hi Scott,**** > > > > ** ** > > > > I think Ben Dominico at Unidata can point you in the right > > direction. Below is his email:**** > > > > ** ** > > > > address@hidden**** > > > > ** ** > > > > Fernando**** > > > > On Fri, Aug 19, 2011 at 2:53 PM, Hammock, Scott < > > address@hidden> wrote:**** > > > > Hi Fernando,**** > > > > **** > > > > Do you have a contact that would be able to give me the specs on > > what is needed to get the LDM setup and configured?**** > > > > **** > > > > Thank you,**** > > > > Scott**** > > > > **** > > > > > > > > **** > > > > ** ** > > > > -- > > Center for Research in Water Resources Environmental and Water > > Resources Engineering The University of Texas at Austin > > (970) 218-1556**** > > >