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LDAS @ LIGO-Livingston

Key information
Home page
Account sign-up See Requesting an account on the LDG page
Support ldas_admin_llo@ligo.caltech.edu
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This service is available for all @LIGO.ORG registered collaboration members with accounts and access coordinated as part of the LIGO Data Grid.

Login hosts

Hostname Description Memory CPU model # core GPU
ldas-grid.ligo-la.caltech.edu Production submit 64GB 2 x 2.4GHz Xeon E5-2630v3 16
ldas-pcdev1.ligo-la.caltech.edu Large mem/post-processing 128GB 2 x 2.4GHz Xeon E5-2630v3 16
ldas-pcdev2.ligo-la.caltech.edu Large mem/post-processing 512GB 4 x 2.7GHz Xeon E5-4650 32 4 x Tesla K10 + 2 x GTX750
ldas-pcdev4.ligo-la.caltech.edu 16GB 2 x AMD Opteron 2376 8
ldas-pcdev5.ligo-la.caltech.edu 512GB 2 x 2.2GHz Xeon E5-2698v4 40
ldas-pcdev6.ligo-la.caltech.edu 1.5TB 4 x 3.0GHz Xeon Gold 6154 72
detchar.ligo-la.caltech.edu Dedicated DetChar 128GB 2 x 2.4GHz Xeon E5-2630v3 16
dgx1.ligo-la.caltech.edu 512GB 2 x 2.2GHz Xeon E5-2698v4 40 8 x Tesla V100-SXM2-16GB

For details on how to connect to these machines, please see Access to the LIGO Data Grid.

Additional services

Service URL
JupyterLab https://jupyter.ligo-la.caltech.edu
User webspace https://ldas-jobs.ligo-la.caltech.edu/~USER/

Configuring your user environment on LDAS

This page describes the default user environments on LDAS, and how to customise availability and versions of the following software distributions:

Intel oneAPI

The Intel oneAPI Base Toolkit is available by default on LDAS, with the exception of the intelpython and mpi modules.

Disabling all Intel modules

To disable loading of all Intel oneAPI modules, create an empty file in your home directory called ~/.nointel:

touch ~/.nointel

Customising the included oneAPI modules

To take full control over which modules to include/exclude (including pinning specific versions) please create ~/.oneapi_config.txt that takes precedence over the default /opt/intel/oneapi/oneapi_config.txt

MATLAB

Enabling MATLAB

MATLAB is available on the command path by default, and can be discovered using which:

$ which matlab
/ldcg/matlab_r2015a/bin/matlab

Note

The default matlab version will be updated from time-to-time according to approval from the Software Change Control Board.

Enabling a specific version of MATLAB

To select a specific version of MATLAB, create a file in your ${HOME} directory named .usematlab_{release}, where {release} is the release number of MATLAB that you want, e.g:

touch ~/.usematlab_r2019a

Listing available MATLAB releases

To list the available MATLAB releases, just run this:

ls /ldcg/ | grep matlab

Disabling MATLAB

Disabling MATLAB

To opt out of all MATLAB releases, create a file in your ${HOME} directory named .nomatlab:

touch ~/.nomatlab

Warning

~/.nomatlab takes precedence over any ~/.usematlab_* files, so if you want to opt in after previously opting out, make sure and remove the old ~/.nomatlab file.

Restoring accidentally deleted/modified files at CIT

Home directories on the CIT cluster use the ZFS filesystem, which allows for periodic snapshots. This allows you to recover accidentally deleted/modified files as long as the file you want to recover existed when the snapshot was taken.

Here's an example. Let's assume you're a user working in your home directory on the CIT cluster:

$ pwd
/home/albert.einstein/temp
$ ls -l test.file
-rw-------   1 albert.einstein albert.einstein  8416 Feb 18  2020 test.file
$ rm test.file

Oops--you didn't mean to delete test.file!

To find out if you can recover this file, first you need to see what snapshots are available. You can find them by looking at the files in the .zfs/snapshot directory inside your home directory:

$ ls /home/albert.einstein/.zfs/snapshot
autosnap_2021-10-01_00:00:01_monthly/  autosnap_2021-12-07_00:42:36_weekly/  autosnap_2021-12-07_15:25:30_hourly/  autosnap_2021-12-08_05:56:38_hourly/
autosnap_2021-11-01_19:27:51_monthly/  autosnap_2021-12-07_02:43:53_hourly/  autosnap_2021-12-07_16:16:33_hourly/  autosnap_2021-12-08_07:03:20_hourly/
autosnap_2021-11-15_23:30:55_weekly/   autosnap_2021-12-07_03:32:00_hourly/  autosnap_2021-12-07_17:35:32_hourly/  autosnap_2021-12-08_08:34:30_hourly/
autosnap_2021-11-16_16:17:41_monthly/  autosnap_2021-12-07_04:18:34_hourly/  autosnap_2021-12-07_18:42:37_hourly/  autosnap_2021-12-08_09:22:19_hourly/
autosnap_2021-11-16_16:17:41_weekly/   autosnap_2021-12-07_05:33:12_hourly/  autosnap_2021-12-07_19:06:09_hourly/  autosnap_2021-12-08_10:32:40_hourly/
autosnap_2021-11-22_23:48:55_weekly/   autosnap_2021-12-07_06:06:00_hourly/  autosnap_2021-12-07_20:38:54_hourly/  autosnap_2021-12-08_11:52:12_hourly/
autosnap_2021-11-29_23:43:30_weekly/   autosnap_2021-12-07_07:42:33_hourly/  autosnap_2021-12-07_21:05:52_hourly/  autosnap_2021-12-08_13:02:57_hourly/
autosnap_2021-12-01_00:24:05_monthly/  autosnap_2021-12-07_08:07:01_hourly/  autosnap_2021-12-07_22:31:05_hourly/  autosnap_2021-12-08_14:48:35_hourly/
autosnap_2021-12-02_00:17:00_daily/    autosnap_2021-12-07_09:45:35_hourly/  autosnap_2021-12-07_23:47:03_hourly/  autosnap_2021-12-08_16:08:23_hourly/
autosnap_2021-12-03_00:11:47_daily/    autosnap_2021-12-07_10:15:41_hourly/  autosnap_2021-12-08_00:21:21_daily/   autosnap_2021-12-08_17:28:41_hourly/
autosnap_2021-12-04_00:04:44_daily/    autosnap_2021-12-07_11:47:58_hourly/  autosnap_2021-12-08_00:21:21_hourly/  autosnap_2021-12-08_18:28:45_hourly/
autosnap_2021-12-05_00:06:23_daily/    autosnap_2021-12-07_12:25:30_hourly/  autosnap_2021-12-08_02:14:08_hourly/  autosnap_2021-12-08_19:39:26_hourly/
autosnap_2021-12-06_00:12:35_daily/    autosnap_2021-12-07_13:11:19_hourly/  autosnap_2021-12-08_03:54:22_hourly/
autosnap_2021-12-07_00:42:36_daily/    autosnap_2021-12-07_14:44:16_hourly/  autosnap_2021-12-08_04:39:22_hourly/

As you can see, there are snapshots labeled with their time day and time (denoted in yyyy-mm-dd_hh:dd:ss format). To see if a particular file exists in a snapshot, you can just ls the snapshot for it. However, you should note that the <homedir>/.zfs/snapshot/<snapshot> will be the root of that snapshot, i.e. a picture of what <homedir> looked like at the time the snapshot was taken. Therefore, you'll need to look down the path where the file of interest lived (in the example, /temp):

$ ls -l /home/albert.einstein/.zfs/snapshot/autosnap_2021-12-08_11:52:12_hourly/temp/test.file
-rw------- 1 albert.einstein albert.einstein 8416 Feb 18  2020 /home/albert.einstein/.zfs/snapshot/autosnap_2021-12-08_11:52:12_hourly/temp/test.file

You can view/open any of the files in a snapshot just as you would with the original file, so you can check that the file is the version you want. However, please note that the snapshots are read only, so you cannot modify the file inside the snapshot.

Once you've found a version of the file to restore, you simply need to copy it back to your home directory so you can work with it. Simply use cp:

$ cp -ip /home/albert.einstein/.zfs/snapshot/autosnap_2021-12-08_11:52:12_hourly/temp/test.file /home/albert.einstein/temp
$ ls -l test.file
-rw------- 1 albert.einstein albert.einstein 8416 Feb 18  2020 test.file

The -p option will preserve the ownership and timestamps of the file (if that's what you want).

If you want to restore an entire directory tree, this is also possible, just use something like

$ cp -ipr /home/albert.einstein/.zfs/snapshot/autosnap_2021-12-08_11:52:12_hourly/temp /home/albert.einstein

to restore the entire "temp" directory, where the '-r' option is for a recursive copy of the entire tree.