Center for Computational Molecular Science and Technology Georgia Institute of Technology Center for Computational Molecular Science and Technology School of Chemistry and Biochemistry

CCMST Weekly News, October 7 2011

October 8, 2011 12:06 am EDT

1. Announcements
2. Statistics
3. Tip of the Week

 

ANNOUNCEMENTS

School Colloquium

October 13, 2011 4:00 PM – 5:00 PM
MoSE G011
Prof. Jason Gestwicki, University of Michigan
Strategies for Targeting Protein-Protein Interactions in the Heat Shock Protein 70 (Hsp70) Complex

STATISTICS

GGATE

Uptime: 111 days
/home directory usage: 44% (6.2 TB available)
/backups directory usage: 95%

Utilization for period from: 09/06/2011 to: 10/06/2011

Note: Full statistics for ggate are available online at: http://ggate.chemistry.gatech.edu:8080 (the link works only for the Gatech Chemistry network)

FGATE

Uptime: 75 days
/home directory usage: 80% (1.2 TB available)
/backups directory usage: 87%

LSF usage for Week 39 (9/26-10/2) (times are in minutes)
GroupJobsTotal CPUAvg CPUAvg WaitAvg Trnr.
Bredas 40 17051 1% 426 0 703
Sherrill 83 227792 12% 2744 5790 11031
Total 123 244843 13% 1991 3907 7673

Note: percentages refer to the total CPU time available for the period.

Most productive user of the Week: loriab 227792.

LSF usage for Month of September (times are in minutes)
GroupJobsTotal CPUAvg CPUAvg WaitAvg Trnr.
Bredas 453 336292 4% 742 233 1177
Hernandez 8 377 0% 47 1880 13202
Sherrill 11242 2392366 29% 213 876 1121
Other 15 34238 0% 2283 1 2306
Total 11718 2763271 33% 236 851 1133

Note: percentages refer to the total CPU time available for the period.

EGATE

Uptime: 16 days
/theoryfs/common directory usage: 44% (372 GB available)
/theoryfs/ccmst directory usage: 96% (40 GB available)

LSF usage for Week 39 (9/26-10/2) (times are in minutes)
GroupJobsTotal CPUAvg CPUAvg WaitAvg Trnr.
Hernandez 11 180153 12% 16378 70343 132956
Total 11 180153 12% 16378 70343 132956

Note: percentages refer to the total CPU time available for the period.

Most productive user of the Week: galen 180153.

LSF usage for Month of September (times are in minutes)
GroupJobsTotal CPUAvg CPUAvg WaitAvg Trnr.
Bredas 16 0 0% 0 0 0
Hernandez 253 158173 2% 625 1947 3142
Sherrill 645 180969 3% 281 41 327
Other 118 232445 4% 1970 0 2006
Total 1032 571587 9% 554 503 1204

Note: percentages refer to the total CPU time available for the period.

TIP OF THE WEEK

By Massimo

Passwordless Login Using ssh-agent

When generating SSH key pairs (using the command ssh-keygen) it is possible to specify an empty passphrase. This is a convenient way of enabling a passworless login from a local to a remote computer, but on the other hand is quite insecure, as it can be exploited by an intruder to effortlessly gain access to the remote computer if the local account is compromised. Thus it is a good practice to protect the SSH key with a passphrase, but this has the inconvenience of having to type the passphrase any time we want to login or transfer files with the remote computer.

A convenient way of solving this problem is to use the utility ssh-agent, that allows to load an ssh identity at the beginning of a session and then use the same identity without having to retype the passphrase. Here is a quick tutorial:

  • Create a key pair using ssh-keygen. Use a strong passphrase to protect the key.
  • Copy the public key to the remote machine. This can be done with the utility ssh-copyid or manually by copying the public key (for instance id_dsa.pub, located in the .ssh directory) to the remote computer and adding it to the file authorized_keys (inside the .ssh directory of the  remote host)
  • Now try ssh remote.host. You should be prompted for the passphrase to unlock the key, but should be able to login to the remote host without using the remote account password.
  • At this point we are ready to use ssh-agent. On the local machine, start a ssh-agent session:
    ssh-agent bash
    
    in this case we just started an interactive shell.
  • Now we load the identity:
    ssh-add
    
    This will load the default key, id_dsa. Use the -i option to load a different key. You will be prompted for the passphrase for unlocking key.
  • Now, as long a we remain inside the ssh-agent session, we can login and transfer files with the remote host without having to type the passphrase again.

 

Do you have usage tips that you want to share with the other CCMST users? Please send them to Massimo (massimo.malagoli@chemistry.gatech.edu) for inclusion in the Tip of the Week section.