how to copy files from dcache system to your local machines?

Now our dcache system support three protocols to access files in dcache:Dcap SRM and GSIFTP protocol.And of them, DCAP is a protocal doesnt need GSI Authentication but the other tow protocols need. GSI authentication means a user should have a valid grid certificate and register his grid certificate to a VO(such as ATLAS vo) to access the resource of grid.By these three protocols,dcache provides three client utilities: dccp ,srmcp and globus-url-copy.

Generally , on our dcache system , dccp can a get an avarage IO performance of 15~17MB/s, while the value for srmcp is around 30MB/s (these results are from our local clients c-x-y ).

user should follow these instructions to copy a file from dcache to their local machine.(dcache client should be installed on their local machine first of all)

None GSI authenticated DCAP

copy the file by *dccp*

root@umt3int03 ~#

/opt/d-cache/dcap/bin/dccp /pnfs/aglt2.org/dq2/csc11/AOD/csc11.005401.SU1_jimmy_susy.atlfast.AOD.v12000604_tid010061/csc11.005401.SU1_jimmy_susy.atlfast.AOD.v12000604_tid010061._00033.pool.root.1 /tmp/csc11.005401.SU1_jimmy_susy.atlfast.AOD.v12000604_tid010061._00033.pool.root.1

372537943 bytes in 20 seconds (18190.33 KB/sec)

root@umt3int03 ~# ll /tmp/csc11.005401.SU1_jimmy_susy.atlfast.AOD.v12000604_tid010061._00033.pool.root.1

-rw-r--r-- 1 root root 372537943 Oct 29 10:11 /tmp/csc11.005401.SU1_jimmy_susy.atlfast.AOD.v12000604_tid010061._00033.pool.root.1

GSI authenticated srmcp and globus-url-copy

1) init user's grid certificate

wuwj@c-1-15 ~$ grid-proxy-init

Your identity: /DC=org/DC=doegrids/OU=People/CN=Benjeman J. Meekhof 175714 Enter GRID pass phrase for this identity:

Creating proxy .................................. Done Your proxy is valid until: Wed Sep  5 03:13:59 2007

2-a) copy the file by *globus-url-copy*

wuwj@c-1-15 ~$

globus-url-copy gsiftp://c-1-16.aglt2.org:2811/pnfs/aglt2.org/dq2/trig0_calib0_csc11/trig0_calib0_csc11.005011.J2_pythia_jetjet.recon.AOD.v12000601_tid006819/trig0_calib0_csc11.005011.J2_pythia_jetjet.recon.AOD.v12000601_tid006819._00133.pool.root.1 file:///$PWD/trig0_calib0_csc11.005011.J2_pythia_jetjet.recon.AOD.v12000601_tid006819._00133.pool.root.1
 

(notice, you can use any pool node instead of c-1-16.aglt2.org )

wuwj@c-1-15 ~$ ll

total 44064
-rw-r--r--  1 wuwj umatlas     5094 Aug 28 14:50 ben_doe_cert.p12
-rw-r--r--  1 wuwj umatlas 45115662 Sep  4 15:16 trig0_calib0_csc11.005011.J2_pythia_jetjet.recon.AOD.v12000601_tid006819._00
133.pool.root.1
 

here is the file.

2-b ) copy a file by *srmcp*.

wuwj@c-1-15 ~$

/opt/d-cache/srm/bin/srmcp  --debug=ture srm://head01.aglt2.org:8443/pnfs/aglt2.org/dq2/trig0_calib0_csc11/trig0_calib0_csc11.005011.J2_pythia_jetjet.recon.AOD.v12000601_tid006819/trig0_calib0_csc11.005011.J2_pythia_jetjet.recon.AOD.v12000601_tid006819._00133.pool.root.1 file:///$PWD/trig0_calib0_csc11.005011.J2_pythia_jetjet.recon.AOD.v12000601_tid006819._00133.pool.root.1-copy-by-srm

wuwj@c-1-15 ~$ ll

total 88123
-rw-r--r--  1 wuwj umatlas     5094 Aug 28 14:50 ben_doe_cert.p12
-rw-r--r--  1 wuwj umatlas 45115662 Sep  4 15:16 trig0_calib0_csc11.005011.J2_pythia_jetjet.recon.AOD.v12000601_tid006819._00
133.pool.root.1
-rw-r--r--  1 wuwj umatlas 45115662 Sep  4 15:25 trig0_calib0_csc11.005011.J2_pythia_jetjet.recon.AOD.v12000601_tid006819._00
133.pool.root.1-copy-by-srm

using this command, tow things should be noticed:

1: the srm server :on our dcache system,we only set an srm server on head01.aglt2.org. so by using srm protocol,you can only specify this host as an srm server to access dcache.

2: the pnfs path. Just as it is mounted to the other machines, it should be /pnfs/aglt2.org/dq2/.... all the data users need to use are in this directory or its subdirectories.

-- WenjingWu - 04 Sep 2007