| protocol | meaning | example |
|---|---|---|
| guid | GUID | guid:3238b240-61f1-11da-8cd6-0800200c9a66 |
| lfn: | logical file name | lfn:dc2.003007.digit.A1_z_ee._00001.aod-1000.pool.root |
| srm | SRM | srm://dcsrm.usatlas.bnl.gov/pnfs/usatlas.bnl.gov/data/prod/rome/datafiles/rome/recov10/rome.003041.recov10.J8_Pt_2240/rome.003041.recov10.J8_Pt_2240._00053.AOD.pool.root.1 |
| gsiftp | globus copy | gsiftp://aftpexp02.bnl.gov/usatlas/magdacache001/common/Rome-AOD/datafiles/rome/recov10/rome.003041.recov10.J8_Pt_2240/rome.003041.recov10.J8_Pt_2240._00040.AOD.pool.root |
| dcap | dCache | dcap:/pnfs/usatlas.bnl.gov/data/prod/rome/datafiles/rome/recov10/rome.003041.recov10.J8_Pt_2240/rome.003041.recov10.J8_Pt_2240._00053.AOD.pool.root.1 |
| rfio | Castor | |
| file | ordinary file | file:/usatlas/magdacache001/common/Rome-AOD/datafiles/rome/recov10/rome.003041.recov10.J8_Pt_2240/rome.003041.recov10.J8_Pt_2240._00040.AOD.pool.root |
get
Get "resolves" a URL, i.e. transforms into another URL
corresponding to a replica of the same file. This may require
consulting a replica catalog, staging the file or copying to
an accessible location. The usual application is to use a
logical name (GUID or LFN) to find a file which can be read by
an application. The algorithm for resolution is described below.
The command line syntax is
>fms get URLwhere URL can be any of the above. The stdout for the command is one line with resolved URL if successful. Otherwise there is no stdout.
The ownership of the file associated with the output URL will sometimes but not always lie with the user. FMS should be modified to clarify this and perhaps provide means to release or delete the file where appropriate.
copy
The copy command also transforms one URL into another but the
new URL is guaranteed to be a copy of the original file that
is owned by the caller.
The syntax is
>fms copy URL file:/somepathand the output is the same as for get.
put
Put copies the file referenced by the input URL to a
storage element and may register it in a replica catalog.
It returns a URL carrying the SE or replica catlog name
for the file.
The syntax is
>fms put URL
DIAL_FMS_PROTOCOLS
This a a comma-separated list of acceptable protocols and is typically
dictated by the application that will consume the file. E.g. for root
or athena applications it might be "file,dcap,rfio".
DIAL_FMS_PROTOCOL_ORDER
This a a comma-separated list of extended protocols in order
of preference. Extende protocols may add a directory path or
can be the special value "copy" meaning to make a copy of
the file. The value for this variable depends on the site
configuaration. For example, the value
file:/atlascache001,dcap:/thissite.org:8443,copy:/tmp/usercache"instructs FMS too first look for an ordinary file in the ATLAS cache directory, then try the indicated dCache sever and finally to copy the file to a tmp directory.
DIAL_FMS_CATALOG
This is a comma-separated list of file replica catalog locations
used to resolve URL's.
These are prefixed by the the DIAL class used to interpret the location.
A suitable value for BNL might be
PoolFileCatalog:mysqlcatalog_mysql://dq2user:wnw@db1.usatlas.bnl.gov:3306/localreplicas,MagdaFileCatalog
DIAL_FMS_SE
This is an extended protocol specifying the storage element. E.g.
gsiftp://mygsiserver/mypath or srm://srmserver/mypath.
DIAL_FMS_SE_CATALOG
This is a prefixed replica catalog location indicating the catalog
that should be used to register files put into the storage element.
DIAL_FMS_VERBOSE
FMS will write debugging messages to stderr if this variable is
set to any nonblank value.
copy
The algorithm for copy is the same except the list of extended protocols
is replaced with the single destination indicated on the command line.
put
For put, the file is copied to the SE (user retains control of the
original). If no SE file catalog is defined, then the SE URL for
the file is returned. If there is an SE file catalog, the SE URL
is registered there and the natural logical URL is returned, guid
for the pool file catalog.