Remote Tape Handling on D0 Challenges

D0 Challenge users can access Mass Storage System (MSS) utilities to write/retrieve data to/from 8mm tapes vaulted in the Feynman Computing Center. The old MSS utility capout is being replaced by mssout. In the future, the needfile utility will be replaced by an FMSS (Fermilab Mass Storage System) tape handling utility.

mssout: Writing data to 8mm tape
needfile: Retrieving data from 8mm tape

(Here's a document describing how to spool your data into a d0user application.)

mssout: Writing data to 8mm tape

Data to be copied to tape must reside in the D0 group area on FMSS. Check out the D0 FMSS page for instructions on how to copy your files to FMSS, or to see what's already there. (Data accessed by the piaf server should be available on FMSS.)

The official mssout user's guide (text).

A quick guide:

	% setup mssout
		set up product mssout
	% mssout file_name
		submit a mssout request
		file_name is the name of a mssout control file
	% mssout -q
		to list mssout jobs

Your mssout control file must contain the following directives. For a complete listing of all directives, link to the user's guide above. With exception of the file names, none of the directives are case sensitive.

mail = user@host: Email address to send report of mssout run. Must occur exactly once. Recommended as the first entry of the control file.
vsn = tape_vsn [ single | double ]: Tape to be written. Must occur exactly once. The optional second argument specifies the 8mm tape density. The default is double (8500) density.
file = file_name: Write the indicated file to the tape. The file must be world readable. The file name must be given as a complete path (starting with "/") within the MSS UniTree system, or in the fmss form (starting with "mss:"). No blanks or wild cards are allowed within the file name.

The control file must not contain any blank lines or spaces. Here is an example:

mail=perkins@fnald0.fnal.gov

vsn=uup002

file=mss:/e740/dzero/d0cha/hirosky/piaf/proj2/qcd_group/os_gap_lnr/ qcd_lnr_os_catd_01.cwn

file=mss:/e740/dzero/d0cha/hirosky/piaf/proj2/qcd_group/os_gap_lnr/ qcd_lnr_os_catd_02.cwn

file=mss:/e740/dzero/d0cha/hirosky/piaf/proj2/qcd_group/os_gap_lnr/ qcd_lnr_os_catd_03.cwn

Click here to see an example report from mssout.

needfile: Retrieving data from 8mm tape:

To retrieve the files stored on tape (including fatmen), you can currently use the needfile commands. However, needfile will eventually be removed from FMSS and replaced by facilities using the tape: area. (Check out the FMSS User's Guide for more info.)

	% setup d0captools



	% needfile
	gives a list of available commands.

Most importantly, to stage a tape for access:

	% needfile -stage -vsn vsn [-tape type -email email_address] [options]

You must specify tape type if you want the retrieved files to retain their filename. The possible tape volume types are:

8MM ...... Volume is an unlabeled 8mm cassette.

8MMA ..... Volume is an 8mm cassette with ANSI labels for each file.

8MMD ..... Volume is an unlabeled 8mm double density cassette.

8MMDA .... Volume is an 8mm double density tape with ANSI labels for each file.

When prestaging is complete, the prestager sends a message to the user at the specified email address. If no email_address is specified, a message is sent by default to the users current process. i.e. 'user@d0cha'

To check on the prestaging process, and to see the files/tape after prestaging:

	% ndflist -i vsn

This command returns a summary of the files found on that tape. Example:

	% ndflist -i on5106
	==================================================
	ON5106    5 files 1052 MB  (prestaging)
	File           size location     filename
	-----------------------------------------
   	  1   223357680 TAPE-caphsm1 ALL_090398_28.X_STA01REU1219_ALL00_NONEX00_5042202
   	  2   223062840 TAPE-caphsm1 ALL_090398_29.X_STA01REU1219_ALL00_NONEX00_5042203
   	  3   223455960 TAPE-caphsm1 ALL_090398_30.X_STA01REU1219_ALL00_NONEX00_5042204
   	  4   217854000 TAPE-caphsm1 ALL_090399_45.X_STA01REU1219_ALL00_NONEX00_5042206
   	  5   214905600 TAPE-caphsm1 ALL_090399_46.X_STA01REU1219_ALL00_NONEX00_5042206

You can also get a list of all the prestaging jobs you have submitted by:

	% ndflist
  or,   % ndflist -i  (for detailed file listings)

To copy a file to disk from tape:

	% needfile -lb name -vsn vsn -file nnn

where,

name == the file name

nnn == the file number (position) on tape

Link back to the D0 UNIX page.

Last updated 28 January 1997

J. Perkins

P. Bhat