File sharing requirements of remote users G. Bagliesi INFN - Pisa EP Forum on File Sharing 18/6/2001

Jun 18 th 2001 Ep forum on file sharing – G. Bagliesi Outline Tipical services used by remote users at CERN Tipical services a user wants to use when NOT at CERN Conclusions

Jun 18 th 2001 Ep forum on file sharing – G. Bagliesi Services used by remote users when they are at CERN Login Lxplus and group dedicated linux clusters (telnet, ssh), x-windows File transfer and sharing afs: home directories, transparent software distribution ftp: old but “platform independent” (windows, unix, mac…) Nice, nice 2000 Powerpoint presentations, multimedia, good desktop environment File sharing primarily through windows native protocol + ftp Web publishing Central web services, sometime private servers exist Batch LSF, access to mass storage (EPIO files, objectivity, ntuples, …) Mail Central mail services, filters, forwarding A “remote user” is just a CERN user…

Jun 18 th 2001 Ep forum on file sharing – G. Bagliesi When not at CERN: In principle a remote user wants to access all the services of the previous slide “like when he/she is at CERN”: this is clearly not always possible. There are anyway specific needs for the following items: Software mirroring and development Data transfer Home directory access Authentication and remote login

Jun 18 th 2001 Ep forum on file sharing – G. Bagliesi Software mirroring and development AFS: Almost universally adopted in home-labs sometime slow because of old servers (also inside CERN LAN) For some areas (like the experiment specific software) authentication per- site or per-node could be desirable many experiment specific areas are not under AFS and can be accessed only through ftp/login Mirroring: Each group has his own method to mirror the CERN software A standard procedure for the automatic mirroring of CERN and group software outside the CERN could be very useful! CVS: Nice software management and repository system Remote repository mirror could be desirable Could central CVS server dispatch the updates to remote CVS servers? useful for remote developers that want to have updated version of the software in local CVS servers

Jun 18 th 2001 Ep forum on file sharing – G. Bagliesi Data transfer Not always easy to transfer big files to/from CERN How to improve: Dedicated servers which allow file I/O from outside Dedicated disk space to temporarily store the big files Which protocol? RFIO from outside should be useful Is it technically possible to access CASTOR/HPSS areas from outside ? Is AFS able to manage files of several hundreds of MB ? Important point: CERN intranet LAN is still slow (10 Mb/sec in many buildings) and sometime this is the bottleneck of the transfer

Jun 18 th 2001 Ep forum on file sharing – G. Bagliesi Home directory access There are two areas (and two worlds): Linux-unix: everything under afs Easy to access from outside Windows: Nice 2000 with DFS (Nice 95/NT will disappear quickly, I guess…) As far as I know the CERN DFS area is not visible from outside I think everybody would be quite happy if this two areas will be integrated See all NICE files from linux and vice-versa (not with ftp…) Possibly have a single home-dir (with larger quota obviously!)

Jun 18 th 2001 Ep forum on file sharing – G. Bagliesi Authentication and remote login Secure authentication/login should be strongly encouraged SSH has many nice features like X11 port forwarding A reasonable SSH client should be installed by default also under NICE Authentication should be done only once for all the systems Login and file transfers with no need to type any password when already authenticated “at CERN” It is already like this with AFS NICE, WEB (EDH, BHT…) and MAIL services should work in the same way It could be useful to find a standard way to allow remote (and secure) login under windows. Many tools allow this Pcanywhere, VNC, Netmeeting…

Jun 18 th 2001 Ep forum on file sharing – G. Bagliesi Conclusions File transfer, remote software distribution, remote logins are widely used by all the HomeLabs The access to CERN resources from HomeLabs can/should be improved The latest technologies will maybe help to achieve a better global solution for many of this needs