This document provides an overview of the file server infrastructure at NIKHEF. It discusses the various protocols used, including NFS, SMB, and AFS. It describes the different network availability zones and file services for Unix and Windows clients. Backup and archiving is done via TSM tape robot. Home/project directories are served from Ajax and Paling servers, while data directories come from servers like Gandalf. Disk quotas and AFS usage are also outlined. Additional storage capacity will be added soon via 4 new Linux servers with a total of 8 terabytes of storage.

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File server infrastructureFile server infrastructure
@NIKHEF@NIKHEF
CT system support

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OutlineOutline
• Protocols
• Naming scheme (Unix, Windows)
• Backup and archiving
• Server systems
• Disk quota policy
• AFS

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ProtocolsProtocols
• NFS
• Unix platform
• SMB
• Windows (native)
• Unix Open Source implementation (samba)
• AFS
• Unix server/client
• Windows client

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Network availabilityNetwork availability
• hefnet, ikonet
• NFS, SMB, AFS
• pcnet
• SMB, AFS
• guestnet
• SMB, AFS
• internet (world)
• AFS
NOTE:
•Dial-in: access to guestnet.
•Access via cable/ADSL: client limited to AFS

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Unix file service (1)Unix file service (1)
• Automount
• Automatic mount in case of user access
• Automatic unmount after time out (10 min.)
• Automount maps distributed by NIS

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Unix file service (2)Unix file service (2)
• Automount naming scheme:
• Entry in automount map corresponds with top-level directory
• Top-level directories:
• /user user home directories
• /project common directories for projects and groups
(also accessible as /group and /global)
• /public central available software (/usr/public,
/usr/local) and /www
• /data bulk data storage per project/experiment
• /data/week scratch data directory (100 GB)
• Desktop
• /stage/hostname shared data disk
• /localstore non-shared data disk

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Windows file serviceWindows file service
• Global name space:
• palingfred$ convention: map windows user
home directory on H: drive
• palingprojectsmdt common directories for projects/groups
• ajaxprojectdzero idem on Unix file server
• gandalfdatadzero bulk data storage per project or
experiment
Note: Windows clients can access Windows and Unix file servers
Unix clients can only access Unix file servers

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Backup and archive policyBackup and archive policy
• TSM service at SARA
• Tape robot (15 TB available for NWO institutes;
currently 2.5 TB in use by NIKHEF).
• Daily incremental backup (starts at 10:00 PM)
• Home, project and /www directories
• Deleted files are kept 100 days on tape
• Restore on request via helpdesk
• Archiving user files on request via helpdesk
• Archiving ‘do-it-yourself’:
• CD/DVD burner
• DLT tape unit ‘bombur’ in H137a

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Home and project directory serversHome and project directory servers
• Ajax
• Sun Enterprise Server 3500
• Solaris 2.8
• 3 x RAID unit, 1.2 TB bruto
• Paling
• Dell PowerEdge 4400
• Windows NT4
• RAID unit 170 GB bruto

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Data directory serversData directory servers
• Gandalf
• Elonex PC Dual CPU
• Linux Red Hat 7.3
• RAID unit; max. 20 IDE disken (16 present)
• Capacity 1.92 TB bruto (1.65 netto)

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Data directory servers trendsData directory servers trends
• Sharing local data disks discouraged
• Reliability, redundancy, performance
• Less complex dependencies between systems
• TBytes of storage requested by running
experiments (D0, ANTARES and ZEUS)

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Coming soon ….Coming soon ….
• 4 x Linux servers with 2.4 TByte bruto
storage capacity each:
• Extending the home and project directories
• Fulfilling the requests for more central data storage
• Adding storage capacity to grid infrastructure
• Hardware:
• Supermicro SuperServer, dual-Xeon 2.8 GHz
• Infortrend RAID unit, 12x200 GB IDE disks
• Interface: dual port 160 MB/sec UltraSCSI

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Disk quota policyDisk quota policy
• Default quota on home directory:
• 400 MB per user on Unix
• 100 MB per user on Windows
• 15 MB profile space on Windows
• Group quota on data directory:
• Starting at 50 GB per group/project
• Project directories currently limited
by file system size

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AFSAFS
• AFS is a distributed file service protocol
• Aimed for wide-area network
• Available as open source
• Software for Unix and Windows (client only)
• Popular amongst HEP sites (CERN, DESY, etc)
• Naming schema: /afs/cellname/….
• /afs/cern.ch/users/f/fred/…
• /afs/nikhef.nl/user/fred/…

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AFS compared to NFSAFS compared to NFS
• Advantages:
• Central authentication and authorization (Kerberos)
• Local caching of files (in case of low network bandwidth)
• Advanced file access attributes (like ACL’s in Windows,dir.level)
• Disadvantages:
• Local caching of files (in case of high network bandwidth)
• Cannot handle large files (max 2 GB file, max 8 GB volume)
• Complex system administration

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AFS cell at NIKHEFAFS cell at NIKHEF
• Started March 2002
• Limited user group (ZEUS, LHCb)
• Currently 20 user accounts
• Not integrated into existing user admin

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Questions?Questions?