NT Cluster & MS Dfs

1. NT Cluster & MS Dfs Gunter Trowitzsch&DESY WindowsNT Group HEPNT - Windows NT Days

2. Server Configuration • Unique OS software configuration for all servers: • WNT 4.0 and Service Pack 3 • Modular hardware configurations for most of all servers • DEC Prioris base system • 200 MHz Pentium Pro • 128 MB memory • External SCSI disk systems2 mirrored hot swappable system disks • Fast Ethernet • PDC, Dfs Server, Mail Server, Cluster Nodes, BDC Zeuthen • BDC Hamburg : PC, 133 MHz Pentium II, 64 MB memory • WINS HH & ZN : PC, 90 MHz Pentium, 32 MB memory • Fileserver Zeuthen : Alpha, 266 MHz, 128 MB memory HEPNT - Windows NT Days

3. Print Server • Inside DESYNT the print jobs are spooled over the NT print server to the central UNIX print server. • At the moment the print server is a PC with a 166 MHz Pentium and 128 MB memory. • some smaller problems - availability and scaling • Test of Microsoft Cluster • successful • fail-over workstiming problems: server failure  starting a print job • To improve the situation we will upgrade to Microsoft Cluster with two nodes. • still a weak point - no job control over the whole process HEPNT - Windows NT Days

4. Home Directory Cluster • Digital WNT cluster • DEC Prioris MX6200, 200 MHz Pentium Pro • 256 MB memory • 2 shared differential SCSI buses • 2 DEC RA310 RAID array with2 RAID 5 sets • 110 GByte disk space RA310 MX6200 256MB MX6200 256MB HEPNT - Windows NT Days

5. NetInstall Application Cluster • Digital WNT Cluster • Digital Server 3000, 266 MHz Pentium II, • 128 MB memory, • 1 shared differential SCSI bus • DEC RA310 RAID array • 1 RAID 5 set • 25 GByte disk space RA310 DS6200 128MB DS6200 128MB HEPNT - Windows NT Days

6. PDC BDC BDC RAID Set RAID Set WINS WINS DFS HD NI DESY Hamburg LAN SQL SMS 4 MBIT Leased Line Print Data Replication DESYNT File Server DESY Zeuthen LAN The DESY WindowsNT Infrastructure HEPNT - Windows NT Days

7. MS Dfs at DESY • MS Dfs is a redirector for UNC requestssingle tree structure for multiple shared volumes located on different serversredirection of client connections to shares via redirection table on the Dfs server • Hardware • standard DESY server configuration • DEC Prioris, 200MHz Pentium Pro, 128 MB memory, Fast Ethernet • NT4 Server, SP3 • Performance • Server • CPU consumption less then 5 % • 40 MB memory ( ~ 3000 entries ) • Client: • first connection takes some time 0.5 to 2 seconds • Dfs cache is updated regular (not for active connections) • no performance losses (compared to a “direct” connection) HEPNT - Windows NT Days

8. Maintenance • simple • daily backup of the configuration table • using the scheduler service • private dump utility • dfscmd /view … > …./full separates with blanks !!  useless • restore by the help of dfsadmin (~30 minutes) • Replication of the configuration table between Hamburg and Zeuthen HEPNT - Windows NT Days

9. Experiences • very useful service • used to provide (read) access to all home directories • not used to connect the user home directory (direct share connection) • used to provide access to the NetInstall applications or other shared offered applications and disk space • simple fail-over by using the alternative path • replication of file space - unique file/directory structures on servers • partial used between Hamburg and Zeuthen (NetInstall packages) • ACL handling is difficult up to NT4 with SP3 • no GUI to handle the ACL’s • only the command line tools cacls and xcacls are available • full integration in to the Explorer with SP4 HEPNT - Windows NT Days

10. Dfs Summary • Advantages • it´s not a gateway, just a small redirector • no performance losses • easy to configure and to maintain • small load for client and server • Disadvantages • it´s a redirector, not a gateway • one can not reconfigure the client • client decides when the internal cache has to be updated • no nested links/redirections • ACL handling not integrated as desired • single point of failure - up to now not integrated in cluster solutions HEPNT - Windows NT Days