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Cloning Windows NT Systems. Mainly based on experiences at RAL and Oxford. Windows NT at RAL. Office systems NT based. Use Exchange server / Outlook 98. Client for financial system on NT. SMS used centrally to upgrade some 570 PCs. (E.g. NT 3.51 -> 4 and Office 95 -> 97 upgrades.)
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Cloning Windows NT Systems Mainly based on experiences at RAL and Oxford.
Windows NT at RAL • Office systems NT based. • Use Exchange server / Outlook 98. • Client for financial system on NT. • SMS used centrally to upgrade some 570 PCs. (E.g. NT 3.51 -> 4 and Office 95 -> 97 upgrades.) • Some services on NT (databases, dial-in, DHCP) • NT farm for HEP use.
Windows NT in RAL Particle Physics Department Windows NT on Desktop. Access to Unix, VMS servers via X (Exceed). • Two main servers: One Intel, One Alpha. • Desktop (Intel) systems cloned. • Buy PCs in batches - not all identical.
Topics Covered • Design Goals for Desktop Systems. • Methods of Cloning. • Issues in cloning applications. • Experiences. • Disadvantages / Advantages of cloning. • Laptops.
Issues / Goals for Desktop Systems • Minimise Support Effort & Cost • Setup a good environment for the user • e.g. sensible defaults • Systems (sufficiently) similar a user can move between them and still see the same environment. • Can replace system in event of ‘failure’. • Users’ files (including configuration files etc.) stored on server.
Specific Examples... • Storing a users configuration for the application back on the server (e.g. Netscape bookmarks) • Default location for saving files to be on the server not the local hard disk of the PC. • No backups made of desktop systems.
What methods are there for setting up NT? • Separate installs on each PC • Use SMS • Some form of duplication of a ‘master’ setup: • NICE • Simple cloning • Zero Admin Windows
Methods of Cloning • NT Install/Backup • Disk Imaging (Ghost, DriveImage) • SYSDIFF
Using NT Install/Backup • On Master System • Backup the registries (to files). • Make a Backup. • On Target System • Install NT to same level as Master (install options, network setup, service pack) • Backup (overwrite) from Master • Replace software & default registry hives • Patch-up
Disk Imaging • Various commercial products available. • Ghost from Norton. • DriveImage from Powerquest. • Make image of master system’s disk. (Place on server) and load down onto target machines. • Some patch-up needed: • Load any different drivers (video and network cards) • Modify name & IP address. • Use SID changer.
SYSDIFF • Resource kit utility. • Snapshot systems (registry and files). • Records differences since a snapshot and can apply those differences to another system. • Problems with NT service packs.
Some issues in cloning an application. Application made up of: • Executable Files etc. • Initialisation/Configuration Files (initial & modified) • Per machine • Per user • Registry Settings (initial & modified) • Per machine (HKEY_LOCAL_MACHINE) • Per User (HKEY_CURRENT_USER)
Where do these come from? • Executable Files Application install • Ini. /Conf. Files • Per machine Application install • Per user Application install • Registry Settings • Per machine (HKLM) Application install • Per User (HKCU) Application install
Where do these come fromon a cloned system? • Executable Files cloning • Ini. /Conf. Files • Per machine cloning • Per user copy in (at login) • Registry Settings • Per machine (HKLM) cloning • Per User (HKCU) copy in (at login)
Experience with Cloning (1) Oxford University Physics Department • Use Ghost. • Approaching 200 systems supported • Update ‘on demand’ • Some tidy-up via nightly batch job.
Experience with Cloning (2) RAL • Use of Install/backup works. (Approximately 50 systems installed.) • However, rather too heavy for updating regularly. • Moving to using DriveImage and SYSDIFF. • Problems with large packages required by a smaller number of users. Solution: • Install onto server • Control access via ACLs.
Disadvantages • Updating of cloned systems from time to time. Not suitable as it stands for very large sites. • If a user adds their own software to ‘their’ system this may be ‘lost’ during an upgrade. • All applications distributed to all systems. (May need to buy ‘unnecessary’ licenses.) • Can we have problems with different hardware in PCs that is not handled correctly by cloning? • (Not the same setup as elsewhere at RAL.)
Advantages • Easy to build/rebuild systems • No need to backup workstation disks • Simple route to recover from problems • Same set of applications everywhere. • Study how to setup an application once, then duplicate. • Can setup applications such that • Users have their own configurations that move with them. • Novice users find sensible defaults. => Lower maintenance overheads.…
LAPTOPS • Problems Cloning to Laptops: • Hardware very different to desktop systems. • Model of ‘standard system’ does not apply: • Cannot have all configuration files etc. on server. • Systems personalised - difficult to update by overwriting. • SYSDIFF offers method of applying/updating applications. • If share environment with desktops, important to choose carefully which applications are server-based.
Summary • Cloning works for a moderate size department ( <100? ) • If you have a reasonable set of applications, many users content. • Comprises a set of simple tools that interwork. • Benefits from knowing setup the same on all systems.