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 > 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.Ghost –DriveImage from Powerquest.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 FilesApplication 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 from on a cloned system? Executable Filescloning Ini. /Conf. Files –Per machinecloning –Per usercopy 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.