Windows/Linux Coexistence : VMware Approach

1. Windows/Linux Coexistence :VMware Approach HEPix – LAL Apr. 2001 Michel Jouvin jouvin@lal.in2p3.fr VMware - HEPix - LAL 2001

2. Outline • Linux on desktop demand • Dual boot limitations • Vmware concepts and requirements • Possible configurations • LAL configuration and experience VMware - HEPix - LAL 2001

3. Some users want Linux… • Desktop similar to server platforms • A real issue mainly for laptops • Anti-Microsoft feelings • Everything coming from MS is bad and unnecessarily expensive • Need for very specific applications VMware - HEPix - LAL 2001

4. But… (User) • Need access to Windows applications (Office) • Native Linux tools not compatible enough to handle all the documents produced by MS tools • StarOffice is too slow (one huge application) VMware - HEPix - LAL 2001

5. But... (Management) • LAL restrictions • No NFS export to Linux desktop • Almost everything exported to LAN Manager • Linux NFS performances are poor • No manpower to support users • SMBFS is not an alternative • Few people really interested by a pure Linux desktop VMware - HEPix - LAL 2001

6. Dual Boot Deficiencies • User • You always need access to the other OS tools • You need a file that is on the other OS disk • User wants access to both OS at the same time • Management • You never know what OS is running • Defeats the automatic management tools • Unattended installation tends to format the disk • Unable to propagate critical patches VMware - HEPix - LAL 2001

7. Vmware Concept • Run on 1 machine several OS at the same time • No emulation involved • Each OS instance sees a “real” machine • You can run several instance of the same OS • Vmware available for both Linux and Wxx • Application gives another view of hardware • Power on/off + BIOS setup + ... • Need to install and maintain the guest OS with standard procedure VMware - HEPix - LAL 2001

8. Vmware Requirements • Memory : static sharing • 256 Mo minimum (128 Mo / OS) • Disk space • Enough space for both system disks • Rest of the hardware is shared dynamically • Graphic driver • Vmware provide a driver for the guest OS • Else cursor bounded at guest OS window border VMware - HEPix - LAL 2001

9. Disk Configuration… • Different disk partition for each OS • Static partitioning : reconfiguration difficult • Specific tools like PartitionMagic required • MBR sharing : same OS boot by default in both machines VMware - HEPix - LAL 2001

10. … Disk Configuration • Virtual disks • One file on the main OS disk presented as a disk to the guest OS • Will be partition with FDISK, fsck, … • Will grow according to real use until max size • Hard limit = 2 Go • Can be shrinked is usage lowered • Performance penalty • Not an issue for system disks • Advanced feature like modification rollback VMware - HEPix - LAL 2001

11. Network Configuration… • Host-only • Guest OS has an address in a non routed subnet • DHCP usable but DHCP must be on main OS • + : Consume only one address / physical machine • + : Communication possible between both OS when disconnected from the net • - : Guest OS has no access to the network VMware - HEPix - LAL 2001

12. … Network Configuration • Bridged • Guest OS has a separate address • DHCP usable (ability to give a unique MAC to VM) • + : Guest OS has access to the network • - : 2 addresses / physical machine • - : No communication between machines if disconnected from the network • Ability to use bridge + host-only VMware - HEPix - LAL 2001

13. Guest OS = W2000 • The most natural for the user but… • High management cost (> 2 machines) • No tool (at LAL) for fully unattended Linux installation • Kixtart (at LAL) will format the disk • W2000 : impossible to clone VM (SID pb) and/or unable to use automatic update tools • Full OS installation needed VMware - HEPix - LAL 2001

14. Guest OS = Linux • Same service as previous solution • Low management cost • W2000 installed and managed by standard tools • Linux installation = copying a reference VM • One virtual disk used for Linux system disk • Network configured by DHCP • W2000 PnP better Linux PnP support • Hardware is managed by the main OS VMware - HEPix - LAL 2001

15. W2000/Linux File Sharing • Use shared folders on W2000 side • Can restrict access to the username used for sharing • On Linux, connect the folder with smbmount • Smbclient must be installed • Security issues can be ignored on a VM • Connect through the host-only interface to be independent of the network • Use a local account on W2000 to be able to connect even without network connection VMware - HEPix - LAL 2001

16. Linux/W2000 File Sharing • Use Vmware pre-configured samba to export Linux filesystems • Use Network Neighborhood on W2000 to access Linux filesystems • Use a local account + host-only interface to connect to the Linux machine VMware - HEPix - LAL 2001

17. Linux in VM Issues • Usual cron jobs are not run (VM is off) • Need to take care of /tmp cleaning at startup • Caution not to break some apps (gdm) • Need to run Vmware-tools as root to get time synchronization • Is a GUI so impossible to start during boot • At LAL, it has setuid bit set • Needed on W2000 too but run as a service VMware - HEPix - LAL 2001

18. LAL Configuration • Main OS = W2000, Guest OS = Linux • Network : host-only or host-only + bridged • Linux Sys disk : 1 generic virtual disk (2 Go) • Can be replaced to upgrade Linux version • Main customization required : keyboard layout • /home and personal dirs : 1 other virtual disk (2 Go) VMware - HEPix - LAL 2001

19. LAL Preliminary Conclusions • Early deployment : 5 users • Seem very satisfied • Performance doesn’t seem an issue • One VM running AFS (laptop) • AFS should not be started at boot time • Takes a long time if disconnected from the net • Is Vmware useful on non laptop ? VMware - HEPix - LAL 2001

20. Future Directions • Network configuration • Use NAT on Windows to give VM a network access • Only one address per machine • Easier (more generic) pre-configuration of Linux VM VMware - HEPix - LAL 2001