System information

4 Sharing and maintaining SLES 10 SP2 Linux under z/VM
During the boot process, read-write copies of the directories /etc/, /srv/, and /root/ are
bind-mounted from /local/ over the read-only copies, while /var/ is its own minidisk. There
is a background discussion on bind-mounts in section 1.3.5, “Overview of bind mounts” on
page 14.
Figure 1-1 shows a block diagram of the entire system. The boxes above the dashed line
represent a maintenance system for conventional Linux servers with most file systems being
read-write. The boxes below the line represent the read-only root portion of the solution.
Figure 1-1 Block diagram of read-only root system
The names of the z/VM user IDs are chosen to convey their function:
S10GOLD The golden systems are stored on this virtual machines disks but
never booted.
S10RWMNT The read-write system on which maintenance is done
S10RWTST The read-write system on which testing is done
S10ROGLD The virtual machine with the generated read-only system
LNXCLONE A user ID to run a Linux script to clone a read-only root system
CMSCLONE A user ID to run REXX cloning EXECs (CMS files)
LNX226 The first read-write cloned Linux with the last octet of the IP address
being 226
LNX227 The first read-write cloned Linux with the last octet of the IP address
being 227
S10GOLD
11Bx disks
21Bx disks
RO2GOLD
MNT2GOLD
MNT2TST
TST2MNT
mnt2rogld.sh
CLONERO CLONERW
REXX
EXEC
Linux script
z/VM user ID
Key:
CMSCLONE
REXX EXECs
Shared 191
S10RWMNT
1Bx disks
9.60.18.222
LNXCLONE
Linux scripts
9.60.18.225
S10RWTST
1Bx disks
9.60.18.222
S10ROGLD
1Bx disks
9.60.18.222
LNX226
1Bx r/w disks
R/W clone
9.60.18.226
LNX227
1Bx r/o disks
R/O clone
9.60.18.227