John Summerfield writes: > On Thu, 5 Sep 2002 01:01, you wrote: > > However, using a VQDIO Guest LAN on a z900 (31-bit mode), and sharing > > /usr but nothing else, it was taking us (when the machine wasn't doing > > anything else much) about 3 minutes. Almost all of that was spent > > copying /; if we had had FlashCopy or something like that, I'd guess, > > based on the way we did it, which relied on DIRMAINT and 2 IPLs on Linux > > per guest (first time it comes up generic; it uses CMSFS to read stuff > > the cloning process put on its 191-disk to determine hostname, IP > > address, etc., and then write that onto the real filesystem and reIPL) > > about 30 or 45 seconds. > > You should be able to do that configuration on the first boot and keep right > on going. > > Two ideas. This is part of my inittab from RHL 7.3 on the desktop. > id:5:initdefault: > > # System initialization. > si::sysinit:/etc/rc.d/rc.sysinit > > Change it to read: > id:5:initdefault: > # One-time initialisation > 1t:12345:once:/etc/rc.d/first-time > > # System initialization. > si::sysinit:/etc/rc.d/rc.sysinit > > /etc/rc.d/first-time is a script that exits immediately if the system's > already been set up; otherwise it does the stuff defined by the 191-disk. > > > Second, front-end /etc/rc.d/rc.sysinit by changing the line: > si::sysinit:/etc/rc.d/rc.sysinit > > Note too that the kernel can be built with DHCP support.
I'm recently back from a redbook residency where we wrote a redbook on "Linux on IBM zSeries and S/390: Large Scale Linux Deployment". Two of the parts of that redbook are particularly relevant to topics which have been raised on this list recently. One is about resource sharing and cloning and introduces a new way of splitting up the readonly and readwrite parts of a Linux guest such that you can use a single small readwrite volume (e.g. 20 cyls, 15 MB) for a small guest. (It also handles RPM management across the readonly and readwrite parts, although still not ideally.) An auto-configuration part (handled by a small VM configuration server guest using PROP) lets a new clone come up, find out its management network address, couple itself to the management GuestLAN, use that to query a central configuration LDAP server, pick up its complete "service" configuration information (IP address, role, etc.) from there and boot fully into service. On our particular hardware, it took 30 seconds from hitting Enter on the initial "create new guest" command until the appearance of the root prompt after ssh'ing to the new guest. That broke down as about 10 secs for the DIRMAINT guest creation, 10 secs DDR copy of the "gold" guestvol (the readwrite volume) and 10 secs of the guest booting, finding its network information, configuring the network, creating its first sshd key (takes a while) and having me make an ssh client connection to it. The basevol+guestvol system does indeed work by changing the rc.sysinit step of boot time. A cloned guest actually boots from the readonly basevol its linked to (no more problems with corrupting your bootable root fs) which looks for its guestvol at address 777. If found, it mounts it in a special way and binds in parts of that filesystem as all the necessary writable parts of the main filesystem hierarchy (the book explains about how "mount --bind" works). It then kicks init to continue with the rest of the boot process in the normal way, now from the guestvol's /etc/inittab configuration. It's the next step which then asks the configuration server guest (via CP SMSG) for its basic configuration info so that it can couple to the management GuestLAN. The other part particularly relevant to a topic here is the section on Hipersockets and z/VM GuestLAN (and associated chapters on TCP/IP routing, network high availability and such like.) Those sections were mostly written by Vic Cross and build up on the ISP/ASP redbook now that GuestLAN/Hipersockets is around and has mostly taken over from other options as the recommended connectivity method for Linux guests. I don't yet know when a redpiece will be available or if there is a provisional publishing date. --Malcolm -- Malcolm Beattie <[EMAIL PROTECTED]> Linux Technical Consultant IBM EMEA Enterprise Server Group... ...from home, speaking only for myself
