Hello lists (cross-posted to linux-390 and IBMVM),
Here's a bit of a blog on an IBM Redbooks residency that started yesterday
in Poughkeepsie, NY: we got funding this year to update "The
Virtualization Cookbook", this time as an official IBM Redbooks
publication. We have a great team of five residents representing four
continents, IBM, Red Hat, SUSE and a customer. We have varying degrees of
Linux and z/VM skills and four weeks to complete most of the work. We're
working towards and hoping for good fruits from this effort.
The main goal is to update the book for the latest levels of Linux and
z/VM. RHEL 6.4 has already GA'd and I believe the next versions of SLES
and z/VM have been announced for July. So it may be a *bit* early to
start this effort, but the timing is still pretty good. With the little
spare time that may be left, we'd like to add new "recipes" to describe
useful topics and tasks.
Yesterday on day 1, we "hit the ground running" and got a 2-node SSI
installed onto two LPARs on different CECs. Already this exposed an issue
(limitation?) with the current book which was written using two LPARs on
the same CEC. In that environment, the OSA real device addresses were
identical on each LPAR. So consider the current example on page 67 which
shows statements added at the bottom of the z/VM SYSTEM CONFIG file in a
2-node SSI:
/* Add EQID statements for OSA addresses and unique MAC IDs */
POKDEV62: begin
rdev 4200-420f eqid osaset1 type osa
rdev 4300-430f eqid osaset1 type osa
vmlan macprefix 02000b
vmlan limit transient 0
POKDEV62: end
POKTST62: begin
rdev 4200-420f eqid osaset1 type osa
rdev 4300-430f eqid osaset1 type osa
vmlan macprefix 02000c
vmlan limit transient 0
POKTST62: end
/* Define VSWITCHes: VSW1 - layer 3, VSW2 - layer 2 */
define vswitch vsw1 rdev 4203 4300 ip
define vswitch vsw2 rdev 4206 4303 ethernet
Note the two VSWITCH definitions are not within the conditional sections.
If the OSA addresses are different (for example, if the second LPAR has
5xxx OSA addresses instead of 4xxx) they have to be pulled into the
conditional statements. For example:
/* Add EQID statements for OSA addresses and unique MAC IDs */
POKDEV62: begin
rdev 4200-420f eqid osaset1 type osa
rdev 4300-430f eqid osaset1 type osa
vmlan macprefix 02000b
vmlan limit transient 0
define vswitch vsw1 rdev 4203 4300 ip
define vswitch vsw2 rdev 4206 4303 ethernet
POKDEV62: end
POKTST62: begin
rdev 4200-420f eqid osaset1 type osa
rdev 4300-430f eqid osaset1 type osa
vmlan macprefix 02000c
vmlan limit transient 0
define vswitch vsw1 rdev 5203 5300 ip
define vswitch vsw2 rdev 5206 5303 ethernet
POKTST62: end
This will be described in the updated book to be more complete.
Also note the examples currently show both a layer 3 and a layer 2
VSWITCH. I believe both DHCP and IPv6 require layer 2 VSWITCHes, and
customers may well be moving to both in the future. As such, we will no
longer give examples of layer 3 VSWITCHes. Rather, we have discussed
defining two layer 2 VSWITCHes such that the first one will allow access
for each Linux (eth0) to and from the cloud, while the second one will
allow each Linux (eth1) to communicate on a "private interconnect". I
know that Oracle CRS (aka "grid") requires such an environment, and that
it can be useful for security reasons (keep the small back door, but lock
the big front door if it's not needed :)).
In a non-SSI or a one member SSI environment, a VSWITCH with no rdevs will
suffice (think Guest LAN), but in a 2, 3 or 4 member SSI environment,
VSWITCHes with no rdevs would create 2, 3 or 4 "islands" of connectivity.
Has anyone created a "private interconnect" that allows communication just
among all SSI members? Thanks.
"Mike MacIsaac" <mikemac at-sign us.ibm.com>
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