Jumpstarting a SPARC over the WAN
A post was recently made to comp.unix.solaris, where someone asked if he could Jumpstart several T2000s that he had hosted in a remote facility. He had no administrative access to the remote network, and apparently the other admins (being Windows monkeys) could not be relied upon to set up DHCP and the traditional TFTP/NFS infrastructure.
To make things worse, he had ONLY the remote T2000s. He had no matching-architecture local machines to build a FLAR on.
A number of responders told him (in essence) that he was screwed, that he'd have to take a laptop or something into the colo facility and Jumpstart at least one.
But I read that and thought, "That can't be right." Certainly, taking a machine in (or, more likely, just an install DVD) would be the EASIEST solution. But was it the ONLY solution?
Most SPARC administrators are familiar, at least passingly, with Jumpstart. You set up your infrastructure - namely, a DHCP or RARP server, and an NFS server - hop on the PROM, and and one "boot net - install" and interminable wait later, you've got a fully installed and functioning machine. The feature is also available for x86, since a huge majority of machines come with PXE capability.
However, lesser-known is that modern OpenBOOT PROMs are actually capable of being told their networking information, and not relying completely on DHCP or RARP. This is done with the network-boot-arguments OpenBOOT variable. This is documented in the eeprom(1M) manpage. With this variable, you can supply OpenBOOT with pretty much everything it needs to start up a working, routable IP connection, which can be used to fetch the next-stage bootloader, wanboot, over HTTP.
Traditionally, Jumpstarting in this manner causes the system to try and build via an HTTP-fetched FLAR. Certainly, if you can build a FLAR even vaguely matching the box you're trying to build, this would be the easiest solution. Even if it didn't entirely match your needs, it's enough of a starting point to get a useable Jumpstart platform for the other boxes in the rack.
But, in this person's case, a FLAR wasn't feasible. He was able to export the install media via NFS, and NFS works fine, if slowly, over a WAN. But how to get the installer started in the first place?
(As an aside, Sun - or the community - should really try to figure out a means of building a FLAR for one architecture on another. But, then, with the new packaging/install system coming, perhaps there's hope that FLAR and Jumpstart itself might become obsolete.)
The scripts which start the Jumpstart process make a number of assumptions... some reasonable, some less-so. One of the most annoying is that it assumes your boot media is the same as your install media. It's more annoying, for the SPARC administrator, because Jumpstarting an x86 box does not make this particular assumption... you can supply "-B install_media=" on the GRUB command-line.
There's hope for the future, as supposedly SPARC will be moving to a GRUB, or GRUB-alike booting architecture for the sake of ZFS boot. But how does that help our poor admin, who doesn't want to drive X kilometres to spend hours in a cold colo facility, surrounded by confused, barbaric Windows admins?
First step, in the next entry, is setting up the wanboot process.
Posted at
09:57PM Sep 02, 2008
by Brandon Hume in Solaris |