Hi. I couldn't see this otherwise filed so apologies if it /is/ a dup. Background ========== It seems to be impossible to set up RAID from the 1.4_rc1 LiveCD. There have been a few reports to this effect on the "Installing Gentoo" section of the forums. Symptoms ======== The mkraid command does not work. There are no /dev/md* devices available, nor is "md" provided as a kernel module. It seems that only LVM support, "lvm-mod", is available as a kernel module. It seems that the only way around this is to boot from the 1.2 CD and then proceed with a 1.4 tarball. It makes using EVMS a bit of a drag (I'm still trying to suss out how to do a RAID/LVM combo with the evsmn utility)!
A little OT perhaps, but I've been experimenting with "evmsn" and if a: > insmod lvm-mod is issued first then it should be possible to achieve the same results with evmsn. In fact, the above is *necessary* for evmsn to function properly at all (the creation of normal logical volumes is necessary before they are exportable as "enterprise" volumes at the top of the stack). Nonetheless, many may wish to stick with tools they know and trust. After inserting that module (and after much head-scratching and experimentation in a virtual machine) I was able to determine how to create RAID arrays, volumes, feature containers and more. Thinking out loud: perhaps this could go into a Gentoo Server Guide at some point?
evms (built in to the kernel) is incompatible with md. I'd need to tweak the initrd to allow one to select one or the other with a kernel boot option. This may not happen for 1.4 but will probably happen at some point.
*** Bug 11245 has been marked as a duplicate of this bug. ***
Fixed on the 13 Jan 2003 (and later) livecds.
Hi Daniel, I've reopened this because the problem still seems to be occurring with a 1.4_rc2 Pentium III GRP boot CD which I am testing in VMware with 4 virtual SCSI hard disks. I had assumed all was well with the later boot CDs and am using VMware to help me write some detailed documentation about setting up Gentoo on a server (more on that here: http://forums.gentoo.org/viewtopic.php?p=185742) recreating the procedures that I went through. I was suprised to see that no /dev/md* nodes are created, despite that RAID is now obviously compiled into the kernel used on the CD. Given that EVMS is currently impossible to set up, that kind of leaves one between a rock and a hard place! Above, you stated that "evms (built in to the kernel) is incompatible with md." Does that mean that it will not be possible to use conventional RAID (wihout jumping through hoops with the aged 1.2 CD) in the immediate future or even for the 1.4 release? It's an issue close to me heart because I think that most people setting up RAID on servers will not feel that they are "ready" for EVMS just yet (particularly in light of the fact it hasn't been accepted into the official kernel tree yet, is comparatively young and already there are issues), however good a technology it may be. As it stands, it's really quite awkward to set up a typical enterprise server with a standard Linux-based RAID implementation and the goalposts seem to keep moving, as it were. If the answer to the previous question is yes, then couldn't we simply have multiple options on Grub ("Gentoo Linux (EVMS enabled)" / "Gentoo Linux (EVMS disabled"), with disabled as a default - or is it not that simple? Or maybe even just have a separate EVMS enabled x86 CD? I really would like to push Gentoo for server use with what I'm writing, it's a beautiful distro and I probably wouldn't even be running Linux as a server now but for your hard work and excellent articles. But having to use combinations of boot CDs to get the job done is, IMHO, going to make for complicated and offputting reading! The 1.2 CD is also out-of-date and doesn't seem stable on all systems (it oopsed some modules when I set up my Compaq server, although I got through it). It also means the sysadmin has to put more effort into the preparation of a rescue CD, because the current CD will presumably not be able to do anything with the existing RAID volumes. Many thanks.
I agree that EVMS shouldn't be on the frontlines; people will fall back on a more conservative distribution if they see that Gentoo doesn't give them the option of doing normal RAID; I have a system here on which Gentoo would be quite attractive, and will have to employ several workarounds to get it done with standard RAID.
normal raid and evms is working on latest cds, boot with "gentoo noraid" to not load evms modules if needed.
Moving these so we can remove the "Install CD" component from "Gentoo Linux". I apologize to everyone for this spam, but according to the bugzilla developers, this is the only reasonable way to do this.
