Jordi Molina posted <[EMAIL PROTECTED]>, excerpted below, on Tue, 24 Jan 2006 00:04:06 +0100:
> I installed gentoo from another livecd and then compiled the kernel > and the initrd image to support sata_nv. > > It boots fine for me. Forget about using the nvraid, is not hardware, > so if you need it, go sw raid or buy a decent RAID card. As someone else stated, my info doesn't quite fit your scenario, but it can add to the list. I agree with the above, go sw (preferably kernel-built-in) RAID. I'm running an older (I believe SATA-1) Silicon Image 3114, on a dual Opteron Tyan s2885. Attached to it, I have four Seagate SATA-2 300 gig drives, in mixed-RAID configuration, all using the kernel's software RAID. The fact that I'm using kernel-RAID means that I don't have to worry about hardware RAID compatibility or the like, when this system dies or I simply decide to upgrade. Simply building a new kernel with the standard SATA chipset drivers and installing it to /boot before unplugging my drives and plugging them into the new system, should be all I need to do to port to a new SATA chipset. As I mentioned, four drives, mixed RAID, arranged as follows. A small RAID-1 to boot off of. Since RAID-1 is direct mirrored, I can install GRUB to the MBR of all four drives, and can boot to GRUB from any of the four, by just switching the BIOS to the one I want to boot. GRUB doesn't do RAID, but it sees each of the mirrors individually, which is all that it needs to see the kernel mirrored on each one, so it can boot it. My main system is RAID-6 over the four drives, which means any of the four can die and I'll remain up with little speed degradation, a second one can die, and I'll still have my data, but at significantly reduced speed, until I recover at least to three drives. I was originally thinking about RAID-5 with a hot-spare, but decided RAID-6 without a hot-spare is effectively the same thing, only with more protection because the second drive can die before the hot-spare could have been brought online, and I'll still be fine. Stuff like /tmp, /var/tmp, and the portage tree and distdir, are on RAID-0, to maximize speed and space usage, because that's either non-critical data or stuff that can be redownloaded off the net rather quickly in any case. I have swap distributed across the four drives as effectively a RAID-0 as well, as they are all set at the same priority, which allows the kernel to manage them effectively as RAID-0. If a drive or two dies, therefore, I'll go down, but can come right back up by simply reconfiguring the swap and RAID-0 for two or three drives instead of four, remaking the RAID-0, and running that way if necessary until I can procure another 300 gig drive or two to get back to normal operation. I don't have to use an initrd at all. With a couple kernel parameters, the kernel can find and reassemble the RAID-6 upon which my root file system is based, without an initrd. I did choose to use partitioned RAID-6 (partitioned RAID is possible on 2.6, with an additional kernel command line append telling it which RAIDs to load partitioned) for my root and root-backup-image filesystems, rather than LVM, thus avoiding the complication of initrd/initramfs, which LVM would require. However, the rest of my RAID-6 data is on another RAID-6 partition, which is LVM-2 split in ordered to be more dynamically manageable, into my other logical volumes (home and home-backup-image, media and media-backup-image, log, which I decided I didn't need a backup image for, mail and mail-backup-image, etc). The backup images are there to prevent the one thing RAID redundancy does NOT protect against -- fat-fingered admins! Of course, the root-backup also protects against the occasional issue with a bad update making my working root unbootable, or without a working gcc or portage or whatever, giving me an emergency root backup boot option, whether the main root boot failure is due to my own fat-fingering, or the occasional bad upgrade one might have with ~amd64 plus pulling in stuff like modular-X and gcc-4 before it's even stable enough for ~arch! I've been VERY impressed with the speed improvement of the system, over bog-standard single-disk PATA. Now that I know how much more responsive the system is with 2-4 way striped RAID (a four-disk RAID-6 is effectively 2-way-striped, the RAID-0 is of course 4-way-striped, as is swap), I wish I had done it earlier! As I mentioned at the top, I recommend kernel-RAID, for two reasons. One, it massively decreases porting or upgrade worries, as it's not dependent on specific hardware, only SATA standard hardware. Two, the mixed-RAID implementation I've setup as described above isn't possible, to my knowledge, on hardware RAID. The two combined, plus the fact that I've got a dual processor system already, so the rather small CPU hit of software RAID matters even less, PLUS the fact that I could direct-boot it, something I thought was only possible with hardware RAID, made this by FAR the best choice possible for me. Some of that may apply to your current RAID-1 situation, some not. If you are only going all RAID-1 because you didn't realize you could do mixed-RAID, depending on your usage, you may wish to reconsider doing mixed-RAID, now that you know it's an option. With a two-physical-drive solution, you can at least implement RAID-0 for /tmp and the like, /provided/ that it's not absolutely critical to keep it from going down period. Or you can throw another drive in and make it RAID-5, with a small RAID-1 for /boot and possibly a RAID-0 for non-critical data. ** Something that *WILL* apply to your situation, even (especially) if you are sticking with RAID-1 only -- for installation, you can do a conventional single-drive installation, if necessary, no RAID drivers necessary on the LiveCD. When you build your kernel, just ensure that it includes software RAID built-in, along with the regular SATA chipset drivers. Then, after you are up and running on the single drive, create a "degraded" RAID-1 on the second drive, activate it, partition it if you have it setup as partitionable RAID, create your filesystems on it, mount them, and copy your system over from the single drive to the degraded-but-operational RAID-1. Once that's done and GRUB is installed too the MBR of the degraded RAID-1, reboot onto the degraded RAID-1, and then activate what WAS your single drive as the second RAID-1 drive. It'll take some time to mirror everything over, doing its recovery cycle, destroying the single-drive installation in the process, but when it's done, you'll have a fully active non-degraded RAID-1 going, all without requiring the RAID drivers on the LiveCD, only the standard SATA drivers. The process of installing a RAID system in this manner, by installing to a single drive then activating the RAID in degraded mode to copy everything over, before bringing in the single drive as the missing one and recovering, is covered in more detail in the various RAID HOWTOs and Gentoo documentation. -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman in http://www.linuxdevcenter.com/pub/a/linux/2004/12/22/rms_interview.html -- [email protected] mailing list
