wolfwings

This can technically cover a NAS, a file server, a web server, or anything else. In my case, it's being used as a borderline NAS/file server/media server for a household.

All drives are hot-swap, the RAID is heavilly growable (from 4-8TB usable w/ 5 drives up to 16+TB with more drives, all hot-swap), and this is based on the newest tech out there so things are fast, stable, and I'm focussing on the 'easy' side of the 80/20 equation: I'm putting in the 20% of the work that gets 80% of the benefit, so please don't make recommendations like "why didn't you use XYZ file system, or set ABC tunable based on I, J, K, and L aspects of your syetem?" because my answer for all of those is: Because I didn't need to eek out 100% performance.

Even with sub-7200RPM drives, and only five of them, this RAID array built in about 5 hours, and reshapes to/from RAID 6 in around 8-12 hours. A rebuild takes about 6-8 hours, using these relatively slow but modern drives. With a 4k-chunk size, aligned with the 4k sectors, I'm seeing write speeds in excess of 90MB/second, and read speeds in excess of 200MB/second, so this thing can theoretically saturate a single Gig-ethernet link pretty handilly as a file server.

First, this is based on Gentoo. I go with Gentoo because they have a rolling-release schedule, versus a backporting schedule. This server was based on the 29th March 2010 sync-point. It varies very little from the normal Gentoo Handbook. I reconfigured the hard drives in fdisk to 32 sectors per track, 128 heads per cylinder, and adjusted cylinders-per-drive accordingly. This results in 2MB cylinders, which also align with the 4K sector size on newer hard drives no matter what you do in fdisk at that point. All partitions are normal, none of them are the 'RAID automount' type.

MDADM is included in the autobuilt install-CD, so I just used that to configure the RAID initially, then made a filesystem and installed normally on top of it. I specifically tuned the file-system to reserve 1% of the resulting 5.3TB available for root only, instead of making a seperate 'operating system' partition. So there's two partitions on each drive: 1) a 40MB 'boot' partition RAID1 across all drives, and the remainder of each drive as the 'system' partition in RAID5 or RAID6 (your choice, you can change this choice later) for the 'system' partition.

All of this is fairly simple, and the normal Gentoo Installation Handbook steps are taken with one exception: Manual Kernel Configuration, to include initramfs support and add mdadm support.

First, we need to set two packages to include the 'static' USE flag, which forces their binaries to be statically linked so they can be safely included on the initramfs easilly.

1) Make a directory on your new system during the installer:

mkdir /etc/portage

2) Then run these commands:

echo sys-apps/busybox static >> /etc/portage/package.use
echo sys-fs/mdadm static >> /etc/portage/package.use
emerge busybox mdadm

That'll rebuild busybox, and install mdadm as static-linked binaries. Next, a few options to enable on the kernel:

Enable initramfs support, but disable all forms of compression of the initramfs, because the entire image (including the compiled-on initramfs) will be compressed at once instead. I pointed it at the /usr/src/initramfs directory for where to pull the initramfs from. Now, configure that directory:

mkdir -p /usr/src/initramfs/dev
mkdir -p /usr/src/initramfs/proc
mkdir -p /usr/src/initramfs/sys
mkdir -p /usr/src/initramfs/newroot
cp -a /dev/{console,null,tty,tty1} /usr/src/initramfs/dev
chown -R root:root /usr/src/initramfs

Copy your busybox and mdadm binaries to /usr/src/initramfs:

Now, you need to write your 'init' for the initramfs as a shell script. Yes, a shell script. It's tricky to get right, so here's a full copy of the one I use. :-)

#!/bin/busybox sh
/bin/busybox mount -t proc proc /proc
/bin/busybox mount -t sysfs sys /sys
/bin/busybox mdev -s

# We have a basic /dev tree configured now. We can manually assembly the md* devices:
/bin/mdadm -A /dev/md0 /dev/sd?2
/bin/mdadm -A /dev/md127 /dev/sd?1

# We need to 'rebuild' the /dev tree before the md* devices will show up though:
/bin/busybox mdev -s

# Now we can mount the root file system, and drop the temp file systems:
/bin/busybox mount -t ext4 -o ro /dev/md0 /newroot
/bin/busybox umount /proc
/bin/busybox umount /sys

# And finally... switch to the new root filesystem:
exec /bin/busybox switch_root /newroot /sbin/init

# Oh-shit panic code, to drop us to a minimal busybox shell to examine the wreckage:
echo Failure! Press enter to boot a shell instead...
read
exec /bin/busybox sh > /dev/tty1 < /dev/tty1 2>&1

Make that owned by root:root, and RWX permissions for root as a user at least, and you're set. You can now compile your kernel like normal, though it'll end up just shy of 1MB larger than normal due to the initramfs. This is assuming you compile your hard-drive drivers into the kernel, and I recommend leaving your USB drivers as modules so if you leave a USB device plugged in it won't error on you strangely. This is a first-pass init script, better can be done, and note this isn't using LVM's but just raw MD devices for the RAID.

There's a song that I'll admit I've adopted, sorta sworn by just before FC, and I think is one reason I've (for better or worse) taken less shit from others lately and inparticular one of the reasons I've more-or-less blown off people trying to blame me for the various drama that happened at FC that I was involved with.

It's not the best singer, I love the song though, and I'm tempted to try to record my own version if I could find someone to play music for it. It... fits a lot of folks in our fandom, I think. For better or worse.

...since before I could reply to either of your questions on the furcon group the post was simply deleted:

First, flaredragon, we honestly didn't know we were negatively impacting anyone. Nobody, not in suit, out of suit, when we were in the headless lounge, at the piano outside headless, or walking around the 2nd floor, not once did anyone approach us and request we stop.

It wouldn't have required desuiting and running to con-ops, to be frank. Send someone, in or out of suit, anyone, to stick their head out and holler, "Hey! We're practicing for a skit, keep the noise down please?" even and we'd likely have suddenly become very mute sheep, grabbed sharpies and starting making Wile E. Coyote 'baaa' signs instead in the creator's lounge.

And as a note, all of us were sitting front-row right in front of the projector screen, still in suit, listening to your memorial and applauded as best as were able along with everyone else when it concluded.

Second, bush_rat, you're right. You were there first. We should have stopped. If we knew we were annoying anyone. See above. Nobody approached the group that I saw at any time to ask us to stop, if anything we had folks watching the reactions when a husky or what-not would suddenly bray and they'd start cracking up at the strange looks we'd get.

Hell, we had many people start joining in on the braying. The flock did, indeed, grow larger over the course of the night. That made us think folks were enjoying the sillyness. None of us were drunk or anything else, we simply found a simple-to-make noise that all of us stuck in suit could make. Suiters can't clap, and most other animal noises just get muffled to uselessness from the heads, so it was part 'Eureka!' and part 'Yay, a bunch of other folks to goof around with!' rolled together at once.

So, yes, directly walking up and saying, "Hey, this is annoying me. Please stop," is more-or-less what I think you should have done. If the 'perpetrators' don't know the fun they're doing is causing someone harm, and it's purely audible noises they're having fun making? They won't know to stop.