[gentoo-amd64] Can initrd and/or RAID be disabled at boot?

[Mark Knecht <markknecht@gmail.com>]

Hi,
   This is related to my thread from a few days ago about the
disappointing speed of my RAID6 root partition. The goal here is to
get the machine booting from an SSD so that I can free up my five hard
drives to play with.

SHORT SUMMATION: I've tried noninitrd and noraid in the kernel line of
grub.conf but I keep booting from old RAID instead of the new SSD.
What am I doing wrong?

   What I've done so far:

1) I've removed everything relatively non-essential from the HDD-based
RAID6. It's still a lot of data (40GB) but my Windows VMs are moved to
an external USB drive as is all the video content which is on a second
USB drive so the remaining size is pretty manageable.

2) In looking around for ways to get / copied to the SDD I ran across
this Arch Linux page called "Full System Backup with rsync":

https://wiki.archlinux.org/index.php/Full_System_Backup_with_rsync

Basically it boiled down to just a straight-forward rsync command, but
what I liked about the description what that it can be done on a live
system. The command in the page is

rsync -aAXv /* /path/to/backup/folder
--exclude={/dev/*,/proc/*,/sys/*,/tmp/*,/run/*,/mnt/*,/media/*,/lost+found}

which I have modified to

rsync -avx /* /path/to/backup/folder
--exclude={/dev/*,/proc/*,/sys/*,/tmp/*,/run/*,/mnt/*,/media/*,/lost+found}

because I don't use (AFAICT) any of the ACL stuff and the command
simply wouldn't do anything.

I ran this command the first time to get 98% of everything copied
while in KDE, but before I moved forward I exited KDE, stopped X and
ran it as root from the console. After the second run it didn't pick
up any new file changes so I suspect it's pretty close to what I'd get
dealing with a Live CD boot. (COMMENTS?)

3) I added a new boot options in grub.conf:

title fastVM 3.8.13-gentoo using LABEL (SSD, initramfs in kernel)
root (hd5,0)
kernel (hd0,0)/boot/bzImage-3.8.13-gentoo root=LABEL=fastVM
video=vesafb vga=0x307title

fastVM 3.8.13-gentoo using LABEL (SSD, initramfs in kernel)
root (hd5,0)
kernel (hd0,0)/boot/bzImage-3.8.13-gentoo root=/dev/sda1 video=vesafb vga=0x307

I am relatively confident that (hd5,0) is the SSD. I have 6 drives in
the system - the 5 HDDs and the SSD. The 5 hard drives all have
multiple partitions which is what grub tells me using tab completion
for the line

root(hdX,

Additionally the SDD has a single partition to tab completion on
root(hd5 finishes with root(hd5,0). I used /dev/sda as that's how it's
identified when I boot using RAID.

   Now, the kernel has the initrd built into it so if it cannot be
turned off I guess I'll try building a new kernel without it. However
I found a few web pages that also said RAID could be disabled using a
'noraid' option which I thought should stop the system from finding
the exiting RAID6 but no luck.

  Does anyone here have any ideas? fdisk info follows at the end. Ask
for anything else you want to see.

   If I can get to booting off the SSD then for the next few days I
could build different RAIDs and do some performance testing.

Thanks,
Mark



c2RAID6 ~ # fdisk -l

Disk /dev/sda: 128.0 GB, 128035676160 bytes, 250069680 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xfd2e963c

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1            2048   250069679   125033816   83  Linux

Disk /dev/sdb: 500.1 GB, 500107862016 bytes, 976773168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x8b45be24

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1   *          63      112454       56196   83  Linux
/dev/sdb2          112455     8514449     4200997+  82  Linux swap / Solaris
/dev/sdb3         8594775   976773167   484089196+  fd  Linux raid autodetect

Disk /dev/sdc: 500.1 GB, 500107862016 bytes, 976773168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x703d11ba

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1   *          63      112454       56196   83  Linux
/dev/sdc2          112455     8514449     4200997+  82  Linux swap / Solaris
/dev/sdc3         8594775   976773167   484089196+  fd  Linux raid autodetect

Disk /dev/sde: 500.1 GB, 500107862016 bytes, 976773168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xce92d9ff

   Device Boot      Start         End      Blocks   Id  System
/dev/sde1            2048     8594774     4296363+  83  Linux
/dev/sde3         8594775   976773167   484089196+  fd  Linux raid autodetect

Disk /dev/sdf: 500.1 GB, 500107862016 bytes, 976773168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x21141305

   Device Boot      Start         End      Blocks   Id  System
/dev/sdf1            2048     8594774     4296363+  83  Linux
/dev/sdf3         8595456   976773167   484088856   fd  Linux raid autodetect

Disk /dev/sdd: 500.1 GB, 500107862016 bytes, 976773168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xfb3ad342

   Device Boot      Start         End      Blocks   Id  System
/dev/sdd1   *          63      112454       56196   83  Linux
/dev/sdd2          112455     8514449     4200997+  82  Linux swap / Solaris
/dev/sdd3         8594775   976773167   484089196+  fd  Linux raid autodetect

Disk /dev/md3: 1487.1 GB, 1487118827520 bytes, 2904528960 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 16384 bytes / 49152 bytes

c2RAID6 ~ #