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

[Bob Sanders <rsanders@sgi.com>]

Mark Knecht, mused, then expounded:
> 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?
>

Can the boot order be changed in the bios?

Was grub-install run on the SSD and saved to the SSD's MBR?

If, possible, can the SATA cables be moved such that the SSD is drive 0?

And, it might be useful to mount by-id or by-uuid -

rsanders@conejo ~ $ ls /dev/disk/by-id/
ata-OCZ_VERTEX-TURBO_408M1550705G08FCFEQB        ata-TSSTcorp_CDDVDW_SH-S223L_Q9896GAZ20018200
ata-OCZ_VERTEX-TURBO_408M1550705G08FCFEQB-part1  md-uuid-3899baf6:daee0dc9:cb201669:f728008a
ata-OCZ_VERTEX-TURBO_408M1550705G08FCFEQB-part2  md-uuid-dfeb347b:7e3b4c57:cb201669:f728008a
ata-OCZ_VERTEX-TURBO_408M1550705G08FCFEQB-part3  wwn-0x50000f00080a0008
ata-SAMSUNG_HE502IJ_S1MTJ1CQA00080               wwn-0x50000f00080a0008-part1
ata-SAMSUNG_HE502IJ_S1MTJ1CQA00080-part1         wwn-0x50000f00080a0008-part2
ata-SAMSUNG_HE502IJ_S1MTJ1CQA00080-part2         wwn-0x50000f00080a0018
ata-SAMSUNG_HE502IJ_S1MTJ1CQA00081               wwn-0x50000f00080a0018-part1
ata-SAMSUNG_HE502IJ_S1MTJ1CQA00081-part1         wwn-0x50000f00080a0018-part2
ata-SAMSUNG_HE502IJ_S1MTJ1CQA00081-part2
rsanders@conejo ~ $ ls /dev/disk/by-uuid/
1011bd2c-14bb-485e-8416-14f82835c4f6  7540a6d2-426d-4272-83f0-34ab7d1ffc83  a5ea4eb8-4797-482f-af80-a60f20a62915
2974c334-cffd-41d6-94c9-23a4d24980be  a26b8632-dabf-450d-806f-330b71b91aeb


/etc/fstab would look like - 

   /dev/disk/by=id/ata-OCZ_VERTEX-TURBO_408M1550705G08FCFEQB-part1   /boot ext2        noauto,noatime  1 2
   /dev/disk/by-id/ata-OCZ_VERTEX-TURBO_408M1550705G08FCFEQB-part3   /     xfs         noatime         0 1

And grub.conf would look something like this SLES example -

title SUSE Linux Enterprise Server 11 SP2 - 3.0.80-0.5
    root (hd0,1)
    kernel /boot/vmlinuz-3.0.80-0.5-default root=/dev/disk/by-id/ata-ST3500514NS_9WJ0KSKX-part2 resume=/dev/disk/by-id/ata-ST3500514NS_9WJ0KSKX-part1 splash=silent crashkernel=256M-:128M showopts vga=0x31d
    initrd /boot/initrd-3.0.80-0.5-default


>    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 ~ #
> 

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