Booting via GRUB 2 prompt - Revision history

Jeremy at 15:06, 6 February 2021

2021-02-06T15:06:14Z

← Older revision		Revision as of 15:06, 6 February 2021
Line 3:		Line 3:
	grub> insmod zfs		grub> insmod zfs
	grub> set root=(hd0,gpt3)		grub> set root=(hd0,gpt3)
	grub> linux /BOOT/ubuntu/HEAD/@/vmlinuz-5.4.0-42-generic boot=zfs zfs_force=1 root=ZFS=rpool/ROOT/ubuntu/HEAD net.ifnames=0 biosdevname=0		grub> linux /BOOT/ubuntu/HEAD/@/vmlinuz-5.4.0-42-generic boot=zfs zfs_force=1 root=ZFS=rpool/ROOT/ubuntu/HEAD net.ifnames=0 biosdevname=0 iommu=pt iommu=1
	grub> initrd /BOOT/ubuntu/HEAD/@/initrd.img-5.4.0-42-generic		grub> initrd /BOOT/ubuntu/HEAD/@/initrd.img-5.4.0-42-generic
	grub> boot		grub> boot
Line 16:		Line 16:
	net.ifnames=0 biosdevname=0		net.ifnames=0 biosdevname=0
	was added to the kernel parameters to ensure that all Ethernet device names use the naming scheme '''<tt>ethX</tt>''' for consistency. That part is not necessary.		was added to the kernel parameters to ensure that all Ethernet device names use the naming scheme '''<tt>ethX</tt>''' for consistency. That part is not necessary.
			And the following:
			iommu=pt iommu=1
			was added to set some IOMMU options I need. That part is not necessary.

	You'll then want to update your initial ramdisk, update grub, and re-install GRUB to be on the safe side.		You'll then want to update your initial ramdisk, update grub, and re-install GRUB to be on the safe side.

Jeremy at 04:07, 6 February 2021

2021-02-06T04:07:26Z

← Older revision		Revision as of 04:07, 6 February 2021
Line 17:		Line 17:
	was added to the kernel parameters to ensure that all Ethernet device names use the naming scheme '''<tt>ethX</tt>''' for consistency. That part is not necessary.		was added to the kernel parameters to ensure that all Ethernet device names use the naming scheme '''<tt>ethX</tt>''' for consistency. That part is not necessary.

	You'll then want to update your initial ramdisk and re-install GRUB to be on the safe side.		You'll then want to update your initial ramdisk, update grub, and re-install GRUB to be on the safe side.
	* Verify /boot is mounted from your boot pool:		* Verify /boot is mounted from your boot pool:
	root@daytapod1 ~ $ findmnt /boot/		root@daytapod1 ~ $ findmnt /boot/
Line 24:		Line 24:
	* Update initial ramdisks for all kernels:		* Update initial ramdisks for all kernels:
	root@daytapod1 ~ $ update-initramfs -k all -u -v		root@daytapod1 ~ $ update-initramfs -k all -u -v
			* Update grub config:
			root@daytapod1 ~ $ update-grub
			Sourcing file `/etc/default/grub'
			Sourcing file `/etc/default/grub.d/init-select.cfg'
			Generating grub configuration file ...
			done
	* Install grub on all disks in the boot pool:		* Install grub on all disks in the boot pool:
	root@daytapod1 ~ $ zpool status bpool		root@daytapod1 ~ $ zpool status bpool

Jeremy at 03:53, 6 February 2021

2021-02-06T03:53:46Z

← Older revision		Revision as of 03:53, 6 February 2021
Line 16:		Line 16:
	net.ifnames=0 biosdevname=0		net.ifnames=0 biosdevname=0
	was added to the kernel parameters to ensure that all Ethernet device names use the naming scheme '''<tt>ethX</tt>''' for consistency. That part is not necessary.		was added to the kernel parameters to ensure that all Ethernet device names use the naming scheme '''<tt>ethX</tt>''' for consistency. That part is not necessary.

			You'll then want to update your initial ramdisk and re-install GRUB to be on the safe side.
			* Verify /boot is mounted from your boot pool:
			root@daytapod1 ~ $ findmnt /boot/
			TARGET SOURCE FSTYPE OPTIONS
			/boot bpool/BOOT/ubuntu/HEAD zfs rw,nodev,noatime,xattr,posixacl
			* Update initial ramdisks for all kernels:
			root@daytapod1 ~ $ update-initramfs -k all -u -v
			* Install grub on all disks in the boot pool:
			root@daytapod1 ~ $ zpool status bpool
			pool: bpool
			state: ONLINE
			scan: scrub repaired 0B in 00:00:03 with 0 errors on Sun Jan 10 00:24:04 2021
			config:

			NAME STATE READ WRITE CKSUM
			bpool ONLINE 0 0 0
			ata-Hitachi_HUA722020ALA330_JK1151YAH6E00Z-part3 ONLINE 0 0 0

			errors: No known data errors

			root@daytapod1 ~ $ grub-install /dev/disk/by-id/ata-Hitachi_HUA722020ALA330_JK1151YAH6E00Z
			Installing for i386-pc platform.
			Installation finished. No error reported.

Jeremy at 03:28, 6 February 2021

2021-02-06T03:28:31Z

← Older revision		Revision as of 03:28, 6 February 2021
Line 6:		Line 6:
	grub> initrd /BOOT/ubuntu/HEAD/@/initrd.img-5.4.0-42-generic		grub> initrd /BOOT/ubuntu/HEAD/@/initrd.img-5.4.0-42-generic
	grub> boot		grub> boot
	~~...~~		</pre>
	~~...~~ kernel ~~messages here ..~~.		That should load the kernel and initial ramdisk. If you are then dropped to an '''<tt>(initramfs)</tt>''' shell, you'll have to manually import the zpool containing the root filesystem:
	~~...~~		<pre>
	(initramfs) /sbin/modprobe zfs		(initramfs) /sbin/modprobe zfs
	(initramfs) zpool import rpool -R /root		(initramfs) zpool import rpool -R /root
	(initramfs) exit		(initramfs) exit
	</pre>		</pre>
	~~I also add~~:		Note: The following:
	net.ifnames=0 biosdevname=0		net.ifnames=0 biosdevname=0
	to ensure that all Ethernet device names use the naming scheme '''<tt>ethX</tt>''' for consistency. That part is not necessary.		was added to the kernel parameters to ensure that all Ethernet device names use the naming scheme '''<tt>ethX</tt>''' for consistency. That part is not necessary.

Jeremy: Created page with "Did your update-initramfs not complete before you rebooted your zfs-on-root Ubuntu install? Here's how to boot it from the GRUB prompt using a previous kernel, assuming that y..."

2021-02-06T03:23:11Z

Created page with "Did your update-initramfs not complete before you rebooted your zfs-on-root Ubuntu install? Here's how to boot it from the GRUB prompt using a previous kernel, assuming that y..."

New page

Did your update-initramfs not complete before you rebooted your zfs-on-root Ubuntu install? Here's how to boot it from the GRUB prompt using a previous kernel, assuming that your '''boot''' filesystem is on '''<tt>(hd0,gpt3)</tt>''', the zfs dataset name of your '''boot''' filesystem is '''<tt>bpool/BOOT/ubuntu/HEAD</tt>''', the zfs dataset name of your '''root''' filesystem is '''<tt>rpool/ROOT/ubuntu/HEAD</tt>''', and you're wanting to boot version '''<tt>5.4.0-42-generic</tt>''' of the kernel:
<pre>
grub> insmod zfs
grub> set root=(hd0,gpt3)
grub> linux /BOOT/ubuntu/HEAD/@/vmlinuz-5.4.0-42-generic boot=zfs zfs_force=1 root=ZFS=rpool/ROOT/ubuntu/HEAD net.ifnames=0 biosdevname=0
grub> initrd /BOOT/ubuntu/HEAD/@/initrd.img-5.4.0-42-generic
grub> boot
...
... kernel messages here ...
...
(initramfs) /sbin/modprobe zfs
(initramfs) zpool import rpool -R /root
(initramfs) exit
</pre>
I also add:
net.ifnames=0 biosdevname=0
to ensure that all Ethernet device names use the naming scheme '''<tt>ethX</tt>''' for consistency. That part is not necessary.