Gentoo as Dual Boot and Recovery

chrisrobinson · n00b Joined: 02 Sep 2016 Posts: 4 Location: Cambridge, MA

I have recently experienced a failure of my current operating system, OpenSolaris to boot to the Gnome desktop. This was probably caused by powering off without shutting down first, although I have done that many times before
without any difficulty. I can bring up a control console, but I can not access any of my files. I have not been able to get any help from the solaris community with this, so I want to install Gentoo as a second boot environment, so
that I can access my files that are on the hard disk in rpool. I need to know whether I can install Gentoo on another partition that will not be destructive to any of my existing data.

mrbassie · l33t Joined: 31 May 2013 Posts: 772 Location: over here

Is this a zpool import problem?
In any case why not install whatever os with zfs support to a usb or a cd?

vaxbrat · l33t Joined: 05 Oct 2005 Posts: 731 Location: DC Burbs

Never used opensolaris myself but did a lot of Solaris back in the day (2.6 - 2.8 mostly). If a fsck preen on boot failed, you would generally be prompted for a root password and then thrown into single user mode. Is this what you are talking about when saying you are getting a control console and not being able to access any of your files? That mode should be sufficient for you to find and fix whatever is going on with your zfs pools. I use btrfs instead of zfs so am not familiar with what sort of maintenance tools come with it.

You should also be able to throw the systemrescuecd iso onto a thumb drive or a cdrom and then boot that to attempt a rescue if your root fs is whacked

chrisrobinson · n00b Joined: 02 Sep 2016 Posts: 4 Location: Cambridge, MA

Mr. Brassie,

Thank you for your reply. This has been a very difficult two weeks and I greatly appreciate all support that I get.
I did try to use the rescuecd-in fact it is up on my machine right now. However, it is dispalying in such tiny
resolution as to be almost unreadable and I can't seem to make any adjustments. I can see a small but readable
control console, however I do not know what commands to use.
I apologize for not being clearer with the opensolaris problem. Let me try again: when the GRUB window comes up, and I select opensolaris2009.06 as the boot environment, the loading icon appears, but keeps circulating without
bringing up the Gnome login screen. If I then press esc I can bring up a control console and list my folders but
can not actually access their contents.
I will try out some of your suggestions, but I am now losing hope in repairing the boot archive (I have tried
bootadm archive-update with no success).
The real reason I am posting to this list is to find out if I can do a non-destructive install of Gentoo and access my
files that way. In other words, can I create a Gentoo partition that will not overwrite the opensolaris one?

C5ace · Posted: Sat Sep 03, 2016 12:04 pm Post subject:

I look after several Gentoo laptops and desktops. I us a 2GB USB drive with Gentoo XFCE installed as backup system. My procedure is to connect the USB drive to the non-booting laptop named for exmple "HP", boot from the USB drive, login as root, run "mount_HP" and then startx.

"mount_HP" script mounts the partitions of of the HP laptop to /mnt/gentoo, /mnt/gerntoo/boot, /mnt/gentoo/home. To avoid confusions all partitions are mounted by LABEL. I.e. USB_ROOT, USB_BOOT, USB_HOME, HP_ROOT, HP_BOOT, HP_HOME, etc. Also the root of each partition has file named the same as the partition (USB_ROOT, etc).

I can now access and modify all file on the HP laptop and if necessary, restore a previously made backup of HP_BOOT etc.

I do not know if you can boot a Solaris Box from a external USB drive or install Gentoo on a USB drive connected to your Solaris box.

You can install and boot Gentoo on a separate partition. You must be EXTREMELY CAREFUL with automatic assignment of device names if you do not use partition labels in your fstab file and mount with "mount -L .....".

Good Luck

chrisrobinson · n00b Joined: 02 Sep 2016 Posts: 4 Location: Cambridge, MA

C5Ace,

Your reply is very informative and hopeful and I thank you for it. When I try to mount a USB while running the Gentoo desktop, I get the message that it is not possible since I don't have root privileges.
I don't know how to access root either with su or sudo on the desktop version. However, I realize that booting Gentoo from a USB, rather than from a live CD, may be different and allow me to get access
my Solaris OS.
Your instructions about installing Gentoo on a separate partition are also very helpful. I really don't see why this is not possible, especially since my manual says that other Linux and Windows partitions
are possible. However, I spoke with a techie about cloning my hard disk and he strongly discouraged me from writing any thing else to it.
I am quite surprised that no one from the Solaris community has offered any real help with this. My manual, the Open Solaris Bible does address the issue, but their solution: bootadm upadate-archive
did not fix it. In fact, I am just about to contact one of the book's authors directly for more help.
Right now the most promising path is this: take out the hard disk and have it cloned, insert a new drive, probably an SSD, install a new OS, probably Gentoo, and finally install an image of the original
disk. Any ideas about any of this are most welcome.

Buffoon · Veteran Joined: 17 Jun 2015 Posts: 1369 Location: EU or US

I fail to see how installed Gentoo is better than SystemRescueCD on USB for your purpose.

C5ace · Posted: Sun Sep 04, 2016 10:55 am Post subject:

NeddySeagoon · Posted: Sun Sep 04, 2016 11:12 am Post subject:

chrisrobinson,

If the data structures on your HDD are damaged in any way, do not attempt any operations that will change the data.
Anything can happen. You first step is to make disk image(s) and validate them, so that you can be sure to recover to where you were when your data recovery makes things worse, not better.

Do not expect to perform in place data recovery.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

chrisrobinson · n00b Joined: 02 Sep 2016 Posts: 4 Location: Cambridge, MA

If I select the GRUB option to boot the Gentoo Live CD from the hard disk will that overwrite any existing data?
If not, can I then use it to read files on a Solaris partition?

NeddySeagoon · Posted: Sun Sep 04, 2016 7:40 pm Post subject:

chrisrobinson,

I can't parse your question. You can't boot the Gentoo Live CD from the hard disk.

If the Gentoo live CD has the partition and filesystem support that you need, it can read Solaris partitions.
I don't know what Solaris uses.

The liveCD is just a set of tools. It will do nothing to your HDD unless you ask it.
SystemRescueCD is much the same but it has an optional GUI and much wider hardware support.
Neither of these tool kits provide the things you need to build more software.
For that, you need the Gentoo LiveDVD on a USB stick with its persistent feature enabled.
That gives you a fully featured Gentoo evaluation system that remembers your changes.
Updating the kernel could be tricky though.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.