[Solved] Moving a system to external USB drive

creaker · l33t Joined: 14 Jul 2012 Posts: 651

Hi!
Trying to move my current system to external USB drive.
System was packed in stage4 recently and now I've extracted it to external hdd.
The system itself is OK, I attached hdd to sata port directly and successfully booted.
The thing is I can't boot it over USB, when hdd sits in enclosure. During startup I'm getting it hanging for about a 9 seconds (at 2.3436) and it completely stops at this screen:
http://i.imgur.com/KFOW79R.jpg
What may cause a stop?

Thanks.

eccerr0r · Posted: Sun Oct 05, 2014 5:55 pm Post subject:

Are you using initramfs?

Something similar happens to me when my initramfs didn't allow enough time to detect the USB disks which takes a while to enumerate, the mount fails, and it then drops to the emergency shell (so if you press enter you get the busybox prompt in initramfs).

I also have a similar external case that's eSATA+USB, the USB requires the root wait delay where the eSATA does not.
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creaker · l33t Joined: 14 Jul 2012 Posts: 651

Thanks for reply.
I do not use initramfs. Regarding a delay for root I'm aware of it. Grub menu has an rootwait option to wait for getting device ready:

NeddySeagoon · Posted: Sun Oct 05, 2014 8:15 pm Post subject:

creaker,

You will need all the USB support for your USB hubs built in along with USB storage.
Its also in the initrd but that doesn't help as USB is not nornally started until after root is mounted.
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NeddySeagoon

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

creaker · l33t Joined: 14 Jul 2012 Posts: 651

NeddySeagoon
OK, I'm going to build kernel with genkernel. Anyway this installation tends to be liveUSB, so it maybe a good reason to run genkernel.

creaker · l33t Joined: 14 Jul 2012 Posts: 651

Yes it helped, genkernel built kernel with tons of modules, on of them seems was missed. System boots with some minor issues: kernel refuses to mount root partition by UUID (though I have initramfs built as well) and invites me to type correct root device. Hitting "Enter" causes autodetection and mounting "real_root=/dev/sdc1". The rest of boot process going smoothly. I checked UUID twice.
How do I force mounting by UUID?

DONAHUE · Posted: Mon Oct 06, 2014 2:39 am Post subject:

try adding rootdelay=30 to the kernel commandline. 30 should be excessive, if it works you can reduce it, if it doesn't .....
the usb drive may need some time to "settle" before root can mount
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creaker · l33t Joined: 14 Jul 2012 Posts: 651

Tried it, doesn't help. Replacing boot parameter to real_root doesn't help as well.
Seemes it's some kind of eudev issue. When boot stopped I went to shell to check /dev. ls doesn't show /dev/disk there. I think it should be there at that moment.

DONAHUE · Posted: Mon Oct 06, 2014 7:17 am Post subject:

maybe config_mount_devtmpfs in kernel?
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creaker · l33t Joined: 14 Jul 2012 Posts: 651

How do I set CONFIG_DEVTMPFS_MOUNT? I tried to set it to "y", but genkernel just drops .config and starts with template that hasn't this option set.
In addition tried rootfstype boot option, tried to switch to real_root=/dev/sdc1, to real_root=LABEL=USB, but still no luck.
Have to try to build kernel with make.

Roman_Gruber · Posted: Mon Oct 06, 2014 8:04 am Post subject:

creaker · l33t Joined: 14 Jul 2012 Posts: 651

Built it with make.

NeddySeagoon · Posted: Mon Oct 06, 2014 4:56 pm Post subject:

creaker,

Mounting by UUID works only if the kernel can see the HDD. None of /dev /dev/disk /dev/disk/by-label are required.
Think about it. /dev is on root so it cannot be accessed until after root is mounted.
I have a static /, so /dev/disk /dev/disk/by-label and so on never exist but mounting by UUID still works.

The USB HCD options and USB starage must be built in an root is normally mounted before USB is started.
Thats an issue for root on USB.
_________________
Regards,

NeddySeagoon

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

creaker · l33t Joined: 14 Jul 2012 Posts: 651

NeddySeagoon

thanks for hint, it was really hcd issue, selected them both (ehci_hcd & xhci_hcd) as built-in, it solved a problem.

creaker · l33t Joined: 14 Jul 2012 Posts: 651

Next step is getting it bootable on other machines.
Two questions:
1. Is it enough to remove -march=native option from make.conf (and rebuild system) to get code with generic instructions set only? In order to get it working with other CPUs (preventing "illegal instructions" error).
2. Is it enough to specify few video drivers (e.g. VIDEO_CARDS="nouveau radeon vesa via") on system rebuild? Will appropriate module being loaded/used depending on current video card? Or should it be selected/switched by script?

Roman_Gruber · Posted: Tue Oct 07, 2014 5:20 pm Post subject:

NeddySeagoon · Posted: Tue Oct 07, 2014 5:45 pm Post subject:

creaker,

Use -mtune=generic and leave -march unset for 64bit.
Don't forget to rebuild the kernel too.

32 bit is a bit more difficult and it depends how far back you want to go anu if you need the toolchian to work on the old hardware.

eg. a K6-2 is i586, so to get back there on a i686 install, you need -march=pentium.
However your CHOST, which is used to build the toolchain will still be i686, so it won't run on anything less.
You can change the CHOST on a 32 bit install but thun you are doing a stage1.
Again, don't forget the kernel
_________________
Regards,

NeddySeagoon

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

creaker · l33t Joined: 14 Jul 2012 Posts: 651

Well, I've booted Gentoo LiveDVD, CFLAGS and CXXFLAGS are set to "-O2 -pipe" there. Seemingly it will be correct to have

NeddySeagoon · Posted: Tue Oct 07, 2014 7:21 pm Post subject:

creaker,

Look in make menuconf. I think genkernel always uses generic in the CPU selection.
--menuconf is a genkernel command line option so you can look before the build starts.

There may only be a single - there. Try genkernel --help
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Regards,

NeddySeagoon

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

creaker · l33t Joined: 14 Jul 2012 Posts: 651

make menuconfig upon .config that was created by genkernel shows "Generic-x86-64" for "Processor type and family" option:

NeddySeagoon · Posted: Tue Oct 07, 2014 8:26 pm Post subject:

creaker,

The kernel is already generic then.
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Regards,

NeddySeagoon

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

creaker · l33t Joined: 14 Jul 2012 Posts: 651

Yes, I can boot with it till login, but failed to log in due to illegal instructions error. Have to rebuild entire the system (excluding kernel), but emerge refuses to do it.

NeddySeagoon · Posted: Tue Oct 07, 2014 9:01 pm Post subject:

creaker,

You need to do the build on a system that understands the illegal instructions.
You can't move the HDD to another system, then do the build. Well, it might work, it might not.
_________________
Regards,

NeddySeagoon

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

creaker · l33t Joined: 14 Jul 2012 Posts: 651

creaker · l33t Joined: 14 Jul 2012 Posts: 651

Well, I rebuilt a system wth generic CPU options and tested it for a few day at different machines (core i3 3210, core i3 2120, core i5 650, core 2 duo E8500, amd Phenom FX 9650, Athlon 64 X2 4200). All seems good.
Right now I have this setup at usb HDD. But I'd like to be able to put it to any occasional usb pen drive. In fact system works at any pen drive, but the speed is extremely low. Starting firefox takes half of minute, dolphin starts in 15 secs and so on. It isn't a pen drive issue, I tried few stick with read performance at range 17-20 Mb/sec. One of these sticks hosted remastered Debain in past that was amazingly fast. So I decided to put /usr into RAM disk, but failed - ran out of memory. I stripped /usr as much as I can (down to 1,9Gb), but still can't fit it to 4Gb of RAM. The last attempt I did was a putting only /usr/lib into RAM. I can fit into 4Gb, but can't understand why 1,0Gb of /usr/lib occupies 3Gb of RAM?