Re: lvm module can't see USB disks' volume group

[Alexandre Oliva]

On Feb  1, 2017, Andrei Borzenkov <address@hidden> wrote:

> 31.01.2017 22:27, Alexandre Oliva пишет:
>> 
>> 
>> Note: I haven't yet determined that it's the USBness of the disks that's
>> a factor; it might be disk size, though I find that unlikely.  So far,
>> I've only converted some sub-TB disks to LVM.  The new USB disks that I
>> set up with LVM are 5TB with 512b logical sectors; I've got another
>> slightly older 5TB non-USB disk that I intend to convert over the next
>> few days, and other smaller but still few-TB-sized disks, some plain
>> SATA, some in USB3 enclosures that make the disks seem to support only
>> 4KiB sectors, and so I may shortly know whether GRUB has issues with big
>> PVs or USB disks. 

> GRUB itself should not, but BIOS support for 4K disks is pretty flaky.

I think I may have had trouble with the 4K enclosures before, but I
haven't got to them yet.  The problems I reported in my earlier email
involved newer enclosures that exported 512b logical sectors.

> If you have possibility to attach serial console (or otherwise record
> grub output) we may try to debug it.

I don't have serial ports, but I can take pictures of the screen and
type stuff in afterwards, if that helps.  There hasn't been much output
that could be of use for debugging, though.  Anyway, if you have any
ideas of what I should try to get useful info out of grub to enable LVM
to work out of USB enclosures (512b and, with luck, the older 4K ones
too ;-) with partitions and hopefully without them, please let me know,
and I'll get the output back to you eventually.

Thanks!

-- 
Alexandre Oliva, freedom fighter    http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/   FSF Latin America board member
Free Software Evangelist|Red Hat Brasil GNU Toolchain Engineer