Re: ext4 filesystem not recognised on new LVM volume

[John Lane]

On 17/12/14 17:46, Andrei Borzenkov wrote:
> В Wed, 17 Dec 2014 15:42:02 +0000
> John Lane <address@hidden> пишет:
>
>> On 17/12/14 15:03, Andrei Borzenkov wrote:
>>> On Wed, Dec 17, 2014 at 5:41 PM, John Lane <address@hidden> wrote:
>>>> On 15/12/14 13:28, Andrei Borzenkov wrote:
>>>>> On Mon, Dec 15, 2014 at 3:51 PM, John Lane <address@hidden> wrote:
>>>>>> On 15/12/14 12:27, John Lane wrote:
>>>>>>> I'm going to wipe the disk and start over and see if I can reproduce it.
>>>>>>>
>>>>>>>
>>>>>> Ok, I believe this is a 2TiB issue.
>>>>>>
>>>>>> I just wiped the disk, created a new PV on it and created 3 LVs on the 
>>>>>> PV.
>>>>>>
>>>>>> LV1 5GiB ext4
>>>>>> LV2 2TiB ext4
>>>>>> LV3 5GiB ext4
>>>>>>
>>>>>> Grub can read LV1 and LV2 but not LV3.
>>>>>>
>>>>> And if you create physical partitions of the same size?
>>>>>
>>>> Sorry for delay in responding but I needed to use the disk as a transit
>>>> drive.
>>>>
>>>> Anyway, I just created a new GPT with partition 1=5G, 2=2T and 3=5G.
>>>> I wrote new ext4 filesystems to each of them.
>>>>
>>>> grub can read partitions 1 and 2 but not partition 3.
>>>>
>>> I suspect it hits BIOS 2TB limit. If you have AHCI compatible
>>> controller, you could try command "nativedisk" which attempts to
>>> switch from BIOS to native AHCI. No guarantee that it will work; but
>>> if it will, it should lift 2TB limit. Better try with git master.
>> that works. I never knew about "nativedisk".
> It is more of a debug tool. Note that AHCI driver has its downside -
> e.g. it is impossible to chainload anything, because it relies on BIOS
> interface and we cannot go back to BIOS after AHCI driver run. And of
> course it gets far less test coverage. If you are OK with it you can
> build core.img to use native drivers:
>
> grub-install --disk-module=native ...
>
I'll keep that in mind, but the scenario won't likely happen in real use as
the root volume will (should?) be in the first 2TiB anyway.
>> grub> ls (ata0,3)/
>>
>> Also works with LVM.
> Yes, sure. But it is still fishy; I wonder what happens here. Is it 4K
> disk by any chance?
>
Yes, I've been testing with a 4TB ST4000VN000 which has 4k sectors.
>>>> I am doing
>>>>
>>>> grub> ls (hd1,1)/
>>>>
>>>> etc.
>>>>