[gentoo-user] GPT newbee needs some help

[gentoo-user] GPT newbee needs some help

[Helmut Jarausch]

Hi,

having formatted dozens of hard disks with fdisk, I'm lost with GPT  
partitioning.

My new drive was preformatted for Windows, so I first deleted the two  
partitions which were present.
Unfortunately I've used fdisk.
Then I tried to use gdisk. I have created 4 partitions, the first of  
which started at sector 2048.
I wrote the partition table back to disk, synced and remove the  
(portable USB-) disk from my system.
Then I connected it again.
Now my problem is, that my system only shows  /dev/sde and /dev/sde1  
whereas I expected to see
/dev/sde1 ,.../dev/sde4 .

So, what did I miss?

Many thanks for your help,
Helmut

Re: [gentoo-user] GPT newbee needs some help

[Mick]

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On Thursday 21 Jul 2016 19:36:51 Helmut Jarausch wrote:
> Hi,
> 
> having formatted dozens of hard disks with fdisk, I'm lost with GPT
> partitioning.
> 
> My new drive was preformatted for Windows, so I first deleted the two
> partitions which were present.
> Unfortunately I've used fdisk.
> Then I tried to use gdisk. I have created 4 partitions, the first of
> which started at sector 2048.
> I wrote the partition table back to disk, synced and remove the
> (portable USB-) disk from my system.
> Then I connected it again.
> Now my problem is, that my system only shows  /dev/sde and /dev/sde1
> whereas I expected to see
> /dev/sde1 ,.../dev/sde4 .
> 
> So, what did I miss?
> 
> Many thanks for your help,
> Helmut

Are you sure you wrote the partition to disk?  If you pressed "q" to quit the 
application without first pressing "w" to write your changes to disk your 
entries would be lost.

From what you state you have a disk /dev/sde, on which you have created/saved 
only one partition, /dev/sde1.

-- 
Regards,
Mick

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Re: [gentoo-user] GPT newbee needs some help

[R0b0t1]

On Thu, Jul 21, 2016 at 12:36 PM, Helmut Jarausch <jarausch@skynet.be> wrote:
> So, what did I miss?
>
> Many thanks for your help,
> Helmut

The disk may be failing. If it isn't, try zeroing the start of it
and/or repartitioning it. The two programs are essentially the same.

Re: [gentoo-user] GPT newbee needs some help

[covici]

R0b0t1 <r030t1@gmail.com> wrote:

> On Thu, Jul 21, 2016 at 12:36 PM, Helmut Jarausch <jarausch@skynet.be> wrote:
> > So, what did I miss?
> >
> > Many thanks for your help,
> > Helmut
> 
> The disk may be failing. If it isn't, try zeroing the start of it
> and/or repartitioning it. The two programs are essentially the same.
> 

What happens if you use gdisk again and use the p command?

-- 
Your life is like a penny.  You're going to lose it.  The question is:
How do
you spend it?

         John Covici
         covici@ccs.covici.com

[gentoo-user] Re: GPT newbee needs some help

[James]

Helmut Jarausch <jarausch <at> skynet.be> writes:

> 
> Hi,
> 
> having formatted dozens of hard disks with fdisk, I'm lost with GPT  
> partitioning.
> 
> My new drive was preformatted for Windows, so I first deleted the two  
> partitions which were present.
> Unfortunately I've used fdisk.
> Then I tried to use gdisk. I have created 4 partitions, the first of  
> which started at sector 2048.
> I wrote the partition table back to disk, synced and remove the  
> (portable USB-) disk from my system.
> Then I connected it again.
> Now my problem is, that my system only shows  /dev/sde and /dev/sde1  
> whereas I expected to see
> /dev/sde1 ,.../dev/sde4 .

First determine if the motherboards is a Bios or EFI variety. 

Then, decide which bootloader you are going to use:: grub(legacy) grub2,
lilo, gummi, EFI, etc etc? Last, how many different distros will you
ultimately be booting off that disk.

Then with that data, decide which formatting tool to use. (Others will
disagree with this logical progression, which is good as long as they
refine there reasons, explicitly.)

hth,
James

Re: [gentoo-user] Re: GPT newbee needs some help

[Neil Bothwick]

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On Thu, 21 Jul 2016 20:11:00 +0000 (UTC), James wrote:

> First determine if the motherboards is a Bios or EFI variety. 
> 
> Then, decide which bootloader you are going to use:: grub(legacy) grub2,
> lilo, gummi, EFI, etc etc? Last, how many different distros will you
> ultimately be booting off that disk.
> 
> Then with that data, decide which formatting tool to use. (Others will
> disagree with this logical progression, which is good as long as they
> refine there reasons, explicitly.)

I agree up until the last paragraph. You can use gdisk and a GPT whether
you are using BIO or EFI. The difference is in your first partition. For
EFI it must be type EF00 and formatted with FAT. For BIOS booting you
need to start the disk with a small BIOS compatibility partition of type
EF02. This is 1M here and you don't format or use it, it just has to be
there.

Regarding the apparent lack of partitions, what does gdisk -l /dev/sde
show?


-- 
Neil Bothwick

During a raid on a local chemist's shop, 2000 Viagra tablets were stolen
Police are looking for hardened criminals!

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Re: [gentoo-user] Re: GPT newbee needs some help

[covici]

Neil Bothwick <neil@digimed.co.uk> wrote:

> On Thu, 21 Jul 2016 20:11:00 +0000 (UTC), James wrote:
> 
> > First determine if the motherboards is a Bios or EFI variety. 
> > 
> > Then, decide which bootloader you are going to use:: grub(legacy) grub2,
> > lilo, gummi, EFI, etc etc? Last, how many different distros will you
> > ultimately be booting off that disk.
> > 
> > Then with that data, decide which formatting tool to use. (Others will
> > disagree with this logical progression, which is good as long as they
> > refine there reasons, explicitly.)
> 
> I agree up until the last paragraph. You can use gdisk and a GPT whether
> you are using BIO or EFI. The difference is in your first partition. For
> EFI it must be type EF00 and formatted with FAT. For BIOS booting you
> need to start the disk with a small BIOS compatibility partition of type
> EF02. This is 1M here and you don't format or use it, it just has to be
> there.
> 
> Regarding the apparent lack of partitions, what does gdisk -l /dev/sde
> show?

And if its not your boot disk, you can still use gpt with no
restrictions which is what I have been doing.

-- 
Your life is like a penny.  You're going to lose it.  The question is:
How do
you spend it?

         John Covici
         covici@ccs.covici.com

[gentoo-user] Re: GPT newbee needs some help

[James]

Neil Bothwick <neil <at> digimed.co.uk> writes:


> > First determine if the motherboards is a Bios or EFI variety. 
> > Then, decide which bootloader you are going to use:: grub(legacy) grub2,
> > lilo, gummi, EFI, etc etc? Last, how many different distros will you
> > ultimately be booting off that disk.

> > Then with that data, decide which formatting tool to use. (Others will
> > disagree with this logical progression, which is good as long as they
> > refine there reasons, explicitly.)

> I agree up until the last paragraph. You can use gdisk and a GPT whether
> you are using BIO or EFI. The difference is in your first partition. For
> EFI it must be type EF00 and formatted with FAT. For BIOS booting you
> need to start the disk with a small BIOS compatibility partition of type
> EF02. This is 1M here and you don't format or use it, it just has to be
> there.

I do not diagree what you are stating. I'll try it again. My logic is
hopefully sound, but might not appeal to everyone. It's what I'm working on
for my cluster/node reconfiguration tool which will eventually boot
embedded, many different arches and also use a variety of (i)PXE style node
wake-ups and fast boots with images served from servers. Hence the need for
one generic HD partition scheme:: (no raid decision tree) so drives and
systems can be moved around into a variety of test configurations as easily
as possible.

1. Is the disk a boot disk. (ignore additional disks for now. Most are 2G
sata drives.

2. (assuming yes)  Which distros will be booting off that disk.

3. Determine if the motherboards is a Bios or EFI variety.

4. Select a bootloader. (grub-1 grub-2 etc.

5. Specify the (example:boot/root/swap) partition scheme according to
previous data, ignoring other optional partitions for this example.

6. Select the partition tool.

Note:: a generic default (generic) partition scheme, shown below will work
for both Bios and EFI systems, so if a HD is moved between different mobos,
all else being same it should not have to be reformatted.

<what would that default generic partition scheme look like for just
boot, root and swap that works on both mbr(bios) and efi motherboards?>

Hopefully this makes sense, as the basis of a collection of systems to
test a variety of cluster architectures, DFS and clusters codes, on
identical  hardware to validate performance comparison....


James

Re: [gentoo-user] Re: GPT newbee needs some help

[Neil Bothwick]

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On Thu, 21 Jul 2016 22:01:29 +0000 (UTC), James wrote:

> <what would that default generic partition scheme look like for just
> boot, root and swap that works on both mbr(bios) and efi motherboards?>

I'm not sure it can be done. BIOS needs an EF00 partition at the start.
EFI calls for an EF00 partition, which is recommended at the start but I
don't think it's compulsory that it is there. I have heard of people
using sda2 as the ESP where sda1 is a Windows rescue partition. So you
may get away with

p1 EF02 partition
p2 EF00 partition, formatted as FAT and mounted at /boot
root and swap partitions as you see fit.

You could try it and see, but I'm not sure it could be guaranteed to work
on all EFI hardware, although it should work on all BIOS hardware.


-- 
Neil Bothwick

Mouse: (n.) an input device used by management to force computer users to
       keep at least a part of their desks clean.

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Re: [gentoo-user] Re: GPT newbee needs some help

[Helmut Jarausch]

Thanks to all of you who have tried to help.
Unfortunately, I am still lost.

I just want to run Gentoo on my system, and the new drive is just for  
backup, i.e. it needn't be bootable.

I have zeroed the first 8 MB and then I used gdisk
gdisk still notes that there is a backup GPT. I opted to created a new  
blank GPT.
Then I created 4 partitions.
I have used the w(rite) command before exiting gdisk.
Starting gdisk again, it shows the 4 partitions.
But, after a 'sync' command I detached and re-attached the drive and I  
get partially strange
output from dmesg :


[ 2225.690410] usb 9-1: New USB device found, idVendor=0bc2,  
idProduct=ab34
[ 2225.690418] usb 9-1: New USB device strings: Mfr=2, Product=3,  
SerialNumber=1
[ 2225.690423] usb 9-1: Product: Backup+  Desk
[ 2225.690426] usb 9-1: Manufacturer: Seagate
[ 2225.690430] usb 9-1: SerialNumber: NA7EV58E
[ 2225.692007] usb-storage 9-1:1.0: USB Mass Storage device detected
[ 2225.692167] scsi host8: usb-storage 9-1:1.0
[ 2226.693728] scsi 8:0:0:0: Direct-Access     Seagate  Backup+   
Desk    040B PQ: 0 ANSI: 6
[ 2226.694322] sd 8:0:0:0: Attached scsi generic sg5 type 0
[ 2226.696829] sd 8:0:0:0: [sde] Spinning up disk...
16 # dmesg | tail
[ 2240.741282] sd 8:0:0:0: [sde] Very big device. Trying to use READ  
CAPACITY(16).
[ 2240.741400] sd 8:0:0:0: [sde] 9767541167 512-byte logical blocks:  
(5.00 TB/4.55 TiB)
[ 2240.741405] sd 8:0:0:0: [sde] 2048-byte physical blocks
[ 2240.791085] sd 8:0:0:0: [sde] Write Protect is off
[ 2240.791096] sd 8:0:0:0: [sde] Mode Sense: 4f 00 00 00
[ 2240.791853] sd 8:0:0:0: [sde] Write cache: enabled, read cache:  
enabled, doesn't support DPO or FUA
[ 2240.792897] sd 8:0:0:0: [sde] Very big device. Trying to use READ  
CAPACITY(16).
[ 2240.832400]  sde: sde1
[ 2240.832943] sd 8:0:0:0: [sde] Very big device. Trying to use READ  
CAPACITY(16).
[ 2240.835581] sd 8:0:0:0: [sde] Attached SCSI disk
17 # dmesg | tail
[ 2240.741282] sd 8:0:0:0: [sde] Very big device. Trying to use READ  
CAPACITY(16).
[ 2240.741400] sd 8:0:0:0: [sde] 9767541167 512-byte logical blocks:  
(5.00 TB/4.55 TiB)
[ 2240.741405] sd 8:0:0:0: [sde] 2048-byte physical blocks
[ 2240.791085] sd 8:0:0:0: [sde] Write Protect is off
[ 2240.791096] sd 8:0:0:0: [sde] Mode Sense: 4f 00 00 00
[ 2240.791853] sd 8:0:0:0: [sde] Write cache: enabled, read cache:  
enabled, doesn't support DPO or FUA
[ 2240.792897] sd 8:0:0:0: [sde] Very big device. Trying to use READ  
CAPACITY(16).
[ 2240.832400]  sde: sde1
[ 2240.832943] sd 8:0:0:0: [sde] Very big device. Trying to use READ  
CAPACITY(16).
[ 2240.835581] sd 8:0:0:0: [sde] Attached SCSI disk

and only  /dev/sde and /dev/sde1 are visible.

Where are the other partitions - or am I missing a kernel option.
That is my first drive bigger than 3 TB.

Many thanks for your help,
Helmut

Re: [gentoo-user] Re: GPT newbee needs some help

[Neil Bothwick]

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On Fri, 22 Jul 2016 10:04:58 +0200, Helmut Jarausch wrote:

> I have zeroed the first 8 MB and then I used gdisk
> gdisk still notes that there is a backup GPT. I opted to created a new  
> blank GPT.
> Then I created 4 partitions.
> I have used the w(rite) command before exiting gdisk.
> Starting gdisk again, it shows the 4 partitions.

You still haven't showed us the output from gdisk -l /dev/sde


-- 
Neil Bothwick

I'm writing a book. I've got the page numbers done.

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Re: [gentoo-user] Re: GPT newbee needs some help

[Helmut Jarausch]

On 07/22/2016 10:28:35 AM, Neil Bothwick wrote:
> On Fri, 22 Jul 2016 10:04:58 +0200, Helmut Jarausch wrote:
> 
> > I have zeroed the first 8 MB and then I used gdisk
> > gdisk still notes that there is a backup GPT. I opted to created a  
> new
> > blank GPT.
> > Then I created 4 partitions.
> > I have used the w(rite) command before exiting gdisk.
> > Starting gdisk again, it shows the 4 partitions.
> 
> You still haven't showed us the output from gdisk -l /dev/sde

OK, here it is:

gdisk -l /dev/sde
GPT fdisk (gdisk) version 1.0.1

Partition table scan:
   MBR: protective
   BSD: not present
   APM: not present
   GPT: present

Found valid GPT with protective MBR; using GPT.
Disk /dev/sde: 9767541167 sectors, 4.5 TiB
Logical sector size: 512 bytes
Disk identifier (GUID): A072CFE0-0651-441C-8BA2-8527623BA142
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 9767541133
Partitions will be aligned on 2048-sector boundaries
Total free space is 2014 sectors (1007.0 KiB)

Number  Start (sector)    End (sector)  Size       Code  Name
    1            2048      3145730047   1.5 TiB     8300  Linux  
filesystem
    2      3145730048      5293213695   1024.0 GiB  8300  Linux  
filesystem
    3      5293213696      7440697343   1024.0 GiB  8300  Linux  
filesystem
    4      7440697344      9767541133   1.1 TiB     8300  Linux  
filesystem

Re: [gentoo-user] Re: GPT newbee needs some help

[Dmitry Bogun]

Look like you don't have gpt support in kernel.

Post output from command "gunzip -c /proc/config.gz | grep '_PARTITION\>'"

> On Jul 22, 2016, at 11:37 AM, Helmut Jarausch <jarausch@skynet.be> wrote:
> 
> On 07/22/2016 10:28:35 AM, Neil Bothwick wrote:
>> On Fri, 22 Jul 2016 10:04:58 +0200, Helmut Jarausch wrote:
>> > I have zeroed the first 8 MB and then I used gdisk
>> > gdisk still notes that there is a backup GPT. I opted to created a new
>> > blank GPT.
>> > Then I created 4 partitions.
>> > I have used the w(rite) command before exiting gdisk.
>> > Starting gdisk again, it shows the 4 partitions.
>> You still haven't showed us the output from gdisk -l /dev/sde
> 
> OK, here it is:
> 
> gdisk -l /dev/sde
> GPT fdisk (gdisk) version 1.0.1
> 
> Partition table scan:
>  MBR: protective
>  BSD: not present
>  APM: not present
>  GPT: present
> 
> Found valid GPT with protective MBR; using GPT.
> Disk /dev/sde: 9767541167 sectors, 4.5 TiB
> Logical sector size: 512 bytes
> Disk identifier (GUID): A072CFE0-0651-441C-8BA2-8527623BA142
> Partition table holds up to 128 entries
> First usable sector is 34, last usable sector is 9767541133
> Partitions will be aligned on 2048-sector boundaries
> Total free space is 2014 sectors (1007.0 KiB)
> 
> Number  Start (sector)    End (sector)  Size       Code  Name
>   1            2048      3145730047   1.5 TiB     8300  Linux filesystem
>   2      3145730048      5293213695   1024.0 GiB  8300  Linux filesystem
>   3      5293213696      7440697343   1024.0 GiB  8300  Linux filesystem
>   4      7440697344      9767541133   1.1 TiB     8300  Linux filesystem
> 

Re: [gentoo-user] Re: GPT newbee needs some help

[Helmut Jarausch]

On 07/22/2016 10:49:35 AM, Dmitry Bogun wrote:
> Look like you don't have gpt support in kernel.

Many thanks Dmitry,
that was the problem.

Since I have a somewhat older mother board with no UEFI support, I  
couldn't image why I need the
EFI GUID Partition support
setting for my kernel.
I have set this now and the new kernel does see my partitions.

Many thanks again,
Helmut

Re: [gentoo-user] Re: GPT newbee needs some help

[John Runyon]

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