SSD /root and HDD /home issues

[Johnius]

Hello all,

Thank you for your time. I have a 256gb Samsung SSD that I want to run Kubuntu from and a 1tb HDD that I want to use as my data partition for a dual-boot. I'd like to assign the /home directory during install as I think I should be able to do so. I can see the HDD in kParted and with fdisk -l. But when I run the Kubuntu installer, only the SSD shows up. Maybe it's not worth my time fussing with it and just remap /home after install?

Thanks,
Johnius

[oldfred]

Post this from live installer's terminal:
sudo parted -l
sudo gdisk -l /dev/sdb

Is system UEFI? And both drives gpt partitioned?

On my 256GB SSD, I have multiple / (root) partitions, as well as more / on HDD for tests or just experiments. So I use a /mnt/data partition. Then settings in /home can be different between installs, but all data is same.

[Johnius]

Model: ATA Samsung SSD 850 (scsi)
Disk /dev/sda: 250GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:

Number Start End Size Type File system Flags
1 1049kB 230GB 230GB primary ntfs boot
2 230GB 250GB 20.1GB primary ext4


Model: ATA WDC WD10EALX-009 (scsi)
Disk /dev/sdb: 1000GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:

Number Start End Size Type File system Flags
1 1049kB 1050MB 1049MB primary linux-swap(v1)
2 1050MB 1000GB 999GB primary ntfs


Model: (scsi)
Disk /dev/sdc: 4010MB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:

Number Start End Size Type File system Flags
1 1049kB 4006MB 4005MB primary fat32 boot


and



GPT fdisk (gdisk) version 1.0.1

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


************************************************** *************
Found invalid GPT and valid MBR; converting MBR to GPT format
in memory.
************************************************** *************

Disk /dev/sdb: 1953525168 sectors, 931.5 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): 0B670CA5-C5B2-4372-8228-3C86BB920BD4
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 1953525134
Partitions will be aligned on 2048-sector boundaries
Total free space is 7533 sectors (3.7 MiB)

Number Start (sector) End (sector) Size Code Name
1 2048 2050047 1000.0 MiB 8200 Linux swap
2 2050048 1953519615 930.5 GiB 0700 Microsoft basic data


I'm on a non-UEFI BIOS. Running in ACHI mode. I can see all of the drives everywhere they should be outside of the installer. Once in the installer, sdb and sdc disappear.

[oldfred]

Gdisk sees this and that is a problem, Linux tools see both and do not know what to do:
Found invalid GPT and valid MBR

If drive was gpt, and you used Windows to convert to MBR, then Windows does it incorrectly.
You can use fixparts or gdisk to fix the issue.

FixParts is the easiest way to remove the stray GPT data. GPT fdisk (gdisk or sgdisk) can do it, but the procedure's a bit more involved.
http://www.rodsbooks.com/fixparts/
sudo fixparts /dev/sdb

Or you can convert to gpt. But be sure to have good backups either way.
Converting from MBR to gpt:
http://ubuntuforums.org/showthread.php?t=1454252

Use Windows to shrink the NTFS partition and reboot into Windows and run chkdsk on that partition. Then manually partition in advance or partition as part of install with Something Else. With existing partitions and two drives do not use an auto install option.

GPT Advantages (older 2010 but still valid) see post#2 by srs5694:
http://ubuntuforums.org/showthread.php?t=1457901
https://wiki.archlinux.org/index.php/GUID_Partition_Table#Advantages_of_GPT
http://en.wikipedia.org/wiki/Unified_Extensible_Firmware_Interface

[Johnius]

Thank you! I will give that a try. Probably best to convert to GPT.

[oldfred]

Only if you may later want to install Windows in BIOS boot mode, may you want to stay with MBR.
Windows only boots in BIOS mode from MBR partitioned drives.
Both Windows & Ubuntu boot from gpt with UEFI.
And if you add a bios_grub partition to a gpt partitioned drive, you can boot Ubuntu in BIOS mode.

I started converting all new or reformatted drives to gpt back in 2010. And when Windows required PCs to use UEFI with Windows 8, 5 years ago, I knew eventually I would get a new UEFI system, so started adding both the ESP - efi system partition ( for future use) and a bios_grub partition for my older BIOS based system as first two partitions on every drive.
Now I have UEFI but still add a bios_grub partition. Not sure why as I doubt I will convert drive back to BIOS boot,but it is only 1MB.

Oldfred's current partitions Dec 2015, still pretty current other than Ubuntu versions updated to something newer.
http://ubuntuforums.org/showthread.php?t=2305833&p=13404413#post13404413