OK, I have an HP laptop and an external USB drive. the Laptop dual boots into Windows 10 and Linux Mint, I'd like to allocat half the external drive to Windows and half to Linux.
The Windows bit has been easy - created an NTFS partition on the drive using only half the apace available

But when I go into Linux Hard Disk manager utility it shows the drive (/dev/sdb) but it also says "No medium" in the volumes section of the window, and none of the menu alternatives (format partition, edit partition etc) show as available. The only one showing up is "Edit Mount options"

fdisk -l shows all the entries for /dev/sda but there's no mention of /dev/sdb

Help! What am I missing? I 'm sure it's pretty simple. I'm a noob to Linux, so any commands etc please spell them out.

Thanks..
Chris

Try gparted. You have to use that as root or using the sudo command modifier.

Gparted will allow you to see your entire disk and then allow you to create a Linux partition on it, and format it, as well as name it.

Thanks so far - I downloaded Gparted but it is not even seeing the device - the disk utility saw it and listed it as /dev/sdb, but wouldn't let me do anything. gparted only sees /dev/sda...

gparted is included with Linux Mint.

Under the main menu, titled GParted you can refresh the devices, and also see the list of devices. You're saying you don't see the drive there?

Yep, just ran a refresh, and only /dev/sda.

What does:(Lowercase L)

Give you?

that gives:

Disk /dev/sda: 238.5 GiB, 256060514304 bytes, 500118192 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: gpt
Disk identifier: A6ED5E89-0BDE-4A33-8467-9FB811578E3B

Device Start End Sectors Size Type
/dev/sda1 2048 534527 532480 260M EFI System
/dev/sda2 534528 567295 32768 16M Microsoft reserved
/dev/sda3 567296 388665727 388098432 185.1G Microsoft basic data
/dev/sda4 467632128 469639167 2007040 980M Windows recovery environment
/dev/sda5 469639168 500105215 30466048 14.5G Microsoft basic data
/dev/sda6 388667392 451024895 62357504 29.8G Linux filesystem
/dev/sda7 451024896 467632127 16607232 7.9G Linux swap

Partition table entries are not in disk order.


FYI, ls /dev/ gives the following:

chris@chris-HP-Pavilion-Laptop-14-bf1xx ~ $ ls /dev/ |grep sd
sda
sda1
sda2
sda3
sda4
sda5
sda6
sda7
sdb

So that suggests sdb is in there somewhere...

Your /dev directory can have any number of /dev/sd[abcdefghijkl] letters. It does not mean you have a physical drive just because there is a filename.

From all I can see you have one drive it is called /dev/sda. It is 238G in size.

That correct or incorrect?

The partitions on it show as:
EFI System: 260M
Microsoft reserved: 16M
Microsoft basic data: 185.1G
Windows recovery environment: 980M
Microsoft basic data: 14.5G
Linux filesystem: 29.8G
Linux swap: 7.9G
--------------------------------------
Total: 238G

It would appear that Windows has reserved all of the remaining drive space for itself when you wanted to use only half of the drive space.

GParted can allow you to shrink that partition. However first you should determine if this information make sense about the total capacity of the drive.

/dev/sda is the internal drive.

There's also an external 1Tb USB drive connected that the Hard Disk manager that comes with Mint can see (ie, it identifies it correctly as a Seagate drive, picks up its serial number, and calls it /dev/sdb..) but won't allow me to access to format, create / change partition size etc..

In addition, have you looked at the output of the dmesg command to see if there are any errors reading the drive?

May not mean much but post the output of the command:
file -s /dev/sdb

to michaelk:

chris@chris-HP-Pavilion-Laptop-14-bf1xx ~ $ file -s /dev/sdb
/dev/sdb: no read permission
chris@chris-HP-Pavilion-Laptop-14-bf1xx ~ $

Do you know how to look at your system log?

One good way is to issue the "dmesg" command.

A recommendation is to:

1. Unplug the 1 TB USB drive.
2. Issue the dmesg command to see the log without the drive.
3. Plug in the 1 TB USB drive.
4. Issue the dmesg command again to see the changes to the log now that the drive is plugged in.

It seems Mint sees it somehow, but does not mount it, nor can also understand that partitioning scheme for that drive. Therefore I'm wondering what happens when you plug that drive in and what the system log shows.

Please don't post your entire system log dumps, they'll be too much of non-relevant data. Only the changes added at the end would be relevant.

I did try running dmesg with the drive attached and I noticed this section which refers to /sdb:

[ 5.830425] input: ST LIS3LV02DL Accelerometer as /devices/platform/lis3lv02d/input/input19
[ 5.973145] EXT4-fs (sdb): unable to read superblock
[ 5.973252] EXT4-fs (sdb): unable to read superblock
[ 5.973368] EXT4-fs (sdb): unable to read superblock
[ 5.973486] SQUASHFS error: squashfs_read_data failed to read block 0x0
[ 5.973487] squashfs: SQUASHFS error: unable to read squashfs_super_block
[ 6.125765] audit: type=1400 audit(1518527881.741:2): apparmor="STATUS" operation="profile_load" profile="unconfined" name="/usr/sbin/ippusbxd" pid=866 comm="apparmor_parser"

Does that help at all?

also the following:

579564] [Firmware Bug]: ACPI(PXSX) defines _DOD but not _DOS
[ 3.579570] ACPI: Video Device [PXSX] (multi-head: yes rom: yes post: no)
[ 3.579602] input: Video Bus as /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:35/LNXVIDEO:01/input/input9
[ 3.579651] [drm] Initialized i915 1.6.0 20161121 for 0000:00:02.0 on minor 0
3.594798] sd 3:0:0:0: Attached scsi generic sg1 type 0
[ 3.594991] sd 3:0:0:0: [sdb] Unit Not Ready
[ 3.594993] sd 3:0:0:0: [sdb] Sense Key : Hardware Error [current]
[ 3.594994] sd 3:0:0:0: [sdb] ASC=0x44 <<vendor>>ASCQ=0x81
[ 3.595240] sd 3:0:0:0: [sdb] Read Capacity(16) failed: Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[ 3.595241] sd 3:0:0:0: [sdb] Sense Key : Hardware Error [current]
[ 3.595242] sd 3:0:0:0: [sdb] ASC=0x44 <<vendor>>ASCQ=0x81
[ 3.595493] sd 3:0:0:0: [sdb] Read Capacity(10) failed: Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[ 3.595494] sd 3:0:0:0: [sdb] Sense Key : Hardware Error [current]
[ 3.595495] sd 3:0:0:0: [sdb] ASC=0x44 <<vendor>>ASCQ=0x81
[ 3.595868] sd 3:0:0:0: [sdb] 0 512-byte logical blocks: (0 B/0 B)
[ 3.595869] sd 3:0:0:0: [sdb] 0-byte physical blocks
[ 3.596115] sd 3:0:0:0: [sdb] Test WP failed, assume Write Enabled
[ 3.596202] sd 3:0:0:0: [sdb] Asking for cache data failed
[ 3.596204] sd 3:0:0:0: [sdb] Assuming drive cache: write through
[ 3.596827] sd 3:0:0:0: [sdb] Unit Not Ready
[ 3.596828] sd 3:0:0:0: [sdb] Sense Key : Hardware Error [current]
[ 3.596829] sd 3:0:0:0: [sdb] ASC=0x44 <<vendor>>ASCQ=0x81
[ 3.597077] sd 3:0:0:0: [sdb] Read Capacity(16) failed: Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[ 3.597078] sd 3:0:0:0: [sdb] Sense Key : Hardware Error [current]
[ 3.597079] sd 3:0:0:0: [sdb] ASC=0x44 <<vendor>>ASCQ=0x81
[ 3.597327] sd 3:0:0:0: [sdb] Read Capacity(10) failed: Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[ 3.597327] sd 3:0:0:0: [sdb] Sense Key : Hardware Error [current]
[ 3.597328] sd 3:0:0:0: [sdb] ASC=0x44 <<vendor>>ASCQ=0x81
[ 3.598285] sd 3:0:0:0: [sdb] Attached SCSI disk[/COLOR]
[ 3.654782] fbcon: inteldrmfb (fb0) is primary device
[ 3.654834] Console: switching to colour frame buffer device 240x67
[ 3.654851] i915 0000:00:02.0: fb0: inteldrmfb frame buffer device
[ 3.798753] [drm] RC6 on

Lo and behold, the mere act of re-attaching i seems to have cleared it up, and I can now access the partition and various tools.

Thanks both for your help - much appreciated!