[SOLVED] Virtual Hard Disk is added, but not showing using lsblk -d command

Shozib · 01-02-2019, 03:27 AM

I have added a virtual disk in Centos, now in the terminal when I type the command lsblk -d it is not showing me the newly added virtual disk whereas all the other hard disks are showing. Could you please tell me, how can I solve this problem? Thanks

berndbausch · 01-02-2019, 04:33 AM

Not sure what you mean. Did you add it to a virtual machine? How did you add it?

I would check for messages in the kernel message buffer. Use dmesg to display it. You can also run udevadm monitor while you (dis)connect the disk to see if udev gets any notification.

Have you tried a reboot after adding the disk?

sgrlscz · 01-02-2019, 06:41 AM

If the VM was running when you added the disk, you need to rescan for the new disk. Rebooting will work, but you can rescan without rebooting.

If the sg3-utils package is installed, you can use rescan-scsi-bus.sh to rescan. If not you can use the following:

Code:

for h in $(ls /sys/class/scsi_host); do
    echo '- - -' > /sys/class/scsi_host/$h/scan
done

Shozib · 01-02-2019, 09:11 AM

@berndbausch yes Sir, I have added this drive to a virtual Machine (Centos 7 64 bit) by going to settings then under hardware tab. And yes rebooting is working, but I want to do this by scanning the drives. I short, basically I want to see the drive in the list, without rebooting the system. Thanks

Shozib · 01-02-2019, 09:14 AM

@sgrlscz Thankyou for your time reading my query and responding back. Could you please tell me, how can I check whether the package (sg3-utils) you mentioned above is installed or not?
And sorry for asking simple questions, actually I am new to this OS. Thanks again.

sgrlscz · 01-02-2019, 01:24 PM

It's actually sg3_utils (sorry about that). To check if it's installed:

Code:

rpm -q sg3_utils

If it's not, you'll get a message saying it's not installed. If it is, you get the full package name. For example:

Code:

$ rpm -q sg3_utils
sg3_utils-1.37-12.el7.x86_64

If it's not installed, you can install it with yum:

Code:

# yum install sg3_utils

Shozib · 01-02-2019, 02:17 PM

@sgrlscz I have run the command to re-scan the disk. The command worked but still I did not get my hard disk listed in the list. Whereas if I reboots the system then the problem gets solved.

Shozib · 01-02-2019, 02:24 PM

Finally the problem is solved with the code you mentioned in your Ist comment, which is #3 in this thread. Thanks a lot.

berndbausch · 01-02-2019, 05:45 PM

Quote:

Originally Posted by sgrlscz

Code:

for h in $(ls /sys/class/scsi_host); do
    echo '- - -' > /sys/class/scsi_host/$h/scan
done

Picking a nit (and because I like to have the last word

). The following doesn’t require the ls command:

Code:

for h in /sys/class/scsi_host/*; do
    echo '- - -' > /sys/class/scsi_host/$h/scan
done