Unable to load ISCSI partition as block device

[SrinathP]

While loading Blocks (Targetcli--> Backstores-->Block), i was not able to load the VG and LV created.
Error Statement - "Block device is already in use"

This error is only observed during RHCE exam setup. I have observed this particular error during months of practice session and there is no solution to rule out this error.

Can someone help with this error please

[Jayadev]

@SrinathP  

I guess both the examiner and the examinee are bound by the NDA and discussing an exam related issue may violate it. If you are an examiner then you should contact the hotline for support. If you are an examinee and think that this is a bug in the exam then you can contact the exam support team by submitting the form at below link

https://www.redhat.com/rhtapps/services/comments/

We should not be discussing exam related issues in this forum.

Thanks,

Jayadev

[NunoMartins]

not to discuss anything possibly exam related - however, im interested in the issue - 

What does running a lvscan show you before configuring the backstore block ?

[SrinathP]

Hi Martin, Apologies for the delayed response. I haven't had a look on email for quite a long time that i missed this request.

When running the lvscan/lvdisplay, it shows the configured lv with provided volume. Even i can see the PV/VG and LV complete path and  no erros observed in that part. But when i tried to load the LV in block, it popped two types of error (given below).

1. This block device is already in use.

2. This device is not a block device 

and i was not able to add it in the block --> backstores

[Tracy_Baker]

I've seen this with my students in the classroom when teaching iSCSI. I just tried it myself, and using an LV as a block-based backing storage worked fine (CentOS 7.6 - since I'm at home).

I'm pretty certain the the problem may be:

1. The LV either had a file system on it and / or was mounted. I left mine unformatted / unmounted.

2. There was a typo when specifying the device file name. I used /dev/<vg_name>/<lv_name>