Azure VM (linux centos 8) cannot mount disks

mmac 71

Getting this message when trying to mount restore points. Turned off firewall, selinux - nothing seems to be using the port.

We are unable to communicate via the port 3260 on this machine since it is being used by ISCSI target server or any other application. Please unblock the port or use another machine where the port is open for communicatoin

Mounika Reddy Anumandla 7,135 Reputation points Moderator

2024-11-15T02:49:46.4366667+00:00

Hi mmac,

It sounds like you're facing a persistent issue with port 3260 on your Azure VM running CentOS 8. We are looking into it and will get back to you with details.

Thank you!

Answer accepted by question author

Nikhil Duserla 9,945 Microsoft External Staff Moderator

Hi @mmac,

Thank you for reaching out to us again and confirming that the issue has been resolved.

As an original poster cannot accept their own answer, I am reposting it so that you can accept it an answer. Accepted answer will help other community members navigate to the appropriate solutions.

Issue: We are unable to communicate via the port 3260 on this machine since it is being used by ISCSI target server or any other application. Please unblock the port or use another machine where the port is open for communication.

Solution: Go into system delete all of the targetcli/iscsi entries i had made, save config.

targetcli /iscsi delete targetname targetcli save

targetcli ls

located some of the old python scripts- ran them with the 'clean' option. rebooted. explicitly stopped and started the the service 'systemctl stop target.service' & 'systemctl start target.service'. Confirmed the deletion was still there 'targetcli ls'

Ran a download script and it magically worked.

Random guess - the server was holding on to an older recovery and the steps above cleared something.

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mmac 71 Reputation points

2024-11-18T14:43:18.9633333+00:00

Still no joy.
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mmac 71 Reputation points

2024-11-18T14:45:43.92+00:00

Mounika,

Tried following your instructions but getting stuck, sorry I am not familiar with these commands:

Nikhil Duserla 9,945 Reputation points Microsoft External Staff Moderator

2024-11-20T21:51:34.3566667+00:00

Hi @mmac,

We have noticed that you have rated an answer as not helpful. We appreciate your feedback and are committed to improving your experience with the Q&A. I am reviewing this query and will get back to you as soon as possible.

With Regards,

Nikhil D
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Mounika Reddy Anumandla 7,135 Reputation points Moderator

2024-11-15T05:30:26.6+00:00
Hi mmac,

Welcome to the Microsoft Q&A Platform! Thank you for asking your question here.

The error message you're encountering indicates that there is an issue with the iSCSI connection, specifically related to port 3260, which is the default port used for iSCSI communication.

I would recommend the following troubleshooting steps:
- Since the error message suggests that port 3260 may already be in use, you can check for any processes that might be using this port:
  *sudo netstat -tuln | grep 3260*
- Even though you've turned off the firewall and SELinux, it's worth double-checking that there are no lingering rules that could be affecting the connection.
- Use the following command to check for any active firewall rules: sudo iptables -L -n
- Ensure that SELinux is indeed disabled by running: sestatus
- You can test connectivity to the iSCSI target using telnet or nc (netcat) to see if you can reach the target on port 3260:
  *telnet <IP_ADDRESS_OF_ISCSI_TARGET> 3260*
- If everything seems fine, try using the iscsiadm command to reconnect to the target.
- Sometimes, restarting the iSCSI service can help resolve port conflicts. If you have any further queries, do let us know. If the answer is helpful, please click "Accept Answer" and "Upvote it."
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mmac 71 Reputation points

2024-11-15T15:31:17.8033333+00:00

Server\services rebooted - everything looks correct. Nothing should be accessing the iscsi target. Below can find outputs from various commands. The problem persists.

Telnet from Remote Server

Alex Bykovskyi 2,321 Reputation points

2024-11-15T18:05:03.3133333+00:00

Hey,

As far as I can see, you are using targetcli to create iSCSI target. The connection is refused because you haven't allowed connection from the initiator (add ACL). Default behavior is to reject all. Should help: https://www.server-world.info/en/note?os=Debian_11&p=iscsi&f=1

As another option, you can use StarWind VSAN to create iSCSI target.
https://www.starwindsoftware.com/starwind-virtual-san

Cheers,

Alex Bykovskyi

StarWind Software

Note: Posts are provided “AS IS” without warranty of any kind, either expressed or implied, including but not limited to the implied warranties of merchantability and/or fitness for a particular purpose.

Mounika Reddy Anumandla 7,135 Reputation points Moderator

2024-11-18T01:03:06.4766667+00:00

Hi mmac,

Thank you for reaching back to us again with detailed information. Will be happy to assist you!

I have reproduced the scenario for you and below are the steps to setup an iscsi target server.
Steps to setup iSCSI target

Create the backing storage devices.

Create the IQN and default target portal group (TPG).

Configure one or more ACLs for the TPG.

Create LUNs to provide access to the backing storage devices.

5.Create a portal to provide a network interface that iSCSI initiators can connect to.

6.Verify and commit the configuration.
Discover the target using the below command.

After the discovery below database is updated

As Alex Bykovskyi, suggested it looks like you haven't configured the ACL, and it is rejecting the connection by default.

Please try the above suggested troubleshooting step and if you still face the issue, I can share you the detailed document.

If you have any further queries, do let us know.

If the answer is helpful, please click "Accept Answer" and "Upvote it."
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Azure VM (linux centos 8) cannot mount disks

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