Brocade SAN switch CLI Commands for troubleshooting minor issues

We have already discussed about, Brocade SAN switch Zoning steps Via CLI and CISCO MDS Zoning steps via CLI

This write-up, focuses on the basic trouble shooting commands used in Brocade SAN switch. For better understanding of the commands, let us first understand the day to day operational challenges faced in the SAN fabric. Listed below are few of the operational error codes/prompts:

  1. Alias/port went offline
  2. Bottlenecks
  3. Port error
  4. Hanging zones
  5. Rx Tx Voltage/Power Issue

let’s read in brief about, how to identify the errors and how to troubleshoot them. Read more

Alias/port went offline

This error is recorded due to the following reasons:

  1. Reboot/ Shutdown of the host
  2. Faulty cable
  3. Issue in the HBA card.

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Thus, when ‘WWN/ Alias went offline’ is recorded, use the below mentioned commands to identify, when the port went offline and which port went offline.

#fabriclog -s                                                                              States the ports which went offline recently.

#fabriclog -s |grep -E “Port Index |GMT”                               This command states the ports which went offline before. Note: This command will fail in case the FOS upgrade or Switch reboot activity was performed. As both the activities clear the fabriclog.

In order to know the zoning details through the WWN of the device, use below mentioned command:  

#alishow |grep wwn -b2                                                              This lists the alias.

then use below command

#zoneshow –alias Alias_Name                                                    This lists the zone name and component aliases.

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There are many kinds of bottlenecks. But, the once prominent in SAN fabric are Latency bottleneck and congestion bottleneck.

Latency bottleneck occurs when a slow drain device is connected to the port. Even initiator or target ports can report latency, no matter what kind of port it is, if a slow drain device is attached, there will be bottleneck in that port. A

Slow drain devices, is a device which either has all or any one of the bellow mentioned issues:

  1. Unsupported firmware.
  2. Hardware issues.
  3. SFP which has a voltage or power issue.

Whereas, Congestion bottleneck occurs due to high rate of data transfer in the port. In the next write-up we will discuss in detail, about the causes of a congestion bottleneck.

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The commands used to identify latency as well as congestion bottleneck are:


#mapsdb –show

If there is latency or congestion bottleneck, it should to be fixed by logging a support case with Server/Storage hardware vendor.

Port errors

There are many kinds of port errors. Most of the time, its due to bottleneck issue/ physical layer issue. Bottleneck issue we have already addressed above. Physical layer issue is, either Cable issue or SFP issue.

Below are the commands to identify the port errors:

#porterrshow                                                       This will list all ports in error state.

#porterrshow port_number                       

#porterrorshow -i Port_Index                              Both these commands will list the errors in a particular port.

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In case an error is listed, before troubleshooting clear the status using below commands and observe it again.



#portstatsclear port_number

Apart from this, there are other commands to display the current data transfer rate of a port or all ports, such as:


#portperfshow port_number

Hanging Zone

Hanging zones are the purposeless zones residing in the zoning configuration. The zone in which all initiators or all targets are inactive are considered as hanging zone.

There is no specific command to list out hanging zones in the fabric, we have to use SAN health to identify the hanging zone. To check if all the aliases of a zone are active or not use the command mentioned below:

#zonevalidate “zonename

In the result of the above command, there will be have a ‘*’ mark at the end of each active alias in the zone.

Rx Tx Voltage/Power Issue

The Rx & Tx Voltage and power of an SFP can be validated only if, there is connectivity in the SFP with its port in online state.

The command below will display the voltage, power and all the details related to the SFP.

#sfpshow port_number -f


Please feel free to connect with us in case of any queries. Also, please give us your feedback, it will help us to improve our skill sets.

Troubleshooting NFS Mount Issues in Linux

Network File System (NFS) is a protocol which allows a system to share directories and files with others over a network. By using NFS, users and programs can access files on remote systems almost as if they were local files.

This post refers how to mount the network share in our local system and what are all the common issues and how to generally troubleshoot connectivity and config issues.

NFS Client Configuration

1. Install the required nfs packages if not already installed on the server Read more

# rpm -qa | grep nfs-utils

# yum install nfs-util

2. Use the mount command to mount exported file systems. Syntax for the command:

# mount -t nfs -o options host:/remote/export /local/directory 

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Example :

# mount -t nfs -o ro,nosuid remote_host:/home /remote_home

This example does the following:
– It mounts /home from remote host (remote_host) on local mount point /remote_home.
– File system is mounted read-only and users are prevented from running a setuid program (-o ro,nosuid options).

3. Update /etc/fstab to mount NFS shares at boot time.

# vi /etc/fstab

remote_host:/home      /remote_home nfs        ro,nosuid           0            0

Troubleshooting NFS connectivity issues

Depending on the client and the issue, wide range of error messages can appear while trying to mount an NFS share, it might also take forever to mount, or even mount normally but the mount points will be empty.Below are the common errors we face in the client side while mounting the NFS/NAS shares.

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Error 1: 

mount: mount to NFS server 'NFS-Server' failed: System Error: No route to host.

This can be caused by the RPC messages being filtered by either the host firewall, the client firewall, or a network switch. Verify if a firewall is active and if NFS traffic is allowed. Normally nfs is using port 2049.

  1. Check the show mount output of the server to verify the filesystem has exported for the client ip.
# showmount –e <NFS server IP > | grep –I  <clientIP>

Check the port Connectivity of the NFS server using telnet

# telnet <NFS server IP> 2049


Error 2:

mount_nfs: can't mount / from onto /mnt: RPC prog. not avail

Error: “mount clntudp_create: RPC: Port mapper failure – RPC: Unable to receive

The Linux NFS implementation requires that both the NFS service and the portmapper (RPC) service be running on both the client and the server. Check it like this:

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            # rpcinfo -p
     program vers proto   port  service

    100000    4   tcp    111  portmapper

    100000    3   tcp    111  portmapper

    100000    2   tcp    111  portmapper

    100000    4   udp    111  portmapper

    100000    3   udp    111  portmapper

    100000    2   udp    111  portmapper...

          # ]# systemctl status rpcbind
  •  rpcbind.service - RPC bind service
             Loaded: loaded (/usr/lib/systemd/system/rpcbind.service; indirect; vendor preset: enabled)

            Active: active (running) since Fri 2018-05-18 12:39:15 IST; 2s ago

            Process: 15222 ExecStart=/sbin/rpcbind -w $RPCBIND_ARGS (code=exited,      status=0/SUCCESS)

 Main PID: 15223 (rpcbind)

            CGroup: /system.slice/rpcbind.service

           └─15223 /sbin/rpcbind -w


May 18 12:39:15 nfsserver systemd[1]: Starting RPC bind service...

May 18 12:39:15 nfsserver systemd[1]: Started RPC bind service.

If not, start it with the commands give below.

# systemctl start rpcbind

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Error 3: 

Error: “NFS Stale File Handle”

Unlike traditional Linux file systems that allow an application to access an open file even if the file has been deleted using unlink or rm, NFS does not support this feature. An NFS file is deleted immediately. Any program which attempts to do further I/O on the deleted file will receive the “NFS Stale File Handle” error. For example, if your current working directory is an NFS directory and is deleted, you will see this error at the next shell prompt.

To refresh the client’s state with that of the server you may do a lazy unmount the mount point and remount it

# umount -l /mnt/mount_point

or kill the process, which references the mounted file system:

# fuser -k [mounted-filesystem].

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Error 4:

Error: “Access Denied” or “Permission Denied

Check the export permissions for the NFS file system. You can do this from the client:

# showmount -e server_name


Error 5:

Error: “rpc mount export: RPC: Timed out

Unable to access file system at [NFS SERVER]: rpc mount export: RPC: Timed out This is caused by DNS name resolution issue. NFS(RPC) needs reverse name resolution. If NFS server or client cannot resolve their name, this error occurs. In case gets the error message, check DNS configuration and /etc/hosts configuration.


Hope we have covered almost all the regular errors and steps for solving those. Please share your thoughts in the comments section. If you want us to add any additional issues-resolution, kindly let us know.

Thanks for reading..!