Tag Archives: Operation and maintenance

[Error resolution] paramiko.ssh_exception.SSHException: Error reading SSH protocol banner setting

Error message
In the morning, my colleague in the data group told me that there were several programs reporting errors. After checking the log, the error message was found:

paramiko.ssh_exception.SSHException: Error reading SSH protocol banner

After a search, it was revealed that the error was caused by the banner_TIMEOUT default setting being too short, only 15s.
Error analysis
See the transport code under Paramiko library. Py:

class Transport(threading.Thread, ClosingContextManager):
        self.banner_timeout = 15
        # how long (seconds) to wait for the handshake to finish after SSH

Reset the banner_TIMEOUT property value
Most of the methods on the Internet is to modify the source code, reinstall, feel a little trouble. I’m going to reset the properties in the code.

transport = paramiko.Transport((self.host, self.port))
transport.banner_timeout = 30

After testing, the two printed property values are different, indicating that the property is set successfully and the problem is solved.

Reproduced in: https://www.cnblogs.com/everfight/p/paramiko_ssh_exception.html

KVM–Host does not support any virtualization…

Phenomenon: When virt-install creates a new virtual machine, prompt Host does not support any Virtualization options.
environment: CentOS7, KVM, CPU: Intel(R) Xeon(R) CPU e5-2609,
qemu-kvm, qemu-kvm-tools, virt-manager, libvirt virt-install four major components have been normally installed,
selinux has been closed, iptables have been fully released,
processing steps:
1. General step, advanced BIOS to see whether the CPU is on virtualization, confirm that
2, grep-e ‘(VMX | SVM)’ /proc/cpuinfo, check whether there is echo information, found that there is, also means that step 1 is not blind. Grep KVM
3, dmesg |, grep KVM, the actual function is the same as step 1 and step 2, confirm again whether the host supports virtualization, if not, KVM :disabled by BIOS will be displayed, here I do not have any echo. 4. At this point, the usual solutions on baidu and Google have come to an end and the problem has not been solved… Only themselves to think of a way, here a little fooling around step ten thousand steps.
5, systemctl status libvirtd suddenly found that there was an error in the libvirt log:
internal error: Failed to probe QEMU binary with QMP: /usr/libexec/ qem-kvm: relocation error: /lib64/ libspy-server. so.1
6, baidu learned that spice server is provided as a library for qemu use, compiled is libspice server.
, however, is a completely unknown thing to debug and debug, so let’s see if qemu- KVM has any problems.
7, ll /usr/libexec/qemu- KVM first see if qemu- KVM has execution permissions, found that there is, then normal.
8, /usr/libexec/qemu-kvm –version run manually, find error:
version libssl.so.10 not defined in file libssl.so.10
9, still get the solution through baidu solution:
/usr/libexec/qemu-kvm –version normal display version
failure solved successfully!
/usr/libexec/qemu-kvm –version
failure solved! Thank:

https://blog.51cto.com/506554897/1972914 http://bbs.chinaunix.net/thread-3691547-1-1.html

Reproduced in: https://blog.51cto.com/7308842/2395997

standard_init_linux.go:178: exec user process caused “no such file or directory”

Golang Docker Build runs an error after making the input
The problem arises because the environment in which you are compiling is different from the environment in which you are running, and may have dependencies on dynamic libraries
1. By default, go USES static linking and dynamic compilation is used in Docker’s Golang environment.
2. If you want to compile +alpine to deploy with docker, you can do so by disabling cgoCGO_ENABLED=0.
3. If you want to use cgo, make GCC statically compiled by go build --ldflags "-extldflags -static".
Reference: https://yryz.net/post/golang-docker-alpine-start-panic.html

Reproduced in: https://www.cnblogs.com/davygeek/p/10969434.html

Info:Memory module [DIMM] needs attention: Single-bit warning error rate exceeded, Single-bit fai…

Why can’t 80% of code farmers be architects?> > >
Dell server hardware monitoring software OpenManager, can monitor the battery, motherboard, temperature, hard disk, and so on. See installation usage
While monitoring OpenManage(OMSA) for Dell Server installation, you may encounter the following error message: Info:Memory Module 6 [DIMM7, 2048 MB] Needs attention: single-bit warning error rate Exceeded, Single-bit Failure Error rate Exceeded. Need to shut down and replug the memory bar. Due to the need to shut down service shutdown, will affect the business. But the problem will always be reported. Everyone would be upset if they got an alarm. Memory monitoring can be shielded as follows:

check_openmanage --check storage -b dimm=all

can see that the memory and Voltage are not tested. Memory will be detected without dimm=all.
is able to block the detection of relevant hardware. Such as temperature detection and so on. Such as:

/usr/local/nagios/libexec/check_openmanage --check storage -b ctrl_fw=all/ctrl_driver=all/ctrl_stdr=all/bat_charge=all/encl=all/ps=all/fan=all/temp=all/volt=all

Please quote from
Dimensional time: http://www.ttlsa.com/html/3880.html

Reproduced in: https://my.oschina.net/766/blog/211381

No Internet access error 137 (net::ERR_NAME_RESOLUTION_FAILED): Solution to unknown error

Internet Explorer, Chrome can’t surf the Internet, but Firefox can, QQ and other clients can also surf the Internet.

chrome error code: error 137 (net::ERR_NAME_RESOLUTION_FAILED): unknown error.

thought it was a DNS resolution problem, so it changed to and so on. I can’t.

the reason is that I installed a local PHP running server: APMServ5.2.6. After using its software conflict resolution feature, I found a problem:

Finally, administrator open CMD →netsh winsock reset → restart the computer and solve the problem.

source: http://hi.baidu.com/tzg18/item/dbf826f2fd683f733d198b1b

DHCP principle and experimental verification

I. Function overview
The main function of DHCP (Dynamic Host Configuration Protocol) is to centrally manage and assign IP addresses, so that hosts in the network environment can dynamically obtain IP address, Gateway address, DNS server address and other information, and improve the utilization rate of addresses.
DHCP protocol adopts the client/server model: When the DHCP server receives the address application information from the network host, it will send the relevant address configuration information to the network host to realize the dynamic configuration of the network host address information.
Ii. Working principle
DHCP USES UDP as the transport protocol. The host sends the request message to port 67 of DHCP server, and the DHCP server responds the reply message to port 68 of the host. The detailed interaction is as follows.
(1) DHCP Client sends DHCP Discover message by broadcasting.

    (2) all DHCP servers can receive DHCP Discover message sent by the DHCP Client, and all DHCP servers will give a response and send a DHCP Offer message to the DHCP Client. (3) The “Your(Client) IP Address” field in the DHCP Offer packet is the IP Address that DHCP Server can provide to THE DHCP Client, and DHCP Server will put its IP Address in the “Option” field so that DHCP Client can distinguish different DHCP servers. The DHCP Server will have a record of the assigned IP address after sending this message. (4) DHCP Client can only handle one DHCP Offer packet among them, and the general principle is that DHCP Client can handle the DHCP Offer packet that it receives first. (5) The DHCP Client will send a broadcast DHCP Request message, and add the IP address and the required IP address of the selected DHCP Server into the option field. (6) After the DHCP Server receives the DHCP Request message, it shall determine whether the IP address in the option field is the same as its own address. If it is not the same, DHCP Server does not do anything but clear the corresponding IP address assignment record; If the same is true, the DHCP Server will respond to the DHCP Client with a DHCP ACK packet and add the usage lease information for the IP address in the options field. (7) After the DHCP Client receives the DHCP ACK packet, it shall check whether the IP address assigned by the DHCP Server can be used. If it can be used, then the DHCP Client successfully obtains the IP address and automatically starts the renewal process by using the lease term according to the IP address; If the DHCP Client finds that the assigned IP address has been used, the DHCP Client will send the DHCP Decline message to the DHCPServer, notify the DHCPServer to disable this IP address, and then the DHCP Client will start the new address application process. (8) After the DHCP Client successfully obtains the IP address, it can Release its IP address at any time by sending THE DHCP Release message. After the DHCP Server receives the DHCP Release message, it will recover the corresponding IP address and reassigned it. 3. Experimental verification: After DHCP services are configured on servers and network devices (routers and switches), DHCP can generally be used as DHCP servers. In this experiment, routers were used to simulate the network topology, as shown in the figure below: In the diagram, routers were dhCP-server and switches were two-layer devices (switch ports connected to PC1-6 hosts were all in the default VLAN 1).

1. Before the configuration of dhcp-server is completed, PC1 is configured to DHCP to get the IP address, which is shown as follows:

The result shows “DHCP failed. APIPA is being used”, indicating that the IP address was not successfully obtained (generally a “” segment address is displayed, indicating that the IP address was not obtained from the DHCP server).
2. Configure DHCP related information on the router:
(1) configure port IP as shown in the figure below:

(2) configure DHCP service as shown in the figure below:

3. At this point, verify the IP address acquisition above PC1:

As can be seen from the figure above, PC1 successfully obtained the CONFIGURATION information of IP address, gateway, DNS-Server, etc.

Reproduced in: https://blog.51cto.com/13401027/1977218

SSH connection to MAC server shows No route to host solution

First, the MAC operating system is 10

When other computers SSH into a MAC server, sometimes they can log in, and the display shows no route to host
Jenkins installed on the MAC was also accessed through the browser, but the response was slow. After the following modifications, it could be used normally.
1. System preference setting & GT; > Sharing & gt; > Check file sharing, log in, remote management

It is also possible that the computer is in sleep state, so cut off the network, the following configuration, so that the computer does not go to sleep even if the monitor is turned off.
2. System preference setting & GT; > Energy-saving & gt; > When the monitor is turned off, prevent the computer from falling asleep automatically

3. Desktop and Protector & GT; > Screen saver & GT; > Idle options before starting [never]

With reference to

Reproduced in: https://www.cnblogs.com/kaerxifa/p/11382652.html

ESXi creates datastore error Fail to create VMFS datastore solution

When you create a new data warehouse datastore in VMware vShere/ESXi, the following error message pops up! “Fail to create VMFS Datastore VMFS XXXX” – Cannot change the host Configuration. For the first time, it’s hard to know what to do about this bug, so here’s how to fix it!

Log in to your VMware vShere/ESXi host using SSH or Telnet, and run the following command, which lists all the storage partitions, and then copy out the ID number of the partition where the creation failed. My example is shown in red below.

Then enter the copied id after the following command:

Then fix it with the following command:

With the above fixes, you can go back to VMware vShere/ESXi host again to create datastore and no longer report errors!
Attach a KB for reference: https://kb.vmware.com/s/article/1008886

Pod reports error “Back-off restarting failed container” solution

Pod error “back-off Restarting Failed Container” solution

  Type     Reason          Age                  From                         Message
  ----     ------          ----                 ----                         -------
  Normal   Scheduled       3m                   default-scheduler            Successfully assigned default/jenkins-master-deploy-6694c4f497-r46fn to master.localdomain
  Normal   SandboxChanged  85s                  kubelet, master.localdomain  Pod sandbox changed, it will be killed and re-created.
  Normal   Pulled          83s (x5 over 2m59s)  kubelet, master.localdomain  Container image "drud/jenkins-master:v0.29.0" already present on machine
  Normal   Created         83s (x5 over 2m59s)  kubelet, master.localdomain  Created container jenkins-master
  Normal   Started         81s (x5 over 2m59s)  kubelet, master.localdomain  Started container jenkins-master
  Warning  BackOff         78s (x9 over 2m57s)  kubelet, master.localdomain  Back-off restarting failed container

reference page:

https://serverfault.com/questions/924243/back-off-restarting-failed-container-error-syncing-pod-in-minikube in deployment that mirror followed by the command
command: [“/bin/bash “, “- ce”, “tail -f/dev/null”]

kind: Deployment
apiVersion: apps/v1beta2
    app: jenkins-master
  name: jenkins-master-deploy
  replicas: 1
      app: jenkins-master
        app: jenkins-master
      - name: jenkins-master
        image: drud/jenkins-master:v0.29.0
        imagePullPolicy: IfNotPresent
        command: [ "/bin/bash", "-ce", "tail -f /dev/null" ]
        - mountPath: /var/jenkins_home/
          name: masterjkshome
        - containerPort: 8080
      - name: masterjkshome
          claimName: pvcjkshome


Login failed in rabbitmq

First, use the following command to see why the log is logged:

 tail /var/log/rabbitmq/rabbit\@wzb1.log

Note: The default user guest only allows localhost login.
To create a remote login user, the guest user can only run under localhost:

rabbitmqctl add_user admin admin
rabbitmqctl set_user_tags admin administrator
rabbitmqctl set_permissions -p/admin ".*" ".*" ".*"


Mac install pycurl error: python setup.py egg_info" failed with error code 1”

(env3) [MrYang:Desktop]$ python3 -m pip install pycurl
Looking in indexes: http://mirrors.aliyun.com/pypi/simple/
Collecting pycurl
  Downloading http://mirrors.aliyun.com/pypi/packages/e8/e4/0dbb8735407189f00b33d84122b9be52c790c7c3b25286826f4e1bdb7bde/pycurl- (214kB)
    100% |████████████████████████████████| 215kB 3.1MB/s
    Complete output from command python setup.py egg_info:
    Using curl-config (libcurl 7.43.0)
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/private/var/folders/dx/m2t9qg010gg9pk5v8xzt4gxc0000gn/T/pip-install-bn546qog/pycurl/setup.py", line 913, in <module>
        ext = get_extension(sys.argv, split_extension_source=split_extension_source)
      File "/private/var/folders/dx/m2t9qg010gg9pk5v8xzt4gxc0000gn/T/pip-install-bn546qog/pycurl/setup.py", line 582, in get_extension
        ext_config = ExtensionConfiguration(argv)
      File "/private/var/folders/dx/m2t9qg010gg9pk5v8xzt4gxc0000gn/T/pip-install-bn546qog/pycurl/setup.py", line 99, in __init__
      File "/private/var/folders/dx/m2t9qg010gg9pk5v8xzt4gxc0000gn/T/pip-install-bn546qog/pycurl/setup.py", line 316, in configure_unix
        specify the SSL backend manually.''')
    __main__.ConfigurationError: Curl is configured to use SSL, but we have not been able to determine which SSL backend it is using. Please see PycURL documentation for how to specify the SSL backend manually.

Command "python setup.py egg_info" failed with error code 1 in /private/var/folders/dx/m2t9qg010gg9pk5v8xzt4gxc0000gn/T/pip-install-bn546qog/pycurl/

The solution is as follows
# First upgrade PIP
Sudo Python-m PIP install — Upgrade — Force PIP
You can then specify the version number to install (the version number can be found in the error log)
Sudo PIP install pycurl = = 7.43.0

FileZilla Server prompts 550 Could not open file for reading when downloading files (illustration)

This error prompts me to study for an hour, finally found that it was because the downloaded file was occupied by another program, so it could not be downloaded.
Open the FileZilla Server admin screen – Settings -Miscellaneous-Allow M.E. of files which are open for writing by another process.
The diagram below: