Even though the Catalyst 2960 series got introduced back in 2005, is in End-of-Sale since October 2014 and End-of-Support since October 2019. They are still used in smaller businesses or lab environments. Therefore a complete reset is sometimes required. For example if you want to reuse your old switch, create a new lab environment or if you run into uncommon problems.

This guide is also valid for the 2960X models, their End-of-Support Date is October 2026. However their End-of-Sale Date is October 2021, but you may still be able to buy used units.
The following provides a simple step-by-step guide to follow along.

Overview

Here you can find an overview of all models supported. Keep in mind that the same commands may still work on older or newer models.

Requirements

There aren’t many requirements, but I still want to mention them beforehand.
The only requirement is a console cable and be able to push the Mode button on the switch. That’s it.

Resetting the Switch

Step 1 – Mode Button Location

Before you continue refer to the following pictures on where to find the Mode button on your switch model:

Catalyst 2960

Number 9 shows the location of the Mode button on all 2960 models:

Catalyst 2960X

Number 5 shows the location of the Mode button on all 2960X models:

Step 2 – Press Mode Button

Connect to the switch via console cable and make sure the connection is established.
Power off the switch and hold down the Mode button. While holding down the Mode button power on the switch. Keep holding down the Mode button!

Hold down the Mode button until you see the following output:

Using driver version 1 for media type 1
Base ethernet MAC Address: 00:00:00:00:00:00
Xmodem file system is available.
The password-recovery mechanism is enabled.
The system has been interrupted prior to initializing the
flash filesystem. The following commands will initialize
the flash filesystem, and finish loading the operating
system software:
flash_init
 boot
switch:

Step 3 – Initialize Flash

To continue you need to initialize the flash file system.
This can be done with the following command:

flash_init

Your output should then look similar to the following:

switch: flash_init
Initializing Flash...
mifs[2]: 10 files, 1 directories
mifs[2]: Total bytes : 1806336
mifs[2]: Bytes used : 612352
mifs[2]: Bytes available : 1193984
mifs[2]: mifs fsck took 1 seconds.
mifs[3]: 0 files, 1 directories
mifs[3]: Total bytes : 3870720
mifs[3]: Bytes used : 1024
mifs[3]: Bytes available : 3869696
mifs[3]: mifs fsck took 0 seconds.
mifs[4]: 5 files, 1 directories
mifs[4]: Total bytes : 258048
mifs[4]: Bytes used : 9216
mifs[4]: Bytes available : 248832
mifs[4]: mifs fsck took 0 seconds.
mifs[5]: 5 files, 1 directories
mifs[5]: Total bytes : 258048
mifs[5]: Bytes used : 9216
mifs[5]: Bytes available : 248832
mifs[5]: mifs fsck took 1 seconds.
 -- MORE --
mifs[6]: 566 files, 19 directories
mifs[6]: Total bytes : 57931776
mifs[6]: Bytes used : 28429312
mifs[6]: Bytes available : 29502464
mifs[6]: mifs fsck took 21 seconds.
...done Initializing Flash.

After the flash initialization is complete you can continue with the next step.

Step 4 – Delete Config Files

To clear the switch configuration we need to delete two files. These are the config.text and vlan.dat file.
If you want to keep the VLAN configuration for example you can simply skip the second step and only delete the config.text file.

Delete config.text

Use the following command to delete the config.text file from the flash directory:

del flash:config.text

Confirm the command with y. Your output should look similar to this:

switch: del flash:config.text
Are you sure you want to delete "flash:config.text" (y/n)?y
File "flash:config.text" deleted

Delete vlan.dat

Use the following command to delete the vlan.dat file from the flash directory:

del flash:vlan.dat

Confirm the command with y. Your output should look similar to this:

switch: del flash:vlan.dat
Are you sure you want to delete "vlan.dat" (y/n)?y
File "flash:vlan.dat" deleted

Step 5 – Reboot

Great, the configuration is now deleted. You need to reboot with the following command:

boot

After the reboot is done you should be greeted with the initial configuration dialogue:

switch: boot
Loading "flash:c2960s-universalk9-mz.122-58.SE2.bin"...
--- System Configuration Dialog ---
Enable secret warning
----------------------------------
In order to access the device manager, an enable secret is required
If you enter the initial configuration dialog, you will be prompted for the enable secret
If you choose not to enter the intial configuration dialog, or if you exit setup without setting the enable secret,
please set an enable secret using the following CLI in configuration mode-
enable secret 0 <cleartext password>
----------------------------------
Would you like to enter the initial configuration dialog? [yes/no]:
% Please answer 'yes' or 'no'.

The resetting process is now complete. You can either continue with the configuration dialog or skip it and start building your new config.

Conclusion

Resetting your switch configuration is not difficult and can be useful in many scenarios. As mentioned before this guide may still be valid for other Cisco Catalyst models.

“dnf repoquery –installonly” komutu ile aktif kernel listesini görebilirsiniz.

Kaldırmak istediğiniz, kerneli listeden bulup alttaki örnek komut ile kaldırabilirsiniz.

“dnf remove kernel-core-0:5.14.0-503.34.1.el9_5.x86_64”

dnf remove $(dnf repoquery –installonly –latest-limit=-2 -q) bu komut ilede son 2 kernel hariç diğer kernelleri temizleyebilirsiniz.

Ayrıca /etc/yum.conf dosyası içinde bulunan installonly_limit=3 sayısını değiştirirek kaç tane kernelin aktif olarak kalmasını istediğinizi ayarlayabilirsiniz.

Vmware in kullandığı Vmdk için kısaca sanal bir makineye ait hard disk formatı diyebiliriz.Vmdk dosyası normal şartlarda 2 adet dosyadan oluşur.(Datastore browser dan baktığımızda sadece bir adet vmdk görebiliriz)

Bunlar “vmismi.vmdk ve vmismi-flat.vmdk” dir

Normal şartlarda datastore tarafından browse ettiğimizde sadece vmismi.vmdk dosyasını görebiliyoruz.

Putty ile bağlanarak kontrol ettiğimizde ise 2 dosyayı da ayrı ayrı görebiliriz.

TESTVM-flat.vmdk boyutundan da anlaşılacağı gibi dataların yer aldığı bölümdür.TESTVM.vmdk ise bu flat disk e ait bilgileri veren ve onu tanımlayan vmdk dosyasıdır.Diske ait  cid,parent cid,flat dosyasının yeri ve diskle ilgili diğer bilgileri barındırır.

Vmdk dosyası bir şekilde silindiğinde veya zarar gördüğünde elinizdeki vmismi-flat.vmdk dosyasını direkt olarak esx ekleme şansız bulunmamaktadır.Bu diski flat dosyasını tanımlayacak bir vmdk dosyasına ihtiyaç bulunmaktadır.

Vmdk dosyası bolzulduktan sonra datastore üzerinden browse ettiğinide vmdk dosyasının simgesinin alışmış olduğunuz vmdk simgesi gibi olmadığını görebilirsiniz

Görüldüğü gibi TESTVM.vmdk dosyası yok ve artık flat dosyasını görebiliyoruz. Flat dosyası bir descripter vmdk dosyasına sahip olmadığı için görülebilmektedir.

Sanal makineyi power on yapmaya çalıştığımızda ise aşağıdaki hata ile karşılaşacağız.

“Cannot open the disk ‘TESTVM.vmdk’ or one of the snapshot disks it depends on.

The system cannot find the file specified

VMware ESX cannot find the virtual disk “TESTVM.vmdk”. Verify the path is valid and try again.”

Bu aşamada yapılması gereken  işlem;

Yenibir sanal disk oluşturmak (sanal disk oluştuğunda 2 adet dosya oluşacak yenidisk.vmdk ve yenidisk-flat.vmdk)

Yeni disk i oluşturduktan sonra yeni disk in vmdk dosyasını (flat olanı değil) yenidisk.vmk dosyasını TESTVM-flat.vmdk dosyamızı tanımlayacak şekilde tekrar düzenlemek.

Putty ile server a bağandıktan sonra ilgili vm in olduğu directory e gidin

Ls –l komutu ile gerçekten vmdk dosyasının olmadığını ve  flat dosyasının yani datayı barındıran diskin olduğunu doğrulayın

Bu işlem için kullanılacak yeni diski oluştururken dikkat edilmesi gereken nokta ilgili vm in config dosyası yani vmx dosyasının içerisine bakılarak. Description dosyası bozuk olan diskin tam boyutu ve sanal makinede kullanılan SCSI Controler adapter ın aynı olmasıdır

Öncelikle flat dosyasının size ını kontrol edelim

Komut: ls -l

Görüldüğü gibi flat disk in size ı 10737418240

Şimdi sanal makinenin kullandığı controller type ına bakalım

Komut: vi sanalmakineismi.vmx  veya less *.vmx | grep virtualDev yazarak gelen satırlardaki  yazıyı görebilirsiniz

scsi0.virtualDev = “lsilogic”

ihtiyacımız olan bilgileri aldıktan sonra aynı özelliklerde sanal disk oluşturacağız. Oluşturacağımız disk in boyutu flat disk ile aynı olacak fakat thin disk oluşturduğumuz içn boyutu çok daha küçük olacak.

Yeni diski aşağıdaki komut ile oluşturabiliriz

Komut :vmkfstools -c 10737418240 -a lsilogic -d thin yenidisk.vmdk

-c create etmek için

Sonraki rakam sizin disk size ınız

-a adepter type

Lsilogic olan kısım sizin adepter type ınız

-d disk in yapısını belirtmek için (thin disk oluşturacağız)

Yenidisk.vmdk  vermek istediğiniz isim

Yeni disk oluştuktan sonra yeni disk in vmdk dosyasını kaypveya bozuk olan vmdk dosyamın adı ile değiştiriyorum

Benim kayıp olan diskmi TESTVM.vmdk bu nedenle yeni disk in vmdk dosyasını bu isimle değiştiriyorum

Artık elimizde TESTVM.vmdk adında bir dosyamız var fakat bu dosyanın içerisinde tanımı olan diski bizim TESVM-flat.vmdk  i işaret edecek şekilde değiştirmeliyiz.Bunun için Vi komutu ile TESTVM.vmdk dosyasının içerisine giriyoruz ve

# Extent description

RW 20971520 VMFS “TESTVM-flat.vmdk”

Kısmındaki vmdk in ihtiyacımız olan flat disk i gösterecek şekilde değiştiriyoruz

Son olarak;

Eğer problem yaşayan disk thin provision olarak yapılandırılmadı ise aşağıdaki satırı silebilriz

Değişiklikleri yapıp kaydettikten sonra vm i poweron yapabilriz.
Aşağıda diskin düzeldikten sonraki halini görebiliriz

Biraz sakat bir konu olduğu için elimden geldiğince detaylı yazmak istedim. Gerçi bu blog a benden başka giren varmı emin değilim J

Eğer snapshot almışşsanız yapılması gerken işlemler biraz daha değişik olacaktır bunu da ayrı bir yazıda belirteceğim

You may come across an issue when trying to access the iDRAC virtual console.
When attempting to launch iDRAC virtual console you may get the following error.

If you click Details
it may something about a certificate issue.
Click Close, exit out of the iDRAC Java applet

The java.security file will need to be edited to allow SSL certificates lower than 1024 bits encryption.

Navigate to C:\Program Files (x86)\Java\<version>\lib\security\
Right click on the java.security file and Open With Notepad

Search for the string (CTRL +F) named
jdk.jar.disabledAlgorithms=MD2, MD5, RSA keySize < 1024

Once found, put a hashtag (#) infront of it to disable this setting

Save the java.security file to the Desktop as it will not let you directly save it to the current file path.
Once saved drag and drop the java.security file from the Desktop into the Java path you were previously in.
C:\Program Files (x86)\Java\<version>\lib\security\

Overwrite the current java.security file

Go back into the iDRAC and download a new Virtual Console Java applet.
You should no longer have the error message that was being displayed.

YOU MAY NEED TO PORT FORWARD PORT 5900 TCP if having ‘Connection has been dropped’ issue

The first thing is error to launch Virtual Console Unable to Launch The Application

like picture below : (click to zoom)

Then I solved with editing some security configuration on java
going to C:\Program Files (x86)\Java\jre1.8.0_251\lib\security Then edit the file java.security
give commend on the line like below picture

Second problem I facing Connection Failed on my IDRAC  like picture below

Still on the same file, go to different line below and comment its

Don’t forget to add security exception on the java configuration then try to access it’s console again!

Solved

Windows Defender Credential Guard does not allow using saved credentials

Yukarıda yazan ”Windows Defender Credential Guard Kaydedilmiş Kimlik Bilgilerini Kullanmaya İzin Vermiyor” hatasını aldığınızda istemci bilgisayarınızda yapmanız gerekenler sırası ile;

çalıştır’a regedit.exe yazıp açılan pencerede,

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\DeviceGuard alanına gidin ve 2 adet dword değer oluşturun

1) EnableVirtualizationBasedSecurity isminde değeri 0 olacak

2) RequirePlatformSecurityFeatures isminde değeri 0 olacak

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa alanına gidin ve 1 adet dword değer oluşturun

1) LsaCfgFlags isminde değeri 0 olacak.

Sonrasında istemci bilgisayarınızı yeniden başlatın artık şifrelerinizi kaydedebileceksiniz.

As with any vSphere release, you should always carefully review the release notes when they are made available and verify that all of your hardware and the underlying components are officially listed on the VMware HCL, which will be updated when vSphere 8 and vSAN 8 GA’s. This is the only way to ensure that you will have the best possible experience and a supported configuration from VMware.

Disclaimer: The following considerations are based on early observations using pre-GA builds of vSphere 8 and it does not reflect any official guidance or support from VMware.

CPU Support

The following CPU generations listed below for both Intel and AMD will not be supported with vSphere 8.

• Intel
  • SandyBridge-DT, SandyBridge-EP/EN
  • IvyBridge-DT, IvyBridge-EP/EN, IvyBridge-EX
  • Haswell-DT, Haswell-EP, Haswell-EX
  • Broadwell-DT/H
  • Avoton
• AMD
  • Bulldozer – Interlagos, Valencia, Zurich
  • PileDriver – Abu Dhabi, Seoul, Delhi
  • Steamroller – Berlin
  • Kyoto

If you boot the ESXi 8.0 installer and it detects that you have an unsupported CPU, you will see the following error message.

The default behavior of the ESXi 8.0 installer is to prevent users from installing ESXi on a system that has a CPU that is not officially supported.

ProTip: With that said, there is a workaround for those that wish to forgo official support from VMware or for homelab and testing purposes, you can add the following ESXi kernel option (SHIFT+O):

allowLegacyCPU=true

which will turn the error message into a warning message and enable the option to install ESXi, knowing that the CPU is not officially supported and accept any risks in doing so.

I/O Device Support

Similarly for I/O devices such as networking, storage, etc. that are not be supported with vSphere 8, the ESXi 8.0 installer will also list out the type of device and its respective Vendor & Device ID (see screenshot above for an example).

To view the complete list of unsupported I/O devices for vSphere 8, please refer to the following VMware KB 88172 article for more information. I know many in the VMware Homelab community makes use of the Mellanox ConnectX-3 for networking, so I just wanted to call this out as that is no longer supported and folks should look to using either the ConnectX-4 or ConnectX-5 as an alternative.

ProTip: A very easy and non-impactful way to check whether your existing CPU and I/O devices will run ESXi 8.0 is to simply boot an ESXi 8.0 installer using USB and check whether it detects all devices. You do NOT have to perform an installation to check for compatibility and you can also drop into the ESXi Shell (Alt+F1) using root and no password to perform additional validation. If you are unsure whether ESXi 8.0 will run on your platform, this is the eaiest way to validate without touching your existing installation and workloads.

For those that require the use of the Community Networking Driver for ESXi Fling to detect onboard networking like some of the recent Intel NUC platforms, folks should be be happy to learn that this Fling has been officially productized as part of vSphere 8 and custom ESXi ISO image will no longer be needed. For those that require the USB Network Native Driver for ESXi Fling, a new version of the Fling that is compatible with vSphere 8 will be required and folks should wait for that to be available before installing and/or upgrading to vSphere 8.

USB Install/Upgrade Support

Last year, VMware published revised guidance in VMware KB 85685 regarding the installation media for ESXi which includes ESXi 8.0 and specifically when using an SD or USB device. While ESXi 8.0 will continue to support installation and upgrade using an SD/USB device, it is highly recommended that customers consider a more reliable installation media like an SSD, especially for the ESXi OSData partition. Post-ESXi 8.0, USB installation and upgrades using an SD/USB device will no longer be supported and it is best to have a solution now than to wait for that to happen, if you ask me.

If you do decide to install and/or upgrade ESXi 8.0 using SD/USB device, the following warning message will be presented before allowing you to proceed with the install or upgrade.

Hardware Platform Support

While this is not an exhaustive list of hardware platforms that can successfully run ESXi 8.0, I did want to share the list of systems that I have personally tested and hope others may also contribute to this list over time to help others within the community.

The following hardware platforms can successfully run ESXi 8.0:

• Intel NUC 5 (Rock Canyon)
• Intel NUC 6 (Swift Canyon)
• Intel NUC 8 (Dawson Canyon)
• Intel NUC 9 Extreme (Ghost Canyon)
• Intel NUC 9 Pro (Quartz Canyon)
• Intel NUC 10 Performance (Frost Canyon)
• Intel NUC 11 Performance (Panther Canyon)
• Intel NUC 11 Pro (Tiger Canyon)
• Intel NUC 11 Extreme (Beast Canyon)
• Intel NUC 12 (Dragon Canyon)
• Intel NUC 12 Pro (Wall Street Canyon)
• Supermicro E200-8D
• Supermicro E302-12D

VCSA Resource Requirements

With all the new capabilities in vSphere 8, it should come as no surprise that additional resources are required for the vCenter Server Appliance (VCSA). Compared to vSphere 7, the only change is the amount of memory for each of the VCSA deployment sizes, which has increased to an additional 2GB of memory. For example, in vSphere 7, a “Tiny” configuration would required 12GB of memory and in vSphere 8, it now will require 14GB of memory.

ProTip: It is possible to change the memory configurations after the initial deployment and from my limited use, I have been able to configure a Tiny configuration with just 10GB of memory without noticing any impact or issues. Depending on your usage and feature consumption, you may need more memory but so far it has been working fine for a small 3-node vSAN cluster.

Nested ESXi Resource Requirements

Using Nested ESXi is still by the far the easiest and most efficient way to try out all the cool new features that vSphere 8 has to offer. If you plan to kick the tires with the new vSAN 8 Express Storage Architecture (ESA), at least from a workflow standpoint, make sure you can spare at least 16GB of memory (per ESXi VM), which is the minimum required to enable this feature.

Note: If you intend to only use vSAN 8 Original Storage Architecture (OSA), then you can ignore the 16GB minimum as that only applies to enabling vSAN ESA. For basic vSAN OSA enablement, 8GB (per ESXi VM) is sufficient and if you plan to run workloads, you may want to allocate more memory but behavior should be the same as vSphere 7.x.

A bonus capability that I think is worth mentioning is that configuring MAC Learning on a Distributed Virtual Portgroup is now possible through the vSphere UI as part of vSphere 8. The MAC Learning feature was introduced back in vSphere 6.7 but was only available using the vSphere API and I am glad to finally see this available in the vSphere UI for those looking to run Nested Virtualization!

esxcli software vib install -v https://hostupdate.vmware.com/software/VUM/PRODUCTION/main/esx/vmw/vib20/nvme/VMW_bootbank_nvme_1.2.1.34-1vmw.670.0.0.8169922.vib

esxcli software vib install -v https://hostupdate.vmware.com/software/VUM/PRODUCTION/main/esx/vmw/vib20/vmware-esx-esxcli-nvme-plugin/VMware_bootbank_vmware-esx-esxcli-nvme-plugin_1.2.0.32-0.0.8169922.vib

reboot

Tüm işlemler bu kadar.

SSH login olun ve aşağıdaki kodu yazın.

sudo nano /etc/network/interfaces

text sayfası içerisinden ip adres ve gerekiyorsa gateway, netmask, dns ayarlarını güncelleyin.

CTRL + X ve Y tuşuna başarak sayfayı kaydedin.

sudo /etc/init.d/networking restart
yazarak network restart atın.

sudo reboot
yazarak sunucuyu restartlayın.

You can still configure RDP settings, but you’ll have to use Group Policy to do so. Just use these steps:

1. Launch “gpedit.msc“.
2. Navigate to “Computer Configuration” > “Administrative Templates” > “Windows Components” > “Remote Desktop Services” > “Remote Desktop Session Host“.

Here you can find group policy settings to set Licensing, Security, Connections, etc. You’ll notice these are the same settings you would find in the old Remote Desktop Host Configuration tool like “Limit number of connections”, “Set time limit for disconnected sessions” , and setting the licensing mode.

You don’t need to utilize Active Directory in your environment to use these settings on the server either.