Ceyhun KIRMIZITAŞ

18Mar 2026 by Ceyhun Kirmizitas No Comments

What Happens to Shared Calendars After Exchange Hybrid Migration?

In Exchange Hybrid environments, shared calendar behavior after mailbox migration is often misunderstood. Many assume that calendar access breaks when a mailbox is moved to Exchange Online. In reality, the outcome depends on how permissions were configured before the migration. This article walks through a controlled scenario and shows exactly what happens. Scenario We use two users: buser01@onpremx.com bmuser01@onpremx.com Initial state: Both mailboxes are on on-prem Exchange Users can access each other’s calendars Step 1 – Test Default Behavior (On-Prem → On-Prem) Without assigning any permissions: Add calendar in Outlook Calendar is added successfully Only free/busy information is visible No subject or details This is expected. Default calendar permission: PowerShellAvailabilityOnlyAvailabilityOnly Step 2 – Check Existing Permissions Verify current permissions: PowerShellGet-MailboxFolderPermission bmuser01:\Calendar Get-MailboxFolderPermission buser01:\CalendarGet-MailboxFolderPermission bmuser01:\Calendar Get-MailboxFolderPermission buser01:\Calendar Typical result: No explicit…

15Mar 2026 by Ceyhun Kirmizitas No Comments

Reclaiming Space from Inflated Thin VMDK Disks After VM Export in ESXi

vSphere

After exporting several virtual machines from my ESXi environment, I noticed that datastore usage had increased significantly. Although the guest operating systems were using only a small portion of their virtual disks, the VMDK files appeared to occupy space close to their full provisioned size. For example, a virtual machine with a 100 GB thin-provisioned disk that was actually using only around 17 GB inside the guest OS appeared to consume almost the entire provisioned disk size on the datastore. This situation can quickly become problematic in environments where multiple virtual machines are exported or stored for later use. Datastores may appear nearly full even though the real data footprint is much smaller. Why Does This Happen? When virtual machines are exported (for example as OVF or OVA), thin-provisioned disks…

20Apr 2019 by Ceyhun Kirmizitas No Comments

Installing Arch Linux 2013.05.01 + KDE 4 in VMware Workstation 9

Linux, Video Tutorials

What is Arch Linux? Arch Linux is an independently developed general purpose GNU/Linux distribution. Development focuses on simplicity, minimalism. Arch Linux was founded by Canadian programmer Judd Vinet. Its first formal release, Arch Linux 0.1, was on March 11, 2002. Although Arch is completely independent, it draws inspiration from the simplicity of other distributions including Slackware and BSD. Arch Linux is one of my favorite GNU/Linux distributions, however it is not as easy to install as are other Linux distributions. In this video tutorial, we will see how to Install step-by-step How to Install Arch Linux 2020.09 + KDE Plasma Desktop + Apps + VMware Tools on VMware Workstation https://www.youtube.com/watch?v=moecil7aSKo&pp=ygU8QXJjaCBMaW51eCAyMDEzLjA1LjAxICsgS0RFIDQuMTAgaW4gVk13YXJlIFdvcmtzdGF0aW9uIDkuMC4y Hope you found it informative and useful. Any questions or comments are welcomed.

19Apr 2019 by Ceyhun Kirmizitas No Comments

How to Enable iSCSI and Adding an iSCSI Drive on Iomega StorCenter ix4-200d NAS

Storage

Enabling iSCSI on Iomega StorCenter ix4-200d iSCSI (Internet SCSI) is a method of creating a SAN (Storage Area Network) over a standard network (without having to rewire for Fibre Channel). With iSCSI, your StorCenter device will act as if it were a hard drive connected directly to your computer. The iSCSI page allows you to create iSCSI drives in your device and then allows your client device to communicate with the drives over a network. iSCSI is useful for transmitting large blocks of data over a network at a high speed. To access the iSCSI page, navigate to the Settings tab and click iSCSI. 1- To enable iSCSI, check Enable iSCSI. When the checkbox is checked, configuration for Internet Storage Name Service (iSNS) and mutual authentication is displayed. 2- To…

19Apr 2019 by Ceyhun Kirmizitas No Comments

Installing VMware Tools in Debian 7.0 Wheezy

Linux, Video Tutorials

What is VMware Tools VMware Tools is an optional, free set of drivers and utilities that enhances both the performance of a virtual machine’s guest operating system and interaction between the guest and the host. From time to time I find clients have not installed the VMware tools in their virtual machine’s (VM) operating system. Installing VMware Tools in the guest operating system is vital. Although the guest operating system can run without VMware Tools, you lose important functionality and convenience. We'll install VMware Tools in Debian 7.0 Wheezy in the following video tutorial. How to Install VMware Tools on Debian 8.5 Jessie Step by Step Tutorial https://www.youtube.com/watch?v=1A5dmrvdkrU&pp=ygVCSW5zdGFsbGluZyBWTXdhcmUgVG9vbHMgaW4gRGViaWFuIDcuMCBXaGVlenkgbGludXggdmlkZW8gdHV0b3JpYWxz Hope you found it informative and useful. Any questions or comments are welcomed.

18Apr 2019 by Ceyhun Kirmizitas No Comments

Install and Configure Primary (Master) BIND DNS Server – RHEL 6 – CentOS 6

Red Hat - CentOS - Fedora, Video Tutorials

BIND DNS Server is a widely used DNS Server. Because domain names are alphabetic, they are easier to remember. So if we will browse the Internet we don’t need to remember IP addresses. For example, the domain name www.yourdomain.com might translate to 192.168.0.1. This video tutorial will show you how to setup and configure Primary (Master) BIND DNS Server on RHEL 6.x or CentOS 6.x: Install BIND Configure BIND Create primary DNS zone for linuxlab.local domain Add NS, A, MX records to zone Steps: 1. Install BIND yum install bind 2. Enable named service chkconfig named on 3. Edit /etc/named.conf 4. Start named ( BIND) service service named start 5.Edit /etc/named.conf 6. Copy /var/named/named.localhost cp named.localhost linuxlab.local 7. Edit /var/named/linuxlab.local $TTL 1D @ IN SOA ns1.linuxlab.local. hostmaster.linuxlab.local. ( 0 ; serial 1D…

18Apr 2019 by Ceyhun Kirmizitas No Comments

How to Install VMware Tools in Ubuntu 13.04 (Raring Ringtail)

Linux, Video Tutorials

VMware Tools is an optional, free set of drivers and utilities that enhances both the performance of a virtual machine’s guest operating system and interaction between the guest and the host. From time to time I find clients have not installed the VMware tools in their virtual machine’s (VM) operating system. I find it more often in Linux VMs than Windows. Installing VMware Tools in the guest operating system is vital. Although the guest operating system can run without VMware Tools, you lose important functionality and convenience. In this video we'll install and configure VMware Tools in Ubuntu 16.04 LTS https://www.youtube.com/watch?v=F5WaWIfi8f8

17Apr 2019 by Ceyhun Kirmizitas No Comments

Installing Red Hat Enterprise Linux 6.4 (RHEL 6.4) in VMware Workstation 9.0.2

Linux, Video Tutorials

Red Hat Enterprise Linux (RHEL) is a Linux-based operating system from Red Hat designed for businesses. RHEL can work on desktops, on servers, in hypervisors or in the cloud. Red Hat Enterprise Linux contains the Linux kernel as well as some applications for performing certain tasks. Like all Linux distributions, RHEL is open source. Thus, people can view its source code, download it and make their own customized versions. Some of the notable Linux distributions that are actually derived from RHEL include CentOS, Oracle Enterprise Linux, and Scientific Linux. People who subscribe to RHEL can download the installer for free but have to pay for support. Special editions of RHEL are available for academic institutions who are willing to pay a smaller fee to use the relatively more stable RHEL…

17Apr 2019 by Ceyhun Kirmizitas No Comments

Installing Zimbra 8.0.4 on CentOS 6.4 X64 – RHEL 6.4

Video Tutorials, Zimbra

Zimbra Collaboration Suite (ZCS) is a groupware product created by Zimbra. It is widely used in the world. Users can share folders, contacts, schedules and other things, using a very rich web interface. In this tutorial, I will explain installing Zimbra Collaboration Server 8.0.4 - Open Source Edition on CentOS 6.4 X64 or RHEL 6.4 Installation Steps 1. yum update - Update your system 2. Install prerequisites yum install sudo sysstat libidn gmp libtool-ltdl compat-glib vixie-cron nc perl libstdc++.i686 3. Modify /etc/hosts file and Also, be sure to setup a DNS MX record in your zone file 127.0.0.1 localhost localhost.localdomain #::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 192.168.0.20 centos01.linuxlab.local centos01 4. Disable start-up services 4a. chkconfig postfix off 4b. service postfix stop 4c. chkconfig sendmail off 4d. service sendmail stop 5. /etc/sudoers…

16Apr 2019 by Ceyhun Kirmizitas No Comments

Introducing VMFS 5: What you need to know in a nutshell – vSphere 5

VMware

It?s new, and it?s good :) VMFS-5 increases limits (without increasing extents) to 64TB. It enables 2TB+ RDMs. It uses a common allocation size of 1MB. It increases the small block allocations available for total use. It is a dependency for SCSI UNMAP It uses the VAAI HW accelerated locking more extensively. Be aware: While it can non-disruptively be upgraded from VMFS-3 to VMFS-5 - if it were my environment - I would tend to create new datastores and svmotion.