Category: Data Center

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Operating System

Oracle Linux Yum Server

Yum Server Sometimes, you need to update single package on your Linux (Oracle – RedHat) and you have to search and find RPM file on this regard or compile the package from its source code. But we are talking enterprise Linux servers that you can’t accept any risk of installing miscellaneous or unreliable package on your server. So you need to have safe and secure source for installation or upgrade. Maybe, you are thinking about YUM! Yes, you can update your application by run Yum but if your server has no connection to internet! There is many solution for updating Linux packages but we are talking about a single application and some special conditions. Hopefully, Oracle has a service that called “Yum Server” and the service is free for use by anyone. Oracle Yum Server offers you a free and convenient way to install the latest Oracle Linux packages as well as packages from the Oracle VM installation media via a yum client. Please consider that this service deliver no support to you and just you can download updated packages from that.

Intel VT Issue 0

How To / Server Virtualization

ESXi host fails with a PSOD due to an Intel Virtualization Technology!

I have read a KB on VMware Knowledge Base and it says that an Intel Virtualization Technology can be cause of PSOD. This is little funny because ESXi will be affected by wide range of Intel Xeon processor family: Intel® Xeon® Processor 55xx Series Intel® Xeon® Processor 56xx Series Intel® Xeon® Processor 65xx Series Intel® Xeon® Processor 75xx Series Intel® Xeon® Processor E5-1400 v2 Product Family Intel® Xeon® Processor E5-1600 v2 Product Family Intel® Xeon® Processor E5-1600 v3 Product Family Intel® Xeon® Processor E5-2400 Product Family Intel® Xeon® Processor E5-2400 v2 Product Family Intel® Xeon® Processor E5-2600 Product Family Intel® Xeon® Processor E5-2600 v2 Product Family Intel® Xeon® Processor E5-2600 v3 Product Family Intel® Xeon® Processor E5-2600 v4 Product Family Intel® Xeon® Processor E5-4600 Product Family Intel® Xeon® Processor E5-4600 v2 Product Family Intel® Xeon® Processor E5-4600 v3 Product Family Intel® Xeon® Processor E5-4600 v4 Product Family Intel® Xeon® Processor E7-2800 Product Family Intel® Xeon® Processor E7-4800 Product Family Intel® Xeon® Processor E7-8800 Product Family Intel® Xeon® Processor E7-8800/4800/2800 v2 Product Families Intel® Xeon® Processor E7-8800/4800 v3 Product Families Intel® Xeon® Processor E7-8800/4800 v4 Product Families There is a workaround for preventing the problem and PSOD on server but VMware...

VMware LABS – Updated Fling 0

Free Tools / Server Virtualization

VMware LABS – Updated Fling

Three flings are updated by VMware engineers and published during this week and past week. HCIBench This fling is a “Hyper-converged Infrastructure Benchmark” tools and if you have vSAN in your environment, this fling is very useful for you. Changelog   Increased Timeout value of client VM disk from 30 seconds to 180 seconds. Disabled client VM password expiration. Disabled client VM OS disk fsck. Set Observer interval to 60 seconds to shrink the size of observer data. Fixed PCPU calculation. Created link directory of /opt/automation/logs, user will be able to review the testing logs in http://HCIBENCH/hcibench_logs/ Increased the RAM of HCIBench from 4GB to 8GB to avoid running out-of-resource issue.

ESXi 5.5, 6.x IOPS Limit Not Working – Disk.SchedulerWithReservation 1

How To / Server Virtualization

ESXi 5.5, 6.x IOPS Limit Not Working – Disk.SchedulerWithReservation

Last week, we went limit some our machines IOPS but we saw the limitation is not working on our machines, after searching the issue on VMware KB, we found an KB (2059192) that explain an known issue on ESXi 5.5 and ESXi 6. It seems, disk IO scheduling model has been changed on the platforms and it’s cause of the issue. But the solution is so simple, just you need to change an ESXi’s parameter: Revert the disk I/O scheduler to an earlier version by using the vSphere Web Client In the vSphere Web Client, edit the Disk.SchedulerWithReservation parameter in the Advanced System Settings list for the host. Navigate to the host. On the Manage tab, click Settings and click Advanced System Settings. Locate the Disk.SchedulerWithReservation parameter.Note: You can use the Filter or Find text boxes to find the parameter easily. Click Edit and set the parameter to 0. Click OK. Revert the disk I/O scheduler to an earlier version by using an ESXCLI command In the ESXi Shell to the host, run this console command: esxcli system settings advanced set -o /Disk/SchedulerWithReservation -i=0 There is no need to reboot or anything else. The configuration will be applied immediately.

KickStart Menu 2

Operating System

Linux KickStart – Automated Installation

Kickstart installations offer a means to automate the installation process, either partially or fully. Kickstart files contain answers to all questions normally asked by the installation program, such as what time zone you want the system to use, how the drives should be partitioned, or which packages should be installed. Providing a prepared Kickstart file when the installation begins therefore allows you to perform the installation automatically, without need for any intervention from the user. This is especially useful when deploying Red Hat Enterprise Linux on a large number of systems at once. Kickstart files can be kept on a single server system and read by individual computers during the installation. This installation method can support the use of a single Kickstart file to install Linux on multiple machines, making it ideal for network and system administrators. All scripts and the log files of their execution are stored in the /tmp directory to assist with debugging installation failures. Note You must read your distribution documents about fresh installation and upgrading current OS because some distributions don’t support upgrading via KickStart. How Do You Perform a Kickstart Installation? Kickstart installations can be performed using a local DVD, a local hard drive, or via NFS, FTP,...

Oracle VM – Virtualization Modes or Domain Types – Part 1 0

Server Virtualization

Oracle VM – Virtualization Modes or Domain Types – Part 1

Introduction Oracle VM introduced two main modes or domain types: Paravirtualized (PVM):A virtual machine with a kernel that is recompiled to be made aware of the virtual environment. Runs at near native speed, with memory, disk and network access optimized for maximum performance.Paravirtualized guests use generic, idealized device drivers, which are part of the guest’s OS. The I/O operations using these generic device drivers are mapped to the real device drivers in dom0. The generic, abstracted drivers in the guest seldom change and provide excellent guest stability. The dom0 domain, alternatively, can use the native hardware vendor drivers, and the guests can safely migrate to another dom0 with slightly different drivers. For other resources such as CPU and memory, paravirtualized kernels make special “hypercalls” to the Xen hypervisor. These hypercalls provide better performance by reducing the number of instructions and context switches required to handle an incoming request. By contrast, on an emulated (hardware virtualized) guest, driver requests engage the guest’s interrupt handler, increasing the I/O operation overhead. Hardware Virtualized Machine (HVM):A hardware virtualized guest runs on the virtualization platform as it would on a physical host. Because the device drivers of the hardware virtualized guest are emulated, dom0 must...

Oracle VM 0

Server Virtualization

Oracle VM Server – Configuration Limits for Release 3.4

Today, virtualization is under development by many companies and big companies trying to have their virtualization solution. Oracle VM is Oracle virtualization platform that it’s based on Xen hypervisor. You may know that any hypervisor has some limitations and configuration maximums and you should consider the limitation when you are deploying infrastructure or creating virtual machines. Oracle VM Manager Maximums em x86 Maximum SPARC Maximum Oracle VM Servers in a server pool (unclustered) 64 64 Oracle VM Servers in a server pool (clustered) 32 32 Number of servers 256 (16 servers * 16 server pools) 256 (16 servers * 16 server pools) Number of server pools 16 16 Number of configured virtual machines 5120 (20 virtual machines * 256 servers) 5120 (20 virtual machines * 256 servers) Number of running virtual machines 2,560 (10 virtual machines per server * 256 servers) 32768 (128 virtual machines per server * 256 servers) Fujitsu M10-4S, this limitation is 65536 (256 virtual machines per server * 256 servers) Oracle SPARC M-series servers, this limitation is 128 virtual machines per server * the number of physical domains (PDoms). Each physical domain acts as its own server with its own set of logical domains.  

Check CPU, Memory and Storage OverCommitment – PowerCLI 1

Server Virtualization / How To

Check CPU, Memory and Storage OverCommitment – PowerCLI

What’s OverCommitment? OverCommitment means virtual machines can use more resources than physical resources. CPU OverCommitment means you can create virtual machines with vCPU more than your server physical CPU, for example: Your server has two socket and each socket has 12 cores and also hyper-threading is enable, so you have 24 physical cores and 48 logical cores totally. But you can create and power on some virtual machines that those virtual machines have more than 48 cores totally. Memory OverCommitment means your virtual machines can use more memory than the physical machine (the host) has available. For example, you can have a host with 2GB memory and run four virtual machines with 1GB memory each. In that case, the memory is overcommitted. Advantages vs Disadvantages With OverCommitment, you can run more virtual machines but if you don’t have sensitive machine. If you have critical services on virtual machines, you need take care about OverCommitment because it can decrease your machines performance. How Take Care? You know, there is many native and third-party applications for monitoring vSphere environment but if you don’t have budget for buy monitoring software, you can use PowerCLI! There is a free PowerCLI module that you can...

Hewlett Packard Enterprise Information Library 0

Server Hardware

Hewlett Packard Enterprise Information Library

Introduction Many of large companies around the world using HPE products to makes their datacenters. HPE produces server, storage, network devices and some others infrastructure equipment and all of them have technical documentation, user guides and maintenance guides. Also anyone who are using the equipment need to access to the documentation. Hewlett Packard Enterprise has provided an online library that they called it “Hewlett Packard Enterprise Information Library”. What information can I find? Actually, any information about your devices and software is available on this library, you can find and download Release Notes, User Guides, White Paper and others documentation in PDF or HTML format and also you can choose different languages for the documents. Also documents are categorized and you can choose your device according to different solutions. After choose the above options to filtering your results, you can find the related documents under the “Information Types / File Types / Languages” section. There is no need to search Google to find HPE products and devices documents anymore.  

Hardening Guide 1

Server Virtualization / Security

VMware vSphere Hardening

Today, many companies have virtualized farms for their server infrastructure or desktop infrastructure and cloud services. The companies have critical information on their virtualized farms and keeping safe them is one of big concerns. Big companies or even small companies have security teams and the teams tries to keeping secure the environments in different layers. Most of the security products are working on physical layer or network and application layer but what about Hypervisor layer? vSphere Hardening VMware publishing a hardening guide for each vSphere version to help administrator to keep their environments more secure. vSphere hardening guides are available in the below link as Excel files: Download – Hardening Guides Previously, VMware had published an application to analyzing your vSphere environment and report you any security issue according to hardening guides. VMware Sphere Compliance Checker was available up to vSphere 5.5 and that’s not available for vSphere 6.x but you can use “VMware vRealize Configuration Manager” on this regard. Anyway, you can check and change security configurations accordion to hardening guides on your servers manually.

Network Ports in Horizon 7 0

Desktop Virtualization

Network Ports in Horizon 7

VMware has updated “Network Ports in Horizon 7” and you can download it as a PDF file. You can find all protocols, port numbers and Horizon 7 components connections in this diagram. It helps you to understand communications between components and design your network infrastructure when you want to deploy Horizon 7 in you environment.It’s available on this link: Download

Veeam Backup Replication Best Practices 9U2 1

Backup & Replication

Veeam Backup & Replication Best Practices

Veeam has published a guide for Veeam Backup & Replication past week. The guide contains best practices that it will help you to deploy your backup solution according to your environment with best performance. You can download the guide from: https://www.gitbook.com/book/poulpreben/veeam-backup-replication-best-practices/details Update: The book has been updated and it’s covering Veeam Backup & Replication 9 U2

ESXi Reliable Memory Technology 0

Reviews / Server Virtualization

ESXi Reliable Memory Technology

VMware has introduced new feature for kernel protection against memory error in ESXi. VMware called the new feature: Reliable Memory Technology or RTM. The feature is one of new features in ESXi 5.5! ESXi use a zone of memory that it’s more reliable than other offsets of memory, so risk of PSOD will be reduced. Also when part of memory has error, ESXi will stop to using the part of memory. There is some other technique against memory corruption or memory health error such as memory mirroring but Reliable Memory Technology can help you on this regard without loosing half of your memory capacity. Because memory mirroring is just like to RAID 1 on hard disks. Dell has introduced another feature on its server by using Reliable Memory Technology and called the new feature: Fault Resilient Memory or FRM. Fault Resilient Memory will provide “Fault Resilient Zone” and ESXi will put its kernel to the zone. The features can protect ESXi kernel and VMs as well. So if you have critical service on a VM, you can force ESXi to keep its memory on RTM or FRM zone to avoid memory error and down time for the machine. You can configure...

osjs 0

Reviews / Desktop Virtualization

What is web desktop?

This century has begun with a big jump in portable devices and gadgets technology. Few years ago, we had to carry our big laptop for attending to our meetings or … . Today, we have smart phones and we can do anything on them.But those are not powerful like laptops or desktops and they have small screen and they have many limitation yet. Today, we keeping our data (Important data) on cloud storage services and our portable devices become smaller. Today, we are using virtualization technology for reduce our costs and we are implementing our virtual data centers around the world. Today, we are using virtual desktops instead of physical desktops and we have some protocols for connecting to them remotely and have experiences same as physical desktops even from a web browser. This is a gift from virtualization leaders to us. But virtual desktops are still expensive and needs to modern hardware. There is another solution and you can have your web desktop. A web desktop or webtop is a desktop environment embedded in a web browser or similar client application. A webtop integrates web applications, web services, client–server applications, application servers, and applications on the local client into...

fcoe disable 005 0

Server Hardware

FIP VLAN ID unavail. Retry VLAN discovery

I was faced with the below log in ESXi “vmkernel.log” and I want to explain the issue and share the solution with you: fip: fcoe_ctlr_vlan_request() is done fip: host7: FIP VLAN ID unavail. Retry VLAN discovery First, I want to say that this is an issue and not a serious problem and you can ignore it but the log will be repeated continuously. Now, what is the root cause? The root cause is using CNA adapters as network adapter. As you may now, CNA (Converged Network Adapter) is a network adapter that you can use its port as network port or FCoE port for storage connectivity. FCoE is enabled by default on all ports and ESXi trying to discover FCoE VLAN and targets when discover the FCoE feature on the ports. When ESXi couldn’t discover FCoE connection, force the driver to find and discover it again. Now, what is the solution? There is two solutions that I recommend use the second solution because removing driver or any part of ESXi is not recommended. As the first solution, you can disable FCoE feature on the ports and remove the driver from ESXi: Determine which vmnics have FCoE capability esxcli fcoe nic...