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Daily Checklist VMware: Sensor Warnings when Monitoring ESX Host Server Hardware

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Daily Checklist: Sensor Warnings when Monitoring ESX Host Server Hardware Occasionally, sensors in PRTG show a warning status with the message “X elements not found” (or with another number) when monitoring ESX host server hardware. Though, the sensor worked correctly previously. This issue might appear when monitoring with the VMware Host Hardware Status sensor via SOAP, as well as it can be the case when monitoring the server via WBEM or SNMP. The warning message in PRTG indicates a not properly functioning CIM (Common Information Model) server on the ESX host. The monitoring result for the ESX server will be ‘unknown’ for all hardware devices in this case. Possible Solutions In order to get the CIM server working properly again and, thus, receive data with the affected sensor, please consider the following steps. They are ordered from ‘simple solution’ to ‘hard solution’, so try them step by step and check after each one if the corresponding sensor recieves the expect
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VMware: Real difference between VMware HA 4.x & vSphere 5.x

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Capability VMware HA 4.x vSphere HA 5.x Agents VMware HA in vSphere 4.x has AAM (Automated Availability Manager) agents VMware HA in vSphere 5.x has FDM (Fault Domain Manager) agents installed Cluster Members The first five hosts added to the cluster are designated as primary hosts, and all subsequent hosts are designated as secondary hosts. If a primary host is removed from the cluster, VMware HA promotes another (secondary) host to primary status. Each host in the cluster functions as a master host or a slave host. Only one master host exists per cluster and all other hosts are slave hosts. If the master host fails, is shut down, or is removed from the cluster a new election is held. Responsibilities Primary Hosts: Decide where to restart virtual machines. Keep track of failed restart attempts. Determine when it is appropriate to keep trying to restart a virtual machine Master Host: Monitors the state of slave hosts. If a slave host fails or
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Active Directory and Active Directory Domain Services Port Requirements

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The following table lists the port requirements for establishing DC to DC communication in all versions of Windows Sever beginning with Windows Server 2003 Protocol and Port AD and AD DS Usage Type of traffic TCP and UDP 389 Directory, Replication, User and Computer Authentication, Group Policy, Trusts LDAP TCP 636 Directory, Replication, User and Computer Authentication, Group Policy, Trusts LDAP SSL TCP 3268 Directory, Replication, User and Computer Authentication, Group Policy, Trusts LDAP GC TCP 3269 Directory, Replication, User and Computer Authentication, Group Policy, Trusts LDAP GC SSL TCP and UDP 88 User and Computer Authentication, Forest Level Trusts Kerberos TCP and UDP 53 User and Computer Authentication, Name Resolution, Trusts DNS TCP and UDP 445 Replicatio
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Linux and Unix: L1 & L2: System Administration Interview Questions

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1)  What is GRUB GNU GRUB is a Multiboot boot loader. It was derived from GRUB, the GRand Unified Bootloader, which was originally designed and implemented by Erich Stefan Boleyn. Briefly, a boot loader is the first software program that runs when a computer starts. It is responsible for loading and transferring control to the operating system kernel software (such as the Hurd or Linux). The kernel, in turn, initializes the rest of the operating system (e.g. GNU) 2) Explain Linux Boot Process Press the power button on your system, and after few moments you see the Linux login prompt. Have you ever wondered what happens behind the scenes from the time you press the power button until the Linux login prompt appears? The following are the 6 high level stages of a typical Linux boot process.
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Advance VMware HA interview Q & A

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Q1: Exp l a i n h o w re s t a rt of V M ’s i s h a n d l ed b y HA i n case o f a ma s ter E s xi Host f a il u re. An s : H A r e star t s VM’s a ft e r f ai lu re of a n E s x i ho s t . B u t t he t i me t a k e n by H A to re s t a rt VM’s i s di ff e r e nt i n c a s e of a s l a ve E s x i fa i lu re a nd m a ster E s x i fa i lu r e . W e will di s c u ss h e re t he ca s e wh e n ma ster E sxi ha s f ai l ed . In ca s e of a f ai lu re of a m a ster E s xi , r e start of V M ’s a re de l a y e d t i l l t he t i me a n e w m a ster i s e l ec t e d b e c a u se only a m a ster c a n p e r f orm VM r e star t . The t i m e l i ne i s ex pl ai n e d a s f o ll o w s: ·      T0 – M a ster f ai lu r e . ·      T1 0 s – M a ster e l ec t i on pro ce ss i n i t ia te d . ·      T2 5 s – New m a ster e le c t e d a n d r e ad s t he pro t ec t e d list. ·     T35s – New m a s
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