Questions tagged [failover]

In computing, failover is automatic switching to a redundant or standby computer server, system, or network upon the failure or abnormal termination of the previously active application, server, system, or network. Failover and switchover are essentially the same operation, except that failover is automatic and usually operates without warning, while switchover requires human intervention.

In computing, failover is automatic switching to a redundant or standby computer server, system, or network upon the failure or abnormal termination of the previously active application,server, system, or network. Failover and switchover are essentially the same operation, except that failover is automatic and usually operates without warning, while switchover requires human intervention.

Systems designers usually provide failover capability in servers, systems or networks requiring continuous availability and a high degree of reliability. At server level, failover automation usually uses a "heartbeat" cable that connects two servers. As long as a regular "pulse" or "heartbeat" continues between the main server and the second server, the second server will not initiate its systems. There may also be a third "spare parts" server that has running spare components for "hot" switching to prevent downtime. The second server takes over the work of the first as soon as it detects an alteration in the "heartbeat" of the first machine. Some systems have the ability to send a notification of failover.

Some systems, intentionally, do not failover entirely automatically, but require human intervention. This "automated with manual approval" configuration runs automatically once a human has approved the failover.

Source: wikipedia

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vSphere NIC Teaming - Any reason for Active/Standby?

We're using ESXi and I'm wondering about the "NIC Teaming" options for our vSwitches. On a particular vSwitch with 2 NICs, is there any GOOD reason for configuring a NIC as Active and the other as Standby?. I always use Active/Active scenarios…
Craconia
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NIC Active/Passive bonding with priority

I will configure a bond of three NIC's. I want to define which one will be first used and which NIC will be used as the second and third NIC when failover is done. Is this possible? Thanks
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How to achieve redundancy across data centers?

I have a LAMP server with a lot of hardware redundancy built in. I am not worried about the server becoming unavailable. What I am worried about, however, are potential network issues in the data center the server is in. What I would like to have is…
BrandonBT
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Failover Internet connection?

In my Linux server i have three network cards. The eth0 card is connected to ISP1, the eth1 card is connected to LAN and the eth3 card is connected to ISP2. What i want to do is to automatically use eth3 as Internet connection if the eth0…
ez_brian0
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Exchange 2010 DAG Automatic Failover Testing/Issue. Not always automatically failing over to healthy DB copy depending on the way mounted server wrecks

Ok I've got 2 exchange 2010 servers that run client access/hub transport/mailbox roles and one exchange 2010 server running just client access/hub transport roles and acts as my bridgehead. The two mailbox servers are running one database setup in…
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synchronizing storage servers

we have a storage server, with currently an amount of about 20TB of media files which we want to synchronize with a second storage server, for backup and fail-over. the facts are: we're storing currently about 9.000.000 files file sizes from…
harald
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Additional Domain Controller Failover and Failback

I have installed a DC – Let’s call it as DC1 I have installed a Second DC using (Additional Domain Controller for an existing domain controller option) – Let’s call it as DC2 Can anyone tell me: 1) If DC1(PDC) goes down, will DC2 (ADC) take over…
murad
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Cheap clustering for SQL server

Does anyone know of a way to simulate a clustered SQL server solution? We obviously don't want to spend a lot of money prototyping the idea, but we have quite a few PCs available. I was just wondering if there was any way I could fool SQL server…
RobertTheGrey
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Why aren't inherited scope options replicating between Win2019 DHCP servers in a failover config?

I have 2 Win 2019 DCs, both running DHCP servers with a scope configured for failover. If I explicitly set scope options on one, they properly replicate to the other server. But options inherited from the server options do not replicate (nor do…
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Redundant network connections for website

We are in the process of building a new secure web application for our company, and are looking at options for ensuring redundancy in our data center. We don't have a lot of money, but have relatively high bandwidth requirements, so have considered…
Beep beep
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How to set up tcp check with keepalived?

Trying to set up HA bastion servers. Failover, load balancing is not needed. Two servers running debian. bastion01 and bastion02. 192.168.0.10 and 192.168.0.11. Floating IP is 192.168.0.12. I started out with these configs: bastion01: global_defs { …
cat pants
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CTDB Samba failover not highly available

TL;DR Failing a node in a ctdb + samba cluster while interacting with a share interrupts share connection. here and here state there is work in progress to make this possible here states it is already possible with Samba 3.0 (currently using…
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Toggle postfix on and off

There's probably an answer to this already, but I just can't figure out how to search for it correctly. Situation: We have a failover situation for two nodes, using keepalived, passing a floating IP between them. The main purpose of the nodes is to…
Ross Presser
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How does High Availability work?

I don't understand how to setup a failover for my quite simple scenario. I am building a service gateway for API. What I want to have is two servers hosted in different datacenters. And I simply want the user to be able to access the service even if…
Wapac
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How to recover from switch failure?

Suppose there is only one switch within a system and it is connected to a bunch of machines to form a network. If this switch goes down, the entire network goes down. Chances of this happening are unlikely. I would like to know... what are the ways…
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