High availability is an architectural consideration often involving degrees of redundancy to insure availability in case of system or component failure.

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Clustered file systems as XenServer storage

I want to use shared storage for a XenServer environment with 4 host servers which are running various VMs under XenServer. Planning to use 2 extra servers as storage with high availability of some ...
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0answers
110 views

Fence node in apache traffic server

I'm currently looking into Apache Traffic Server as a tool for providing better availability of web services. But looking at the manual I can't see any reference to how I can pro-actively fence a ...
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1answer
675 views

Using LVS (Linux Virtual Server) for doing DNS HA

I have been trying to create an LVS DNS HA using CentOS 6.x: Piranha GUI to configure the DNS Pulse is the HA heart of CentOS LB IPTables to configure marks on the packets since DNS uses TCP and UDP ...
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1answer
368 views

which high availability model to choose for website (nginx/mysql)

We have 5 physical servers. All are identical. 16 gb ram, 4x146 10k sas in raid 10. So, we need high availability. Current plan is following: 2 boxes with Heartbeat for load balancing. At this ...
2
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1answer
179 views

VPS hosting with IP failover across datacenters

Is there any VPS hosting that would allow IP failover (or remapping) across different datacenters ? The only one I aware of is EC2 with their Elastic IP. What I'm trying to achieve is to have servers ...
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193 views

network mount across WAN [closed]

I have 2 networks separated by a WAN (25/25 fiber optic VPN). I would like to provide some files to both servers on networks via NFS (and Samba for the desktops, but that's on a per-site basis). some ...
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0answers
640 views

Windows 2008R2 RemoteAPP Failover

I'm trying to setup 2 remoteapp servers with a bit of fail-over in the design. I keep running into a few dead ends where there is no load balancing... or connections take a ridiculous amount of time ...
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1answer
445 views

Clustering on cloud/VPS providers

I'm wondering if anyone can give some clustering recommendations to me. I'm currently on Linode, which I'm impressed and happy with, but they (along with just about every other VPS provider I know of) ...
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1answer
73 views

Performance issue when configuring non-HA VM in cluster

A quote from the Technet Planning for Highly Available Virtual Machines Important It is recommended that you not deploy virtual machines that are not highly available on your host clusters. ...
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6answers
249 views

Use two website hostings for better availability

I have two VPS servers from two different hosting companies. I want to make some fallback to second VPS if first is not available (preferably automatic). I understand that if I have a single ...
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7answers
4k views

How to deploy web application for 2 million users?

I've been tasked with figuring out how to do a large scale deployment for a high availability, high traffic, dynamic, flash based web application. There is a good possibility that this application can ...
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3answers
72 views

If my DNS is a VM with HA do I need a secondary?

Same question would apply to mail server - if I have these running as VMs with failover / HA do I need to run a secondary / backup for either? This is a relatively small site (< 50 machines) so ...
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5answers
2k views

Free DNS software with failover support? [closed]

I'm looking for DNS software that can accomplish the following: Check health of all A records at set intervals If server is unresponsive after multiple successive checks, replace A record with a ...
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4answers
220 views

Configuring DNS to serve pages from multiple servers for a single domain

I have some really high-availability web page content that needs to be online 24x7. So instead of relying on a single server I was wondering if I could handle one domain name with multiple servers? ...
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2answers
292 views

Linux High Availability

I have two Linux Active/Passive nodes on which i have the same simple processing application(not webapp). I just need to have a HA cluster when one machine is down the application on the second takes ...
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3answers
150 views

How to set up an event website?

For my work, I need to set up an event website. The site will be up to 2 or 3 months during the campaign. The site needs to be stable and have high availability, especially during the rush hours. ...
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2answers
2k views

Getting started with KVM coming from Vmware

In order to test new ideas and reduce cost I would like to test KVM. I think Vmware has these 3 things which are valuable: - HA which restart VMs (Virtual Machines) in other hosts when a Hardware ...
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4answers
1k views

Server CPU spikes suddenly and becomes unusuable - Tips to monitor/analyze this?

my server has been going down over the last 24-48 hours, CPU spikes from 15% to 100% and server becomes unusable and all my sites go down as a consequence of it. Any tips on how I could track what is ...
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4answers
748 views

Low cost solution to http loadbalancer single point of failure?

I have many low end atom servers for a startup project, each server have a few public ip addresses (no private network). I'm currently in the process of making it failsafe. There now is a load ...
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3answers
2k views

SAN/NAS with high availability?

I have two servers that I plan to use for storage. Each of them has a few SATA disks directly attached. I want the storage to be available even if one of the storage servers is down (preferably the ...
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6answers
657 views

Windows Server 2003 Availability / Uptime

I'm looking at putting together a support SLA. As a base line I'd like to know roughly what sort of percentage availability I should expect from a non-clustered Windows 2003 Server. Assumptions are ...
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3answers
746 views

MySQL / InnoDB replication: how to perform crash recovery?

How do I perform crash recovery in a MySQL/InnoDB Master-Slave asynchronous replication setup? Specifically: If a slave crashes, how do I make it syncs up with the master after I bring it back up? ...
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6answers
991 views

Will the OS crash if the system partition can't be access for a short period?

An operating system is installed in a virtual machine environment, such as VMWare or KVM. A network shared disk volume (e.g., iSCSI disk) is used as the OS system partition. Heavy traffic is running ...
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2answers
244 views

Options for sessions handling in IIS

What options are there for session handling with a modern .NET IIS Web architecture? I understand that IIS' native session support loses sessions upon restart. Furthermore, Microsoft recommends ...
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3answers
615 views

How should I perform database maintenance on a 24x7 system

I'm a software developer who inherited a part-time DBA role. I'm responsible for an application backend by a small, high-volume 24x7 database on SQL Server 2008. While there's other stuff in the DB, ...
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5answers
918 views

High Availability iSCSI Target Options

I have two servers (Intel Xeon) with running ESXi on them. There are about 70 clients in the network (16 thin clients among them). We've got pretty large data storage (it's about 100TB). We're using ...
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2answers
492 views

hosting a website on multiple hosts

Is there a way to host a website on multiple hosts. exactly the same site, for example on hosting companies HostingABC and HostingDEF? In case there is ever a problem with HostingABC (either a ...
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4answers
5k views

NFS v4, HA Migration, and stale handles on clients

I'm managing a server running NFS v4 with Pacemaker/OpenAIS. NFS is configured to use TCP. When I migrate the NFS server to another node in the Pacemaker cluster, even though the metadata is ...
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2answers
57 views

How to create a redundent webserver using virtual machines

I would like to create a fail-over web server using one physical box and 2 virtual instances. What I am aiming for is the host OS monitors performance of a web server running in a virtual machine (ie ...
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1answer
228 views

ssh host key management between ha hosts

We have a setup with 2 Redhat-based servers which are both ha hosts behind a virtual ip. 192.168.0.3 dataserver (virtual ip) 192.168.0.1 dataserver_ha1 (physical server) 192.168.0.2 dataserver_ha2 ...
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1answer
440 views

Is there an ideal filesystem type for the MySQL database directory (/var/lib/mysql)?

I've used ext3 and ext4 in the past with no issues, but I've seen a lot of installations on XFS as well. What are the advantages of XFS vs ext4 vs ?? with respect to the /var/lib/mysql directory? ...
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1answer
829 views

Best RAID setup for DRBD

I would like to setup a two nodes PROXMOX cluster with DRBD storage. The nodes will be connected by gigabit ethernet. What would be the best storage setup in terms of reliability, performance and ...
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2answers
450 views

Convert HyperV Servers in to HyperV Cluster

We have 2 Hyperv Servers and a SAN. When they were configured, High Availability wasn't on the horizon. But it is now. Can I convert the current servers in place to use Failover Clustering? Or ...
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2answers
434 views

High Availability without IP Failover?

Are there strategies or techniques to create HA environment when IP failover isn't available? I'm reading a guide at Linode's library which describes exactly what I want to do, but I'm not sure my ...
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2answers
499 views

Exchange 2010 mailbox server role on a secondary dc - what is your opinion

I'm looking at the database availability groups in regards to creating a constant replication of the mailbox database. Here are three options I'm thinking of (and sorry if I'm wrong with my ...
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4answers
735 views

Most suitable high availability solution

My company is hosting a website in a server with IIS, SQL Server and a 3rd party windows service (written in C#, source code available for amendments). We bought a new identical server, composed by: ...
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1answer
693 views

All of ESX4 hosts not responding after rebooting vCenter server

I'm constructing 5ESX+a vCenter serv. I'm testing FT on the system. Today vCenter OS (W2008) demanded system reboot. After rebooting vCenter Serv. All of ESX hosts have alert icon. end indicate "not ...
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2answers
140 views

SQL 2008 Clustering

I need to configure SQL or Windows 2008 Clustering to get HA with no packet loss. I configure my SQLcluster, but when I restart one node, I lose one ping. I try to lose no ping so that my query will ...
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3answers
174 views

How to mirror server with 150 GB of data

I have a linux server whic is used as web/file/svn/sql server. It is accessed by 100 machines for storing their code files on this server(svn/code/mysql). The OS is on a 80 GB HDD. The data is on ...
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3answers
1k views

Shared PHP Sessions in Load Balanced httpd environment

I have two httpd servers running PHP on RHEL 5.7. Initially I was sharing PHP sessions between the servers using a common NFS share that was hosted on a third server. This was causing slow downs and ...
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3answers
2k views

ucarp: promote slave to master

I have got ucarp working on my two ubuntu servers. Apache, Postfix, Dovecot are working in HA mode so if one host goes down the other automatically takes over. My first problem is that I don't know ...
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3answers
4k views

How are you supposed to setup UCARP in CentOS?

I have UCARP working but the documentation is confusing and I've found at least 3 different ways suggested in blogs (these are old and don't all seem to work). I currently have ucarp- lines added to ...
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3answers
410 views

High availability for Windows Service under Windows Server 2003

I have a following situation: I need to deploy a windows service that listens for incoming request on tcp port (basically WCF service). I have a High Availability requirement - the service must be ...
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1answer
3k views

Exchange 2010 DAG + VMWare HA = no support?

We currently have an Exchange 2003 clustered environment (two machine cluster) that we're looking to upgrade to 2010. We recently purchased a VMWare virtualization environment (three Dell R710's with ...
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3answers
794 views

Resilient Linux Mail Server Setup

How would people design a resilient mail server setup with Linux? On an application level what the system needs to provide is both an incoming and outgoing mail service (i.e. SMTP & IMAP), along ...
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3answers
252 views

170 virtual machines HA requirements

my questions is : if i need to deploy 170 virtual machines and i need HA. is it possible to deploy all 170 vistual machines on one ESX host and in case one ESX host is down. all virtual will migrate ...
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1answer
583 views

Could a Geo-DNS create availability issues?

Geo-DNS can be used to balance traffic across data-centers. I found this (old) article where it is described why Geo-DNS implies availability issues if one of the IPs (data centers) goes down. Could ...
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6answers
252 views

SQL Server 2000 High Availability

How do you implement high availability on SQL Server 2000? Are there any 3rd party tools out there or any other ideas?
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77 views

Multi domain server with dedicated SSL's HA

I am hosting a server with 150 domain names (websites), each of the ssl's requere dedicated IP address. So server windows 2008, with 150 IP addressees and 150 websites. I need to have high ...
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3answers
77 views

Webserver failover with VMs on Two esxi 5.1

I have two server on datacenter with two websites abc.com, cde.com, and my model : ESXi 1 NIC1 113.11.11.11 from ISP NIC2 192.168.1.1 cross connect NIC2 ESXi2 VM CentOS6 ...