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Questions tagged [redundancy]

Redundancy is the duplication of critical components or functions of a system with the intention of increasing reliability of the system, usually in the case of a backup or fail-safe.

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High Available service - IP/DNS single point of failure

I'm looking for High Available solution for websites and already find Kubernates , Docker Swarm ... but all these things should balance only webserver , db and other running service in the cluster. ...
0
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0answers
10 views

Proxmox HE shared storage redundancy

I am currently reading myself into Proxmox HE clusters. They mention everywhere how important it is to have redundant components (NICs, switches, etc.) but it is never mentioned that the ISCSI target ...
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0answers
76 views

Failover Nginx reverse proxy

I am looking to setup my Nginx reverse proxy to handle a server failure or Nginx failing for some reason or another. I know how to configure nginx to work as a load balancer/ reverse proxy for other ...
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1answer
83 views

Network bonding active-backup mode with two switches

This below is a sample of my network. I have two interfaces on one machine eth0: 192.168.150.2 and eth1: 192.168.150.3 and I want make my network redundant using mode=1 which is active-backup, so if ...
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0answers
201 views

Multiple IpSec VPNs in failover config - pfSense to Draytek

I am looking to create redundant IpSec VPN Tunnels between two sites. I already have one VPN operational but due to overlapping LAN IP ranges I cannot have more VPNs active at the same time for ...
0
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2answers
265 views

Two DHCP servers giving static addresses in a network

I have a network having two servers that are occasionally booted. I wish to maintain DHCP services even during a boot of one server. One of the servers currently has a DHCP server that gives static ...
0
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1answer
52 views

Does it make sense to connect a redundant power supply to a C14 splitter?

Recently visiting a small data room, I noticed that redundant power supplies of a server are connected through a C14 splitter which, in turn, is connected to a single socket of a UPS. I told the ...
0
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1answer
19 views

Implementing an automated mail backup/forwarding service?

I have a senario in mind but I'm not sure how it should be implemented: I have a mail service with an mx record and an IP address. This mail server could be down sometimes. The incoming mails to this ...
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0answers
254 views

How to have multiple routes to the same remote VPN in pfSense?

We have a pfSense server in two offices. Our main office has a VPN server configured, and our satellite office has a VPN client configured, using the IP 123.156.88.253 (just an example). We have just ...
0
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1answer
109 views

ESXI NIC Teaming Policy x 2 physical swith x Shaper\BGP router

I have a BPG/Shaper with 2 interfaces configured in Bond0 (Loadbalance-RoundRobin)then connect one to each switch (one in Red one in Blue). ESXI is the same thing, 2 interfaces in one vSwitch NIC ...
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2answers
95 views

Best approach to achieve high availability and disaster recovery?

We are deploying SQL servers at two geographically distant sites. The bandwidth between two sites is 10Mbps. The requirement is to have both sites writable/readable. Both sites have redundancy ...
0
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1answer
53 views

Is it logical and safe to add Nginx cache expiration directive to the default conf?

This is my Nginx default conf (sites-available/default), which I use as base conf for all apps: server { # listen, root, index, server_name, locations; listen 80 default_server; listen [::...
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4answers
48 views

enabling Spanning-Tree or not

do you think is wise or stupid keeping the rapid spanning tree enabled for just two switches in this image? https://imgur.com/a/XI1NI As you can see the switches are not redundant each other but are ...
6
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3answers
1k views

is ceph possible to handle hardware RAID arrays (LUNs) as OSD drives?

I am pretty new to ceph and try to find out if ceph supports hardware level raid HBAs. Sadly could not find any information. What I found is, that it is recommended to use plain disks for OSD. But ...
2
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1answer
282 views

Upstream Nginx location blocks into site confs

I have a few websites on a Ubuntu 16.04-Nginx server environment and the Nginx conf file of each includes this set of location blocks: location ~* \.(jpg|jpeg|png|gif|ico|css|js|ttf|woff|pdf)$ { ...
2
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1answer
103 views

Which distributed filesystem will actually fit my needs?

Hear me out I have seen the question asked (in different forms) here, here, and perhaps the best one I found was here, but I do not think this is a duplicate because quite some time has past since ...
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2answers
77 views

DNS hosting design - should secondary server not be spread over countries, networks etc? [duplicate]

My DNS registrar and DNS provider recently had a long outage, rendering all my domains unusable (email, own+client websites etc). They have 3 DNS server, who are all in the same co-hosting facility! ...
1
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2answers
45 views

Can't access ZFS formatted drives (redundant setup)

I keep my important data on 2 drives that are mirrored (I think that is the correct terminology) in a machine running Ubuntu 12.04 LTS. Today, I was unable to access any of the data and 'sudo zpool ...
6
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4answers
3k views

If a RAID controller fails, does it disrupt service until it's replaced?

If I have 2 drives in a RAID 1, and the Raid Controller fails, does that mean the websites on the server will have downtime until the controller is replaced? Or does everything still carry on as ...
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1answer
87 views

How many drives can fail in an Xserve RAID in RAID 0+1? [closed]

I’m torn between what I know (or think I do) and what Apple’s documentation states. The hypothetical setup I’m considering is what is described as RAID 0+1 in Apple’s documentation for the Xserve ...
0
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0answers
34 views

How do region based services with a single backing database work to improve redundancy or load balancing?

I've used services where there are multiple application servers spread out throughout US, at least I have to assume because I could explicitly use urls like EastUS.email.Com or WestUS.email.Com or ...
0
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2answers
23 views

Is it possible to boot from a DAS device with read-only access?

Without boring you with the details, I'd like to run two servers from the same DAS. One server would be the primary server and would have read / write access to the DAS. The other server will be the ...
2
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2answers
648 views

How to manage redundant ISPs with dynamic DNS

I'm trying to make my small business network a bit more robust by adding a fallback ISP. What I can't figure out is how to manage the DNS for inbound connections. A simplified view of my network looks ...
3
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1answer
162 views

Openstack redundant architecture on three servers

I would like to deploy an Openstack architecture on three (super)servers in a way that if one of server is down the Openstack infrastructure is still functionning. What is the best way to deploy ...
9
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2answers
160 views

Redundant Power Supply Sloshing (If sloshing is the right word)

I have a Supermicro Redundant Power Supply with two units in it. I also have two UPS units, one for each of the Power Supplys. I was watching the LCD on the UPSs for the watt usage. The total watts ...
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2answers
211 views

Methodology to find a “stable” IP addres within some ISP's AS network

Some definition(s)/meaning(s): Stable IP address - a host within Internet Service Provider (ISP) Autonomous system (AS) network, replaying to ICMP type 8 echo request. Genesis: My routers monitor ...
0
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1answer
80 views

Connect switches using SFP connectors or uplink

In our environment we have 2 server rooms. One is our primary server room where internet is comming in and where our main servers are located. Then we have a secundary server room where our backup ...
0
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0answers
47 views

Webserver backup on VPS

I have my own server with webhosting with 80+- webpages(php + apache) + mail. I want make some backup/redundancy when my primary server go offline (bad internet or electricity) on VPS. It is possible ...
8
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3answers
347 views

Increase reliability by partitioning disks of different size?

I understand ZFS would prefer all disks carrying the same size. However, in the case that I have two disks with different size (1TB and 1.5TB), I'd like to have certain redundancy, but not mirroring. ...
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3answers
602 views

Is it possible to have multiple storage servers in a failover cluster?

I'm familiar with setting up RAID arrays and am running a few in my home environment. I was wondering if it's possible to have multiple storage servers in a failover configuration. What I hope to ...
1
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5answers
153 views

Server Network Redundancy and Availability

If I have one server with RAID 50 or 10, then data is distributed among hard drives in case one fails. Can the same be done across multiple servers. Can data be distributed among multiple servers, so ...
0
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1answer
144 views

Best approach for redundant storage DAS/SAN

We've always used DAS storage (which as per Dell standards) have multiple controllers for redundancy, multiple PSUs etc. However, in the event of full hardware failure (which may or may not be likely) ...
0
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1answer
612 views

OpenStack Redundant Ceph/Cinder Storage Architecture

Hello Serverfault community, I'm currently designing an OpenStack cluster. The part where I'm currently stuck is the Storage Architecture. I thought of building two redundant Ceph clusters in ...
1
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1answer
285 views

How to safely store data and DBs on Kubernetes (or similar) on DigitalOcean

It boils down to setting up a private cloud on something like Digital Oceans versus another hosting solution like GCE or AWS. The latter have redundant data stores that can be safely used as volumes, ...
0
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0answers
158 views

Best Reliability for Linux OS: FakeRAID, SoftRAID, or No RAID

I'm tasked with building a highly-reliable, unmanned industrial PC that will withstand unplanned power outages. A UPS will be used where possible, but realistically we know that many of these units ...
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1answer
73 views

Backup DNS servers for a domain name - optimal configuration and troublehooting

Let's say we have these name servers for 1 domain. ns.1.com ns.2.com ns.3.com ns.4.com backup-ns.1.com backup-ns.2.com How can I know which NS responded to this specific query, for example using dig?...
12
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2answers
2k views

Is it possible to have a secondary managed DNS provider to quickly delegate to when DDOS attack on our *primary* external DNS provider happens?

So our DNS provider, every so often, experiences DDOS attacks on their systems that causes our front-facing web sites to go down. What are some options in terms of reducing dependency on a SINGLE ...
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2answers
84 views

Fallback between datacenters

What is the best way to do a fallback between datacenters. We have a dedicated server in one of the data centers and as our traffic increased i wanted to add more then backup i wanted redundancy and ...
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1answer
103 views

Need some clarification on a NIC functionality on a Dell Poweredge r610

Quick question. I'm trying to understand the NIC functionality of this server. NIC specs from manual: My question is, do the two broadcom controller chips provide fail-over redundancy? For example, ...
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2answers
2k views

VM migration and IP address

When a VM offering a service is migrated to a different server is it an important requirement from the client applications point of view to retain the same IP the VM had before ? For long lived TCP ...
4
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1answer
532 views

How to setup redundant ejabberd servers?

I currently have an ejabberd server running at domain A. It has a bunch of users with accounts like xyz@A. I want to setup alternative servers so that if A is down, clients can transparently use ...
0
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1answer
39 views

Is it feasible to switch DNS A records to point to a backup provider in case of failure?

Is it feasible to switch DNS A records to point to a backup provider in case of failure? Instead of relying on one provider/datacenter. I know there is a lag due to ISPs caching the records, but it'...
5
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2answers
2k views

NTP: How to establish redundant solution for NTP servers?

In my company's infrastructure there are 5 data centers in remote locations. In each remote location, there's a pair of servers which hold DNS and NTP services and are configured on each one of the ...
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1answer
74 views

Distributed (serverless) Database System [closed]

I've currently a setup where 10 database clients access one (Postgres)-SQL server on the same network. The applications have a very low db footprint. They do load a few tables upon startup and do ...
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votes
2answers
58 views

Common Practice for router setup in a business [closed]

At the company that I'm working for, we have one router (SonicWall TZ 210) and it occasionally go down during business hours. All I have to do to bring it back up is to power cycle the router but ...
2
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1answer
372 views

Achieving File Server Redundancy

We are in the process of moving all servers (or virtualising physicals) into a central datacenter connected via MPLS. Currently we are fully redundant on most aspects - RDS Farms, SQL Clusters, ...
0
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2answers
298 views

Creating a redundant environment with ONLY 2 servers (so without a third server that handles the load-balancing) [duplicate]

First of all, i'm sorry if this question has been answered before, but i've been searching for a while now and couldn't seem to find (or understand) an answer. So, i have two physical servers with ...
3
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1answer
348 views

Can my redundant network setup be made more robust?

With my current design I have a DL380 Gen9 running ESXi. It has redundant NICs cabled to two different switches. Those switches in turn are both cabled to a third switch that allows my workstation to ...
1
vote
2answers
1k views

Host using Linux bond mode 1 (active/backup) connected to 2 x independent switches

I have a host using Linux bond mode 1 (active/backup) connected to 2 x independent switches. Please can someone confirm if this is possible for successful failover between NICS or do I have to ...
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2answers
416 views

What's the best method to achieve full redundancy in a dedicated server? [closed]

I've been reading about full redundancy to achieve almost if not 100% uptime for your mission critical applications (handling financial data) running in a dedicated server, but I still can't wrap my ...