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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Redundant serving of web application without loadbalancer?
I want to run a web application inside a mobile app using WebView. The web application uses IndexedDB for saving various important values. I like to make the web application very available (redundant)....
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FreeBSD ZFS raidz1 Started a (da59) drive replacement. During resilver, second drive (da60) failed
Our system started slowing down... Found a couple of drives in the same raid that looked scary.
Replaced the drive that S.M.A.R.T. marked as failure eminent. (da59)
Then da60 started to error.
Finally ...
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Can the Kubernetes master be geographically seperate from the nodes?
If I were to setup a kubernetes cluster, would it be possible and viable to have the kubernetes master in datacenter A, while having the nodes in datacenter B? I know there can be issues with having ...
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Plug single PSU into two different power sources
We have a rather uncommon situation:
We have a server in a computer center. Its got not enough spare space to put in a redundant PSU. Nevertheless, we want to attach the single PSU to both existing ...
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SSD Configuration choices for a 2-Way-Mirror Software RAID
I want data redundancy for my SSDs, and so would likely be using a software RAID like Windows Storage Spaces in a simple, fully-provisioned 2-way mirror configuration.
To minimize the risk of both ...
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How should the EFI System partition be made redundant without using hardware RAID?
What is BCP for making the EFI System partition redundant without using hardware RAID?
If I create 3x EFI System partitions on different devices and then backup any changes made to the primary (...
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AWS Multi Zone Redundancy - Load Balancer vs Global Accelerator vs Elastic IP what to use?
I am a bit confused with the Options for load balancing between different AZs for redundancy. I have an application which requires network load balancing and should optimally not depend on DNS to do ...
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How to configure samba+winbind with AD redundancy?
I work for a company that offers a software solution for network management. Part of the solution is proxy authentication. An already legacy option in our software, is to configure a proxy to use NTLM ...
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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 ...
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How to set up Parallel Redundancy Protocol on linux?
I'm trying to setup a PRP connection between to Linux machines (Ubuntu 20-04 LTS) following the doc from TI.
The module hsr is present (modprobe hsr works), but when I tried to use iproute2, it seems ...
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Finding network topology issues
I am trying to check a network with redundant links for possible issues with switching (STP?) and/or routing. I have a feeling that the issues are intermittent but I'm struggling to find a method how ...
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How do I (automatically) re-attempt to deliver mail from a different Postfix server?
My network consists of two different locations and in both I have a Postfix server running for outgoing mail on each of them. Mail gets submitted to any of the two round-robin, based on having them ...
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Is round-robin DNS a possible solution for high availability?
Let's say I have 2 IPs for a given domain (round-robin DNS).
If one the IPs becomes unresponsive, will clients try to connect to the other IP? or they will just fail to establish comunication with the ...
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Load balance the Load balancer
I am looking to get load balancing for my load balancer.
We are looking to create a fully HA network.
All of our servers are redundant, the databases are redundant, but above them is a single server ...
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hardware failover server configuration
need to achieve redundancy for offline local small business Document managing system server and need to know which configuration is better
considering zero down time and automated switching in failure ...
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How can i get a virtual machine in Hyper-V to carry on running in failover cluster. 2 Nodes, Server 2019
Forgive me if I am missing something obvious but I am very new to servers and failover clustering. I haven't found a question that quite answers what I am looking for yet.
My goal is to make a VM run ...
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Pacemaker/Corosync: how to emergency-shutdown all resources (VMs qemu/kvm)
Good morning everyone -
Running a 6 node Pacemaker/Corosync cluster with lots of productive qemu/kvm VMs on it, we were wondering how to best do an "emergency shutdown" of the whole lot, ie. ...
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Redundancy of Raid 10 with a hot spare?
Raid 10 has a 2N redundancy. What is the redundancy for Raid 10 with a hot spare?
Am I correct in thinking it is 2N+1 redundancy?
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Redundant network connections (using switches without link aggregation support)
I need to connect two Windows 10 PCs together via Ethernet. They will be connected in series through two managed switches (Microchip KSZ9897). Each PC has two Intel NICs.
I need the links to be ...
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1
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Newbie to Supermicro redundant PSU
Until recently I have never had a redundant PSU or a rack server for that matter. So, I think maybe I did this wrong? I have a Supermicro FatTwin 6026TT-HDTRF (CSE-827HD-R1400B case) that comes with a ...
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Using (dual) ATS for dual PSU server?
There's two parts to my question:
Does it make sense to hook up a dual PSU server to an ATS to speed up failover to the secondary circuit?
If yes, does it make sense to use two separate ATSes to ...
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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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VLAN - Network Redundancy With Same 2nd Switch?
Is it possible to set up the same VLANs on two different switches with same IPs, but different MACs on dual port network cards of servers? In case switch 1 is down or needs maintenance I would like ...
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Alternatives to Dell's mirrored SD card module for booting a small OS from flash?
Dell offers an add-on hardware card for some of their servers that provides a poor man's RAID1 between two SD cards (one card gets all the reads until it dies, writes are mirrored) for booting a ...
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"Dezentral" job management with redundancy/load balancing
I search a job management solution for local processes. Usually they run for some weeks.
At the moment I use a jenkins, but there the server is not restartable (security updates) and there is no ...
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How to set-up a secondary/redundancy LTE internet connection?
We're a small-medium office in Vancouver Canada, and we're looking to set-up a secondary/redundancy LTE internet connection. We're looking at purchasing the Unifi Dream Machine Pro to solve this issue,...
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Mirror Linux Systems Running Game Servers And Payment Managing servers
I am building a sort of professional hosting service and want to be able to just switch machines if something goes down on one I use AMP which is a web server along with a game hosting server platform ...
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stp - avoid links with packet loss
We have a set of devices connected in a ring, that are using stp (using https://github.com/mstpd/mstpd at the moment) to avoid issues with the loop. What we have seen, is that while stp can adapt the ...
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Is Round-Robin DNS "good enough" for load balancing static content?
We have a set of shared, static content that we serve up between our websites at http://sstatic.net. Unfortunately, this content is not currently load balanced at all -- it's served from a single ...
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Single isp dual failover links
I'm having a problem trying to configure my cisco 3945 router to use a dual hand-off wan links.
Lets say the ISP has provided the below ip addresses where they are doing hsrp at their end
ISP EDGE 1 ...
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Auto rebooting down servers
Currently have a web server VPS in Germany with Hetzner. They are offering free load balancer service. Thinking about cloning my VPS in their Finland site (meaning adding another VPS with cloned setup/...
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Best way to mirror a large drive onto two smaller ones
I have an 8.0 TB Drive which will soon start filling up with videos
I have two spare 4.0 TB Drives
The system is running Linux Mint 19 Tara and is my desktop system (Yes it's a big system able to ...
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DNS and failure tolerance strategies for load balancers
I'm trying to educate myself about how to build a highly available load balancing service for application servers for e.g. HTTP traffic and how they work with DNS servers.
Consider the following ...
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Single disk partial redundancy
I have a single external HDD that I'd like to use as storage for data that's not read/written very often. I'd like to make this storage resilient against faults that might occur.
ZFS apparently ...
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Redundant L2 Uplink (OS10)
I am trying to design a redundant uplink to a service provider from a pair of Dell S4112 switches running OS10. We a getting two uplink connections from the service provider, but they cannot be ...
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Postfix: Using sender dependent transport maps for redundancy and load balancing
I have a Postfix server and I'm trying to use two different IPs in two different connections / ISPs to send email.
The address 89.xxx.xxx.2 is the default system gateway at eth0 AND 188.xxx.xxx.2 is ...
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Redundancy for a device with 2 NICs on same subnet reaching other networks
I have a Linux based device with two NICs:
NIC1 eth0: 192.168.1.100/24; Gateway: 192.168.1.1
NIC2 eth1: 192.168.1.101/24; Gateway not set
This device communicates with an Application Server (IP: 10....
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How to be a redundant with VMs on this middle infrastructure?
I need to implement for an association three virtual machines to manage the domain and two other software that will use databases. Of course they don't have a big budget but I am trying with their ...
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1
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How does zfs raidz-2 recover from 3 drives down?
Im wondering what happened, how ZFS was able to recover completely, or if my data is still truly in tact.
When i came in last-night i saw this to my dismay, then confusion.
zpool status
pool: san
...
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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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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 ...
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Is ntp.ubuntu.com redundant?
Does anybody know if Ubuntu's NTP servers are redundant? If I dig them, I get:
;; ANSWER SECTION:
ntp.ubuntu.com. 280 IN A 91.189.94.4
vs. when I dig pool.ntp.org:
;; ANSWER SECTION:
pool....
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Local to Remote Webserver Failover
Short and sweet, I don't suppose you'll need more detail than this:
We host our website on an in-house
webserver.
A catastrophe has and will happen
again where communication from the
web into/out ...
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How to make redundant load balancers?
I understand that the purpose of load balancers is to balance load between your servers and keep track of instance health, etc. But what if load balancer itself fails? How do you set up redundant load ...
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Is there a way to add another redundant DNS along with CloudFlare?
My question stems from the recent incident with CloudFlare on July 2nd deploying bad software on their systems and causing downtime to most of their clients, including us. https://blog.cloudflare.com/...
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How to disable redundant path warning for a d2600 with 12 HP SATA drives?
Have a HP p822 RAID controller with FirmWare 8.32 cabled to a HPE d2600 with 12 x 4TB SATA drives in RAID60. These are not dual-port SAS drives, but 4TB SATA drives so there is only one pathway to ...
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Redundant Server Application [closed]
I have two identical servers, they run linux and they have a data base and a piece of software that is constantly recieving inputs. What is the right term that I should search for to be able to ...
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Do you lose everything when you have a hard disk failure in a multi-hard disk LVM that does NOT use RAID?
I'm debating about using LVM for a media/file server because I would like to combine multiple physical hard disks into one volume. I do not wish to use any RAID in my LVM so my question is:
If one ...
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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. ...
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Is there any value in protecting both rack power feeds with their own UPS?
I've done some looking and have not found a satisfactory answer to this question.
When is it necessary or suggested to use an independent UPS (on it's own mains branch circuit) for each power feed to ...