Replication is the process of sharing information so as to ensure consistency between redundant resources, such as software or hardware components, to improve reliability, fault-tolerance, or accessibility.

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41
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10answers
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PostgreSQL Replication

We constantly bat this around the office, and the question continues to come up. How do you deal with PostgreSQL replication? I'm not even necessarily talking about advanced clusters, just keeping it ...
16
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4answers
499 views

Starting a branch office on the other side of the world

Going to cut right to the point on this question, as I'm after as diverse range of solutions as possible so don't want to effect any opinions with the question too much. Client is a UK based ...
15
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2answers
17k views

Reload my.cnf without restarting MySql service

I have to configure a Mysql server to act as a replication-master. I modified my.cnf to activate binary logs, but now in order to reload configuration I have to reload the service with ...
13
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3answers
4k views

MySQL Replication Performance

I'm having a serious issue with MySQL 5.5 replication performance between two machines, mostly myISAM tables with statement based replication. The binary logs and mysql data directory are both located ...
12
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3answers
3k views

How fast is MySQL replication?

I'm considering setting up replication of our mysql db to be able to have local slaves in each of our branch offices, while having the master in the main office to improve application performance ...
12
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7answers
10k views

USABLE multi-master replication for Postgres?

I tried Postgres-XC and it doesn't implement full SQL yet (like SERIAL) Postgres-R looks interesting but it's "not production ready" according to developers. So I used pgpool-II 3.0.1. Yes, it ...
11
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4answers
2k views

Windows Domain replication monitoring tool

I am looking for web-based interface GUI, or some kind of monitoring tool that will show replication status for a domain. I know I can use repadmin with various options on the command line to query ...
11
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4answers
1k views

Has anyone ever used SMTP site links?

A simple real-life question, inspired by a comment here: Active Directory has supported inter-site replication using SMTP instead of direct RPC since its first introduction in Windows 2000. But did ...
10
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2answers
1k views

Expected performance of e-SATA port multiplication?

For a certain read/write workload, I get 30 MiB/s from a 4-disk array using esata port multiplication. When I move the exact same array to four individual sata connections, I get 90 MiB/s for the same ...
8
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4answers
5k views

Is DRBD the only viable block replication solution for Linux?

I've found myself needing redundant storage at a block level. File-level replication (Gluster, GFS, etc) does not work for my use case. It looks like DRBD is the go-to solution for block ...
8
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2answers
5k views

Windows DFSR - Changed replicated directory permissions and now have a 350,000 backlog for more than a week

Question: Is there a way to make this 350,000 file backlog complete faster? For nearly every file the only change was a change to the ACL for each affected file. Some files have changed content, ...
8
votes
1answer
392 views

Why would a domain controller encouter a USN rollback after an unclean shutdown?

I have this Windows Server 2008 R2 domain controller running on a physical Dell server, model PowerEdge R510. There are some electrical problems around here, thus a black-out is, unfortunately, quite ...
8
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2answers
1k views

Is it safe to replicate from Solaris ZFS to FreeBSD ZFS?

Is it safe to replicate from a Solaris 10 ZFS v22 to a FreeBSD 8.3 ZFS v28? Are there someone that have done this with specific versions of ZFS, where it worked perfectly?
7
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2answers
523 views

How can I save a domain controller after a USN rollback without rebuilding the whole server?

Today I had (again...) to lobotomize a domain controller which had suffered the dreaded USN rollback; the standard solution to this issue is to demote it and then promote it back again, but the main ...
7
votes
1answer
353 views

one of the single dc per domain DCs has suffered USN rollback

I've inherited an Active Directory forest that is laid out very badly. It has a single forest with a domain tree for each site, each with a single domain controller. No domain is a child of any ...
7
votes
1answer
579 views

ZFS replication between 2 ZFS file systems

I initially replicated tank/storage1 --> usb1/storage1-slave (depicted below), and then (deliberately) destroyed the snapshot I replicated from. By doing this, did I lose the ability to incrementally ...
7
votes
5answers
3k views

Block-level LUN replication options for Windows [closed]

When it comes to replicating a LUN or partition to a physically separate server, Linux has DRBD (now in the kernel!). As I understand it, it has both synchronous and asynchronous replication modes. ...
6
votes
2answers
932 views

What does zfs receive -F do?

When I read man zfs for zfs receive I see -F Force a rollback of the file system to the most recent snap- shot before performing the receive operation. If receiving an ...
6
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9answers
7k views

Make identical copy of Centos

I have a CENTOS server running and i want to make identical copy of it(all software,users), like twin server for mirroring purposes. how do i do that?
6
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3answers
959 views

What are the typical methods used to scale up/out email storage servers?

What I've tried: I have two email storage architectures. Old and new. Old: courier-imapds on several (18+) 1TB-storage servers. If one of them show signs of running out of disk space, we migrate ...
6
votes
4answers
1k views

Prevent non-replication writes to MySQL slave?

We have some MySQL database servers set up with row-based replication, for performance. The software writes to the master, and reads from either the master or the slave. Everything's working great, ...
6
votes
6answers
4k views

Is it possible to use an EC2 RDS MySQL instance as a slave to an external master?

I have a master MySQL instance running on our local network, but I was wondering if I can get an EC2 RDS instance to replicate the master or is this locked down by amazon?
6
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3answers
2k views

Replicate a big, dense Windows volume over a WAN — too big for DFS-R

I've got a server with a LOT of small files -- many millions files, and over 1.5 TB of data. I need a decent backup strategy. Any filesystem-based backup takes too long -- just enumerating which ...
6
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6answers
3k views

Syncing multiple wordpress web servers in a farm

My company will shortly be setting up a blog, and I'm planning on setting up two web servers to host the wordpress website for redundancy. Normally when we do releases to a site in a farm we push to ...
6
votes
2answers
2k views

MySQL replication issues after a power outage

After a power outage at our data centre, the slave MySQL databases are struggling. This is in the logs for one of the slaves: 100118 10:05:56 [Note] Slave I/O thread: connected to master ...
6
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2answers
2k views

Scalable CouchDB setup

I want to migrate an existing application that has approx. 10 million records stored in a relational database to CouchDB. The thing that I love about CouchDB is easy replication and fast cached views. ...
6
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4answers
857 views

Is GlusterFS a good pick for keeping webservers in sync?

I've got 2 webservers, with the chance of having to add more servers along the way. Right now I keep these servers in synch using lsyncd + csync2. It works well performance wise because all files are ...
6
votes
1answer
323 views

Replacement for MySQL proxy

We have a standard MySQL Master/Slave replication for our database. In order to use the slave server we have set up MySQL Proxy. However we have been strongly discouraged to use it as it still alpha ...
6
votes
2answers
364 views

Data from a table in 1 DB needed for filter in different DB

I have a Win Form, Data Entry, application that uses 4 seperate Data Bases. This is an occasionally connected app that uses Merge Replication (SQL 2005) to stay in Sync. This is working just fine. ...
6
votes
1answer
387 views

DFSr detected that a file was changed on multiple servers, but “winning” file and that moved to conflicts folder have same hash

We've just deployed a new DFS replication system between two Windows 2012 R2 servers. We cloned the DFSr database using MS's recommendations ...
5
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6answers
2k views

Making Active Directory changes atomic

I've got a Windows 2003 Active Directory infrastructure, and there are times (such as when terminating an employee) that I want instantaneous propagation across both of my AD servers. Currently, I ...
5
votes
2answers
823 views

How to scale out OpenStreetMap data efficiently

For over a year now, I'm running an in-house PostGIS server filled with OSM data, used for both Mapnik-based tile generation and Nominatim-based geocoding, updated with day replicates. This works ...
5
votes
3answers
3k views

Create a MySQL slave from another slave, but point it at the master

Problem I have MySQL replication setup between 2 servers, master (A) and slave (B). I need to add a new slave to the mix (C). I want this slave to get it's updates directly from the master, I do not ...
5
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4answers
927 views

Testing MySQL Database Replication / Synchronization

I'm setting up a MySQL Master database which replicates to a few Slave databases. My question is what are the best practices to monitor and / or test that the slave databases are up-to-date, and that ...
5
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5answers
3k views

How can I rebuilt MySQL replication without dumping the master?

Our MySQL database has grown fairly large, and I am running with master replication. Replication is broken. I am trying to rebuild the second master without freezing up the first master in doing a ...
5
votes
2answers
3k views

Way to avoid server downtime when creating Master - Slave relationship?

I am preparing for setting up a MySQL master-slave or master-master relationship. Right now I have a single MySQL production server, and of course I don't want a lot of downtime while I connect the ...
5
votes
1answer
15k views

How to monitor DFSR backlog more efficiently than dfsrdiag

Is there a way to monitor the DFSR backlog in a manner more efficient than using dfsrdiag.exe backlog? I wrote a program that just slurps in the backlog count via dfsrdiag.exe backlog /smem:alpha ...
5
votes
2answers
290 views

Can you sync two different domains on MS DNS server?

Lets say you are running a domain X, but want your internal DNS server to handle requests for both domain X and domain Y such that if machine1.X resolves to a.b.c.d, that machine1.Y would resolve to ...
5
votes
2answers
15k views

Why is GPO Tool reporting a GPO version mismatch when the GPO version #'s do match?

Any ideas why the group policy diagnostic utility GPOTool would report a GPO version mismatch between two domain controllers if the version numbers are a match? Policy {GUID} Error: Version mismatch ...
5
votes
1answer
588 views

Replication of lockoutTime attribute is not urgent on AD-LDS

I have two LDS servers on the same subnet. They replicate well. If I change an attribute, it gets replicated after 15 seconds. LDS is configured to honor password policies. When a user makes too ...
5
votes
2answers
3k views

KVM Hosting: How to efficiently replicate guests

I have three KVM servers each with 1 guest VM, running directly on it's local storage, (so they are essentially getting a dedicated box worth of computing power each). In the event of a host failure I ...
5
votes
2answers
413 views

Mysql master-master not replicating

I'm setting up a master-master mysql replication on two servers (db1 and db2). I started with setting up db2 as a slave to db1 and that works fine. But when I set up db1 as a slave to db2 it isn't ...
5
votes
1answer
2k views

PostgreSQL 9: Does Vacuuming a table on the primary replicate on the mirror?

Running PostgreSQL 9.0.1, with streaming replication keeping one read-only mirror instance up to date. Auto-vaccuum is on on the primary, except for a few tables which are not vacuumed by the ...
5
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1answer
1k views

why use mixed-based replication for mysql

I am in the process of configuring MySQL replication and am intending to use row-based-replication but I was also reading up about mixed-based replication. This is where statement-based is the ...
5
votes
0answers
379 views

Is it a good idea to store Docker volumes in glusterfs?

I am currently thinking about migrating some of our servers and apps to a coreos enviroment. One of the problems I see here is the management of persistent data as coreos does not handle Docker ...
4
votes
2answers
212 views

Is there a safe way to bypass a non-replicating DC?

We have a domain controller that was virtualized a while back; this caused issues with replication that we're now seeing fallout from. I've moved the PDC Emulator and other fsmo roles to a new DC and ...
4
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18answers
5k views

How to Eliminate Tape Backup and Off-site Storage Service?

PLEASE READ UPDATE AT THE BOTTOM. THANKS! ;) Environment Info (all Windows): 2 sites 30 servers site #1 (3TB of backup data) 5 servers site #2 (1TB of backup data) MPLS backbone tunnel connecting ...
4
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6answers
4k views

Need help with estimating required bandwidth for SAN array to SAN array replication over WAN

I have a long-term goal of setting up a DR site in a colo somewhere and part of that plan includes replicating some volumes of my EqualLogic SAN. I'm having a bit of a difficult time doing this ...
4
votes
5answers
5k views

mirrored filesystem across a few servers

I'm looking for a solution to mirror or replicate one directory (or one filesystem) across a few Linux servers. Ideal solution would be one, which permits all servers read-write access. I also want it ...
4
votes
3answers
98 views

Replicating a linux web server

I'm planning on replicating a web server for high availability purposes. The server is running as a Ubuntu 15.04 virtual machine in Hyper-V and has MariaDB 10.0, Apache 2.4 and PHP-FPM 5.6 installed. ...