Questions tagged [disaster-recovery]
A set of policies and/or procedures that enable the recovery or continuation of vital infrastructure and systems. Please be sure to include what DBMS you are using.
189 questions
2 votes
1 answer
377 views
Do canary tables make sense for Availability Groups?
For all HA or DR solutions in SQL Server, I have heard that it is smart to have a table with a timestamp column in each database and to have an Agent Job run every minute to update that timestamp with ...
- 1,360
-1 votes
1 answer
4k views
The header for file 'xxx.mdf' is not a valid database file header. The FILE SIZE property is incorrect
Updated Question : The issue occurred when the SQL Data and Log Disk were unknowingly detached from the VM server. After realizing this, the disks were reattached, but the detachment and reattachment ...
- 25
1 vote
1 answer
166 views
Replay standby WAL to point in time without creating new timeline
We have a PostgreSQL 13 replication cluster where one of the standbys is setup with a recovery_min_apply_delay="x hr", which could be useful in the case of data corruption. For a scenario ...
- 700
1 vote
2 answers
61 views
Multi subnet failover for Azure PaaS failover groups
should the multisubnetfailover=True parameter be added to connection strings to Azure failover groups?
- 53
0 votes
0 answers
92 views
PostgreSQL: Is there any way to further optimise ASYNC replication towards less data loss during failover?
We are looking to see if there any further optimisations that can be done in PostgreSQL(13) ASYNC replication to make data loss near to zero as possible when a failover is triggered during disaster. ...
- 700
2 votes
1 answer
111 views
SQL Server Database I/O Consistency Error Disaster Recovery
I have a corrupted SQL Database that is inacessible by any means. It is to the point that simple commands, like USE MyDatabase, won't execute. The error I get is: SQL Server detected a logical ...
- 23
0 votes
1 answer
51 views
What is a viable low-cost DR option for a large cluster?
We have a Cassandra cluster running on GKE with a 32-CPU node pool and SSD disks. The current cluster size is nearly 1 PB, with each node utilizing an average of 5 TB on 10 TB allocated SSD disks. The ...
- 39
0 votes
0 answers
74 views
Always on availability group removing nodes
We have a SQL 2014 enterprise with 4 node availability group database with 2 Synchronous commit , 1 read only Asynchronous for reporting and 1 DR asynchronous. Due to space shortage we need to remove ...
- 1,117
0 votes
0 answers
55 views
Data Loss and data redeundancy when forced failed over to secondary replica on DR Data Center in SQL Server 2016
We are using SQL Server 2016 Enterprise edition and planning to have 2 datacenters primary and the remote Disaster recovery(DR). We have 2 replicas (primary replica and secondary replica) in the ...
0 votes
0 answers
74 views
Migrate cold database (freebsd) to mariaDb on ubuntu
I have a little bit of a pickle: I have a freebsd based jail that ran nextcloud with mysqldb The machine running the jail is broken. I still have the jail with the data. Now I was wondering if I can ...
- 1
0 votes
1 answer
220 views
Does application need to do anything to handle database failover?
I'm trying understand database failover (mainly in SQL Server) and what handling is required from application side to have zero downtime (no failures) to handle DB failover? Assuming that DBAs have ...
- 3
-1 votes
1 answer
48 views
Backup and Restore Disaster Recovery
I am using PowerShell to write a script for DR, assuming that we only have backup files of all the databases. If i have a latest sql server version and i want to restore some database from backup ...
-2 votes
2 answers
78 views
Does a DR plan need to be in place for an AlwaysOn availability group
I have two SQL servers 2022 in a normal availability group. I have heard that AG is capable of disaster recovery. Is this true or do I need to make an extra plan? Another question: Why is Failover ...
0 votes
1 answer
2k views
Mysqld won't start although lower_case_table_names is 0 and match the data dictionnary
I copied a mysql 8.0.26 database from a Linux server to my Windows box but mysqld won't start. Either it's this (with lower_case_table_names=1): [ERROR] [MY-011087] [Server] Different ...
- 111
2 votes
2 answers
15k views
SQL Server Connection String - MultiSubnetFailover True or Yes?
The MultiSubnetFailover option in database connection strings controls how the client attempts to connect to a database server, especially when multiple IPs are available. There is conflicting ...
- 1,955