MISCONF Redis is configured to save RDB snapshots

Question

During writes to Redis   SET foo bar   I am getting the following error      MISCONF Redis is configured to save RDB snapshots  but is currently   not able to persist on disk  Commands that may modify the data set are   disabled  Please check Redis logs for details about the error    Basically I understand that the problem is that redis is not able to save data on the disk  but have no idea how to get rid of the problem   Also the following question has the same problem  it is abandoned long time ago with no answers and most probably no attempts to solve the problem

User · Accepted Answer

In case you encounter the error and some important data cannot be discarded on the running redis instance (problems with permissions for the rdb file or its directory incorrectly, or running out of disk space), you can always redirect the rdb file to be written somewhere else.

Using redis-cli, you can do something like this:

CONFIG SET dir /tmp/some/directory/other/than/var
CONFIG SET dbfilename temp.rdb

After this, you might want to execute a BGSAVE command to make sure that the data will be written to the rdb file. Make sure that when you execute INFO persistence, bgsave_in_progress is already 0 and rdb_last_bgsave_status is ok. After that, you can now start backing up the generated rdb file somewhere safe.

User · Answer

FWIW  I ran into this and the solution was to simply add a swapfile to the box  I used this method  https   www digitalocean com community tutorials how-to-add-swap-on-ubuntu-14-04

User · Answer

This error occurs because of BGSAVE being failed  During BGSAVE  Redis forks a child process to save the data on disk  Although exact reason for failure of BGSAVE can be checked from logs  usually at  var log redis redis-server log on linux machines  but a lot of the times BGAVE fails because the fork can t allocate memory  Many times the fork fails to allocate memory  although the machine has enough RAM available  because of a conflicting optimization by the OS  As can be read from Redis FAQ   Redis background saving schema relies on the copy-on-write semantic of fork in modern operating systems  Redis forks  creates a child process  that is an exact copy of the parent  The child process dumps the DB on disk and finally exits  In theory the child should use as much memory as the parent being a copy  but actually thanks to the copy-on-write semantic implemented by most modern operating systems the parent and child process will share the common memory pages  A page will be duplicated only when it changes in the child or in the parent  Since in theory all the pages may change while the child process is saving  Linux can t tell in advance how much memory the child will take  so if the overcommit memory setting is set to zero fork will fail unless there is as much free RAM as required to really duplicate all the parent memory pages  with the result that if you have a Redis dataset of 3 GB and just 2 GB of free memory it will fail  Setting overcommit memory to 1 says Linux to relax and perform the fork in a more optimistic allocation fashion  and this is indeed what you want for Redis   Redis doesn t need as much memory as the OS thinks it does to write to disk  so may pre-emptively fail the fork  To Resolve this  you can  Modify  etc sysctl conf and add  vm overcommit memory 1  Then restart sysctl with  On FreeBSD  sudo  etc rc d sysctl reload  On Linux  sudo sysctl -p  etc sysctl conf

User · Answer

you must chmod and chown the new folder   chown -R redis  and chmod

User · Answer

Start Redis Server in a directory where Redis has write permissions  The answers above will definitely solve your problem  but here s what s actually going on    The default location for storing the rdb dump file is     denoting current directory   You can verify this in your redis conf file  Therefore  the directory from where you start the redis server is where a dump rdb file will be created and updated    It seems you have started running the redis server in a directory where redis does not have the correct permissions to create the dump rdb file    To make matters worse  redis will also probably not allow you to shut down the server either until it is able to create the rdb file to ensure the proper saving of data    To solve this problem  you must go into the active redis client environment using redis-cli and update the dir key and set its value to your project folder or any folder where non-root has permissions to save  Then run BGSAVE to invoke the creation of the dump rdb file   CONFIG SET dir   hardcoded path to your project folder  BGSAVE    Now  if you need to save the dump rdb file in the directory that you started the server in  then you will need to change permissions for the directory so that redis can write to it  You can search stackoverflow for how to do that    You should now be able to shut down the redis server  Note that we hardcoded the path  Hardcoding is rarely a good practice and I highly recommend starting the redis server from your project directory and changing the dir key back to       CONFIG SET dir      BGSAVE   That way when you need redis for another project  the dump file will be created in your current project s directory and not in the hardcoded path s project directory

User · Answer

in case you are working on a linux machine  also recheck the file and folder permissions of the database  The db and the path to it can be obtained via  in redis-cli   CONFIG GET dir CONFIG GET dbfilename  and in the commandline ls -l  The permissions for the directory should be 755  and those for the file should be 644  Also  normally redis-server executes as the user redis  therefore its also nice to give the user redis the ownership of the folder by executing sudo chown -R redis redis  path to rdb folder  This has been elaborated in the answer here

User · Answer

On redis conf line  235 let s try to change config like this - stop-writes-on-bgsave-error yes   stop-writes-on-bgsave-error no

User · Answer

Had encountered this error and was able to figure out from log that the error is because of the disk space not being enough  All the data that was inserted in my case was not needed any longer  So I tried to FLUSHALL  Since redis-rdb-bgsave process was running  it was not allowing to FLUSH the data also  I followed below steps and was able to continue    Login to redis client Execute config set stop-writes-on-bgsave-error no Execute FLUSHALL  Data stored was not needed  Execute config set stop-writes-on-bgsave-error yes   The process redis-rdb-bgsave was no longer running after the above steps

User · Answer

I know this thread is slightly older  but here s what worked for me when I got this error earlier  knowing I was nowhere near memory limit- both answers were found above  Hopefully this could help someone in the future if they need it   Checked CHMOD on dir folder    found somehow the symbolic notation was different  CHMOD dir folder to 755 dbfilename permissions were good  no changes needed Restarted redis-server  Should ve done this first  but ah well  Referenced the redis-server log and found that the error was the result of access being denied   Again- unsure how the permissions on the DIR folder got changed  but I m assuming CHMOD back to 755 and restarting redis-server took care of it as I was able to ping redis server afterwards  Also- to note  redis did have ownership of the dbfilename and DIR folder

User · Answer

There might be errors during the bgsave process due to low memory   Try this  from redis background save FAQ   echo  vm overcommit memory   1   gt  gt   etc sysctl conf sysctl vm overcommit memory 1

User · Answer

I faced the similar issue  the main reason behind this was the memory RAM  consumption by redis  My EC2 machine had 8GB RAM arounf 7 4 available for consumption   When my program was running the RAM usage went upto 7 2 GB leaving hardly  100MB in RAM   this generally triggers the MISCONF Redis error      You can determine the RAM consumption using the htop command  Look for the Mem attribute after running htop command  If it shows high consumtion  like in my case it was 7 2GB 7 4GB  It s better to upgrade the instance s with larger Memory  In this scenario using config set stop-writes-on-bgsave-error no will be a disaster for the server and may result in disrupting other services running on the server if any   So  it better to avoid the config command and UPGRADE YOUR REDIS MACHINE   FYI  You may need to install htop to make this work   sudo apt-get install htop  One more solution to this can be some other RAM heavy service running on your system  check for other service running on your server machine instance and stop it if its not necessary  To check all the services running on your machine use service --status-all  And a suggestion for people directly pasting the config command   please do reasearch a bit and atleast warn the user before using such commands  And as  Rodrigo mentioned in his comment    It does not look cool to ignore the errors    ---UPDATE---  YOu can also configure maxmemory and maxmemory-policy to define the behavior of Redis when a specific limit of memory is reached  For example  if I want to keep the memory limit of 6GB and delete the least recently used keys from the DB to make sure that redis mem usage do not exceed 6GB  then we can set these two parameters  in redis conf or CONFIG SET command    maxmemory 6gb maxmemory-policy allkeys-lru   There are a lot of other values which you can set for these two parameters you can read about this from here  https   redis io topics lru-cache

User · Answer

Check your Redis log before taking any action  Some of the solutions in this thread may erase your Redis data  so be careful about what you are doing   In my case  the machine was running out of RAM  This also can happen when there is no more free disk space on the host

User · Answer

on redis 6 0 4    if show error  MISCONF Redis is configured to save RDB snapshots    Because redis doesn t have permissions to create dump rdb file sudo redis bin redis-server  sudo redis bin redis-cli

User · Answer

If you re running MacOS and have recently upgraded to Catalina  you may need to run brew services restart redis as suggested in this issue

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In my case it happened because I just installed redis using the quick way  So redis is not running as root  I was able to solve this problem by following the instructions under the Installing Redis more properly section of their Quick Start Guide  After doing so  the problem was solved and redis is now running as root  Check it out

User · Answer

A more permanent fix might be to look in  etc redis redis conf around lines 200-250 there are settings for the rdb features  that were not a part of redis back in the 2 x days   notably  dir      can be changed to  dir  home someuser redislogfiledirectory   or you could comment out all the save lines  and not worry about persistence   See the comments in  etc redis redis conf   Also  don t forget  service redis-server stop service redis-server start

User · Answer

Please  be aware  that this error appears when your server is under attack  Just found that redis fails to write to   etc cron d web  where after correcting of permissions  new file consisting of mining algorithm with some hiding options was added

User · Answer

In my case  the reason was very low free space in disk  only 35 Mb   I did the following -   Stopped all Redis related processe Delete some files in disk to make adequate free space Delete redis dump file  if existing data not needed   sudo rm  var lib redis   Delete all the keys of all the existing databases  sudo redis-cli flushall restart all celery tasks and check the corresponding logs for any issues

User · Answer

As pointed out by  Chris the problem is likely to to  low memory  We started experiencing it when we allocated too much RAM to MySQL  innodb buffer pool size    To ensure there s enough RAM for Redis and other services we reduced innodb buffer pool size on MySQL

User · Answer

Nowadays the Redis write-access problems that give this error message to the client re-emerged in the official redis docker containers    Redis from the official redis image tries to write the  rdb file in the containers  data folder  which is rather unfortunate  as it is a root-owned folder and it is a non-persistent location too  data written there will disappear if your  container pod crashes    So after an hour of inactivity  if you have run your redis container as a non-root user  e g  docker run -u 1007 rather than default docker run -u 0   you will get a nicely detailed error msg in your server log  see docker logs redis    1 M 29 Jun 2019 21 11 22 014   1 changes in 3600 seconds  Saving    1 M 29 Jun 2019 21 11 22 015   Background saving started by pid 499 499 C 29 Jun 2019 21 11 22 015   Failed opening the RDB file dump rdb  in server root dir  data  for saving  Permission denied 1 M 29 Jun 2019 21 11 22 115   Background saving error   So what you need to do is to map container s  data folder to an external location  where the non-root user  here  1007  has write access  such as  tmp on the host machine   e g   docker run --rm -d --name redis -p 6379 6379 -u 1007 -v  tmp  data redis   So it is a misconfiguration of the official docker image  which should write to  tmp not  data  that produces this  time bomb  that you will most likely encounter only in production    overnight over some particularly quiet holiday weekend

User · Answer

If you are running Redis locally on a windows machine  try to  run as administrator  and see if it works  With me  the problem was that Redis was located in the  Program Files  folder  which restricts permissions by default  As it should   However  do not automatically run Redis as an administrator You don t want to grant it more rights that it is supposed to have  You want to solve this by the book   So  we have been able to quickly identify the problem by running it as an administrator  but this is not the cure  A likely scenario is that you have put Redis in a folder that doesn t have write rights and as a consequence the DB file is stored in that same location   You can solve this by opening the redis windows conf and to search for the following configuration         The working directory              The DB will be written inside this directory  with the filename specified       above using the  dbfilename  configuration directive              The Append Only File will also be created inside this directory              Note that you must specify a directory here  not a file name      dir      Change dir    to a path you have regular read write permissions for  You could also just move the Redis folder in it s entirety to a folder you know has the right permissions

User · Answer

In case you are using docker docker-compose and want to prevent redis from writing to file  you can create a redis config and mount into a container  docker compose override yml    redis          volumes            -   redis conf  usr local etc redis redis conf         ports            - 6379 6379      You can download the default config from here  in the redis conf file make sure you comment out these 3 lines  save 900 1 save 300 10 save 60 10000   myou can view more solutions for removing the persistent data here

User · Answer

I hit this problem while working on a server with AFS disk space because my authentication token had expired  which yielded Permission Denied responses when the redis-server tried to save  I solved this by refreshing my token    kinit USERNAME HERE -l 30d  amp  amp  aklog

User · Answer

In my case it was related to disk free space   you can check it with df -h bash command  when I free some space this error disappeared

User · Answer

Thanks everyone for checking the problem  apparently the error was produced during bgsave   For me  typing config set stop-writes-on-bgsave-error no in a shell and restarting Redis solved the problem

User · Answer

After banging my head through so many SO questions finally -  for me  Axel Advento  s answer worked but with few extra steps   -  I was still facing the permission issues  I had to switch user to redis  create a new dir in it s home dir and then set it as redis s dir   sudo su - redis -s  bin bash mkdir redis dir redis-cli CONFIG SET dir   realpath redis dir  exit   to logout from redis user  optional

User · Answer

Restart your redis server     macOS  brew   brew services restart redis  Linux  sudo service redis restart   sudo systemctl restart redis Windows  Windows   R -  Type services msc  Enter -  Search for Redis then click on restart     I personally had this issue after upgrading redis with Brew  brew upgrade    After rebooting the laptop  it immediately worked

User · Answer

Using redis-cli  you can stop it trying to save the snapshot   config set stop-writes-on-bgsave-error no   This is a quick workaround  but if you care about the data you are using it for  you should check to make sure why bgsave failed in first place

User · Answer

I too was facing the same issue  Both the answers  the most upvoted one and the accepted one  just give a temporary fix for the same    Moreover  the config set stop-writes-on-bgsave-error no is a horrible way to over look this error  since what this option does is stop redis from notifying that writes have been stopped and to move on without writing the data in a snapshot  This is simply ignoring this error  Refer this  As for setting dir in config in redis-cli  once you restart the redis service  this shall get cleared too and the same error shall pop up again  The default value of dir in redis conf is      and if you start redis as root user  then    is   to which write permissions aren t granted  and hence the error   The best way is to set the dir parameter in redis conf file and set proper permissions to that directory  Most of the debian distributions shall have it in  etc redis redis conf

User · Answer

For me it was just a problem of permissions on the persistent redis data folder  I gave it a   chmod 777 -Rf data    And it s works    May be it s early to say it s resolve the issue  Because I also suspect that redis is not executing as root so I need to inspect my dockerFile to figure out more

User · Answer

all of those answers do not explain the reason why the rdb save failed   as my case  I checked the redis log and found   14975 M 18 Jun 13 23 07 354   Background saving terminated by signal 9  run the following command in terminal  sudo egrep -i -r  killed process   var log   it display    var log kern log 1 Jun 18 13 23 07 10-10-88-16 kernel   28152358 208108  Killed process 28416  redis-server  total-vm 7660204kB  anon-rss 2285492kB  file-rss 0kB  that is it  this process redis save rdb  is killed by OOM killer refers  https   github com antirez redis issues 1886 Finding which process was killed by Linux OOM killer

User · Answer

for me   config set stop-writes-on-bgsave-error no   and I reload my mac  it works

[redis] MISCONF Redis is configured to save RDB snapshots

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