I'm experiencing some weird behavior on the google compute engine. I made a new instance with ubuntu on it. I installed a node app I'm working on, pulled code from github etc...
then I installed mongodb and nginx. The weird thing is, every time I leave the session, and reconnect, my mongodb and nginx installation files disappear.
for example, when I install nginx I find the nginx installation on /etc/nginx where I can find like nginx.conf. but when I left the compute engine console session, and reconnected later, that directory was gone. same thing is happening with mongodb.
my node installation under /home/abdul/mystuff doesn't disappear though.
is this normal? is it a setting?
details:
this is an ubuntu image (idk which version, and not sure how to check)
using the following to install nginx:
sudo apt-get update
sudo apt-get install nginx
result of command
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 10G 0 disk
└─sda1 8:1 0 10G 0 part /var/lib/docker/aufs
sdb 8:16 0 5G 0 disk
└─sdb1 8:17 0 5G 0 part /home
Looks like you're running a Docker container on your instance (/var/lib/docker/aufs) and installing the software inside the container.
If you want to save changes back to the image, it is possible to use the docker commit command, but this is almost definitely not what you want.
Instead, use a Dockerfile to build images and update it whenever you want to make a change. This way you can easily recreate the image and make changes without starting from scratch. For persistence (.e.g. config files and databases) use volumes, which are just directories stored outside of the Union File System as normal directories on the host.
Related
I changed the mongod.conf.orig of the mongo running on ECS, but when I restart, the changes are gone.
Here's the details:
I have a mongodb running on ECS, it always crashes due to out of memory.
I have found the reason, I set the ECS memory to 8G, but because the mongo is running in a container, it detected a higher memory.
when I run db.hostInfo()
I got the memSizeMB higher than 16G.
It caused that when I run db.serverStatus().wiredTiger.cache
I got a "maximum bytes configured" higher than 8G
so I need to reduce the wiredTigerCacheSizeGB in config file.
I used the command line copilot svc exec -c /bin/sh -n mongo to connect to it.
Then I found a file named mongod.conf.orig.
I ran apt-get install vim to install vi and edit this file mongod.conf.orig.
But after I restart the mongo task, all my changes are gone. include the vi I just installed.
Did anyone meet the same problem? Any information will be appreciated.
ECS containers has ephemeral storage. In your case, you could create an EFS and mount it in a container, then share the configuration.
If you use CloudFormation, look at mount points.
I'm currently testing OS and version upgrades for a ceph cluster. Starting info:
The cluster is currently on Centos 7 and Ceph version Nautilus. I'm trying to change OS with ubuntu 20.04 and version with Octopus. I started with upgrading mon1 first. I will write down the things done in order.
First of I stopped monitor service - systemctl stop ceph-mon#mon1
Then I removed the monitor from cluster - ceph mon remove mon1
Then installed ubuntu 20.04 on mon1. Updated the system and configured ufw.
Installed ceph octopus packages.
Copied ceph.client.admin.keyring and ceph.conf to mon1 /etc/ceph/
Copied ceph.mon.keyring to mon1 to a temporary folder and changed ownership to ceph:ceph
Got the monmap ceph mon getmap -o ${MONMAP} - The thing is i did this after removing the monitor.
Created /var/lib/ceph/mon/ceph-mon1 folder and changed ownership to ceph:ceph
Created the filesystem for monitor - sudo -u ceph ceph-mon --mkfs -i mon1 --monmap /folder/monmap --keyring /folder/ceph.mon.keyring
After noticing I got the monmap after the monitors removal I added it manually - ceph mon add mon1 <ip> --fsid <fsid>
After starting manually and checking cluster state with ceph -s I can see mon1 is listed but is not in quorum. The monitor daemon runs fine on the said mon1 node. I noticed on logs that mon1 is stuck in "probe" state and on other monitor logs there is an output such as mon1 (rank 2) addr [v2:<ip>:3300/0,v1:<ip>:6789/0] is down (out of quorum) , as i said the the monitor daemon is running on mon1 without any visible errors just stuck in probe state.
I wondered if it was caused by os&version change so i first tried out configuring manager, mds and radosgw daemons by creating the respective folders in /var/lib/ceph/... and copying keyrings. All these services work fine, i was able to reach to my buckets, was able to open the Octopus version dashboard, and metadata server is listed as active in ceph -s. So evidently my problem is only with monitor configuration.
After doing some checking found this on red hat ceph documantation:
If the Ceph Monitor is in the probing state longer than expected, it
cannot find the other Ceph Monitors. This problem can be caused by
networking issues, or the Ceph Monitor can have an outdated Ceph
Monitor map (monmap) and be trying to reach the other Ceph Monitors on
incorrect IP addresses. Alternatively, if the monmap is up-to-date,
Ceph Monitor’s clock might not be synchronized.
There is no network error on the monitor, I can reach all the other machines in the cluster. The clocks are synchronized. If this problem is caused by the monmap situation how can I fix this?
Ok so as a result, directly from centos7-Nautilus to ubuntu20.04-Octopus is not possible for monitor services only, apparently the issue is about hostname resolution with different Operating systems. The rest of the services is fine. There is a longer way to do this without issue and is the correct solution. First change os from centos7 to ubuntu18.04 and install ceph-nautilus packages and add the machines to cluster (no issues at all). Then update&upgrade the system and apply "do-release-upgrade". Works like a charm. I think what eblock mentioned was this.
I run a centos 8 distro on docker and I would like to have bash TAB completion with dnf package manager. According to other posts, I did the following once my docker container is started:
dnf clean all && rm -r /var/cache/dnf && dnf upgrade -y && dnf update -y
and then
dnf install bash-completion sqlite -y
After doing that I restart the container but there is still no bash completion. I also tried to source directly the bash completion file by doing:
source /etc/profile.d/bash_completion.sh
but without any better effect.
Would you know what I am doing wrong ?
You shouldn't need BASH Completion in a Docker container. The only time you should be manually connecting to a shell inside a Linux container is to troubleshoot why the process running in the container is behaving abnormally. In fact, some container design advice might even go as far as suggesting you not include a shell inside your base OS at all!
The reason this isn't working for you is due to the way in which Linux containers operate. A Container is simply a namespaced process that is managed by the kernel installed on the Host OS. This process cannot be modified or interrupted or the container will be destroyed since the process will be sent a SIGTERM. When you attempt to source the bash_completion.sh script, you are attempting to pass new configuration arguments to your existing namespaced process managed by Docker.
If you really wanted to do this the best way to do it would be to create a new Docker Container Image based on the original CentOS 8 Base Image. And then from there install the bash completion package and add an echo command to add the source line to your user's .bashrc file.
EDIT:
With regards to the additional question asked OP in the comments of this answer I have added additional information below.
Why should not I need bash completion in a container
The reason you do not need bash completion in a container is because containers are not meant to be attached to with a shell. A is simply supposed to be a single instance of a process running under specific configured criteria. Containers aren't meant to be used to create dev environments for you to connect to, they're meant to run processes and applications in software infrastructure.
Manually updating & installing packages
You mention that one of the first things you do when you spin up a container is install packages. This is also alarming to me because you are not supposed to be manually interacting with a container at all. This includes package installation. Instead, you should generate a new Container Image from the older Base Image and add additional RUN statements to the Dockerfile to update the system and install these desired packages.
Cannot believe it is not possible
It is possible if you create a new Dockerfile that purposely installs it on a new layer of the base image and produces a new container image for you to use. BUT the point is that you shouldn't be connecting to Docker containers in the first place to even get to a point where you could need something like bash completion!
Here is a great summary on the difference between a container and a virtual machine that might help clarify some of this for you. In a nutshell, containers are supposed to run, and only run, processes.
I am using Ubuntu 16.04 server. I have a couple of apps that are running and therefore can't reboot occasionally. Because of this my /tmp folder is filling up pretty fast and sometimes I have problem with logging in to the server
I want help with redirecting /tmp to another path like /mnt so I will be able to clear it periodically.
I have a VM Instance with a small 10GB boot disk running CentOS 7 and would like to mount a larger 200GB Persistent Disk to contain data relating to the /home directory from a previous dedicated server (likely via scp).
Here's what I tried:
Attempt #1, Symlinks Might work, but some questions.
mounted the disk to /mnt/disks/my-persistent-disk
created folders on the persistent disk that mirror the folders in the old server's /home directory.
created a symlink in the /home directory for each folder, pointing to the persistent disk.
scp from old server to the VM /home/example_account for the first account. Realized scp does not follow symlinks (oops) and therefore the files went to the boot drive instead of the disk.
I suppose I could scp to /mnt/disks/my-persistent-disk and manage the symlinks and folders. Would this pose a problem? Would making an image of the VM with this configuration carry over to new instances (with autoscaling etc)?
Attempt #2, Mounting into /home.
Looking for a more 'natural' configuration that works with ftp, scp etc, I mounted the disk in /home/example_account
$ sudo mkdir -p /home/example_account
$ sudo mount -o discard,defaults /dev/sdc /home/example_account
$ sudo chmod a+w /home/example_account
#set the UUID for mounting at startup
$ sudo blkid /dev/sdc
$ sudo nano /etc/fstab
$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 10G 0 disk
└─sda1 8:1 0 10G 0 part /
sdc 8:32 0 200G 0 disk /home/example_account
scp from old server to the VM in the /home/example_account works fine. Yay. However, I would like to have more than just 1 folder in the /home directory. I suppose I could partition the disk but this feels a bit cumbersome and I'm not exactly sure how many accounts I will use in the future.
Attempt #3, Mount as /home
I felt the best solution was to have the persistent disk mount as the /home directory. This would allow for easily adding new accounts within /home without symlinks or disk partitions.
Attempted to move /home directory to /home.old but realized the Google Cloud Compute Engine would not allow it since I was logged into the system.
Changed to root user, but still said myusername#instance was logged in and using the /home directory. As root, I issued pkill -KILL -u myusername and the SSH terminated - apparently how the Google Cloud Compute Engine works with their SSH windows.
As I cannot change the /home directory, this method does not seem viable unless there is a workaround.
My thoughts:
Ideally, I think #3 is the best solution but perhaps there is something I'm missing (#4 solution) or one of the above situations is the preferable idea but perhaps with better execution.
My question:
In short, how to I move an old server's data to a Google Cloud VM with a persistent disk?