I recently upgraded Fedora Server (F) v36 to v37. The F36 server had a volume group consisting of three physical drives combined to form a storage pool, which I named “BigDrive”. During the upgrade the logical volume information seems to have been lost and BigDrive didn’t appear or mount in the F37 server. I’ve been unable to find any backup logical volume information. At present the 3 drives are installed on the F37 server. I would welcome advise on how to recombine the three drives, recover the logical volume information, and access the data stored in the shared pool. Can anyone suggest a process to do that, or a utility that could rebuild the storage pool from the physical drives?
I haven't found any helpful information in the various Fedora documentation or usual websites that don't reference using the backed up logical volume information which somehow didn't survive the upgrade process. This is because the OS hard drive was wiped and repartitioned as part of the upgrade. The drives that formed the storage pool were not formatted, nor do they store any OS or application files. They were purely data storage.
Related
I had a neo4j 3.5 enterprise edition running in a kubernetes cluster.
The cluster was deleted by error with any chance to make a recent neo4j database backup.
The only related things remaining to the old database are three Persistent Disk in the Google Cloud Compute Engine.
Is it possible to recover o restore the data stored in them? How?
The disk detail:
{"kubernetes.io/created-for/pv/name":"pvc-fd4fe6eb-2c24-11ea-bd38-42010a8e0228",
"kubernetes.io/created-for/pvc/name":"datadir-neo4j-neo4j-core-2",
"kubernetes.io/created-for/pvc/namespace":"default"}
The Secret storing the old password is lost.
Thanks
You probably need to first identify which disk hold the <neo4j-home>/data directory. Then create a snapshot of this disk (to be safe). Finally, you start a new neo4j pod by create a volume from the snapshot and mount to <neo4j-home>/data.
Cloud platforms like Linode.com often provide hot-pluggable storage volumes that you can easily attach and detach from a Linux virtual machine without restarting it.
I am looking for a way to install Postgres so that its data and configuration ends up on a volume that I have mounted to the virtual machine. The end result should allow me to shut down the machine, detach the volume, spin up another machine with an identical version of Postgres already installed, attach the volume and have Postgres work just like it did on the old machine with all the data, file system permissions and server-wide configuration intact.
Is such a thing possible? Is there a reliable way to move installations (i.e databases and configuration, not the actual binaries) of Postgres across machines?
CLARIFICATION: the virtual machine has two disks:
the "built-in" one which is created when the VM is created and mounted to /. That's where Postgres gets installed to and you can't move this disk.
the hot-pluggable disk which you can easily attach and detach from a running VM. This is where I want Postgres data and configuration to be so I can just detach the disk (after shutting down the VM to prevent data loss/corruption) and attach it to another VM when I want my data to move so it behaves like it did on the old VM (i.e. no failures to start Postgres, no errors about permissions or missing files, etc).
This works just fine. It is not really any different to starting and stopping PostgreSQL and not removing the disk. There are a couple of things to consider though.
You have to make sure it is stopped + writing synced before unmounting the volume. Obvious enough, and I can't believe you'd be able to unmount before sync completed, but worth repeating.
You will want the same version of PostgreSQL, probably on the same version of operating system with the same locales too. Different distributions might compile it with different options.
Although you can put configuration and data in the same directory hierarchy, most distros tend to put config in /etc. If you compile from source yourself this won't be a problem. Alternatively, you can usually override the default locations or, and this is probably simpler, bind-mount the data and config directories into the places your distro expects.
Note that if your storage allows you to connect the same volume to multiple hosts in some sort of "read only" mode that won't work.
Edit: steps from comment moved into body for easier reading.
start up PG, create a table put one row in it.
Stop PG.
Mount your volume at /mnt/db
rsync /var/lib/postgresql/NN/main to /mnt/db/pg_data and /etc/postgresql/NN/main to /mnt/db/pg_etc
rename /var/lib/postgresql/NN/main and add .OLD to the name and do the same with the /etc
bind-mount the dirs from /mnt to replace them
restart PG
Test
Repeat
Return to step 8 until you are happy
We're planning to migrate our software to run in kubernetes with auto scalling, this is our current infrastructure:
PHP and apache are running in Google Compute Engine n1-standard-4 (4 vCPUs, 15 GB memory)
MySql is running in Google Cloud SQL
Data files (csv, pdf) and the code are storing in a single SSD Persistent Disk
I found many posts that recomments to store the data file in the Google Cloud Storage and use the API to fetch the file and uploading to the bucket. We have very limited time so I decide to use NFS to share the data files over the pods, the problem is nfs speed is slow, it's around 100mb/s when I copying the file with pv, the result from iperf is 1.96 Gbits/sec.Do you know how to achieve the same result without implement the cloud storage? or increase the NFS speed?
Data files (csv, pdf) and the code are storing in a single SSD Persistent Disk
There's nothing stopping you from volume mounting an SSD into the Pod so you can continue to use an SSD. I can only speak to AWS terminology, but some EC2 instances come with "local" SSD hardware, and thus you would only need to use a nodeSelector to ensure your Pods were scheduled onto machines that had said local storage available.
Where you're going to run into problems is if you are currently just using one php+apache and thus just one SSD, but now you want to scale the application up and it requires that all php+apache have access to the same SSD. That's a classic distributed application architecture problem, and something kubernetes itself can't fix for you.
If you're willing to expend the effort, you can also try any one of the other distributed filesystems (Ceph, GlusterFS, etc) and see if they perform better for your situation. Then again, "We have very limited time" I guess pretty much means that's off the table.
I've got a Web Role on Azure with 2 Applications and 1 Virtual Directory.
1 Application is a backend, where admins can upload files, which are stored in the virtual directory (which is accessed by both applications).
Everytime I deploy a new version to Azure, all the uploaded content in the virtual directory is deleted - this is what I don't want!
So how is it possible to publish a new version without deleting all my user generated files?
I've already managed to update the application with WebDeploy. But this is only possible for the "main" application, and not the 2nd application (which is configured as a Virtual Application).
Thanks
You can't. The web role is recreated on deployment. It may also occur on hardware failure, azure redeploys your system if an instance fails. Redeploys a clean virtual machine and then deploys your app to it. You should never store data you want to keep on a web role. You need to use blob storage etc to store files you want to persist.
Virtual directories are stored on "Application" partition which is recreated on each upgrade - see this for more information. So the virtual directory folder is not the right place to store stuff you want preserved across upgrades. BTW the "Application" partition only has 1 gigabyte of space and some of that is used for storing your application binary code so you may find yourself in a "disk full" situation at some moment.
If you want to store some data which you don't mind sacrificing on rare occasions - like cached results - you may use "local resources" disk for that which will survive in-place upgrades and reboots. However it is not guaranteed to be preserved if your VM crashes - for such level of preservation you have to use persistent storage like blob storage for example.
Since you are talking about virtual directories and using web deploy to update application outside of the usual Azure package deployment mechanism, it sounds like your architecture/application might be more suited to a persistent VM role rather than a Web role. These are available on Azure in preview only at the moment.
http://www.windowsazure.com/en-us/home/scenarios/virtual-machines/
They let you have persistent storage that will survive a recycle. The storage is actually backed by blob storage, but it looks like a normal disk from the PVM.
Added more details at the bottom of the question.
We are testing deployment scenarios in Azure VM preview and have run into an issue.
Here is our scenario. We have a software stack that we use in all of our servers. We have created an image with all of that stack installed on an attached data drive. We have created a image of the VM that we can use as a template. Now what we want to do is to to create a VM based on that template and create a copy of the data drive and attach it to the newly created VM in an automated manner.
Our problem is that while we have found lots of information about creating drives, we can't find any guidance on how to copy the data drive using Azure for Powershell.
Any thoughts, code, or RTFMs happily accepted.
Cheers,
Terence
We have sucessfully created an operating system image that we can use to create VM's. But there is a data disk that holds our standard software stack that we want to reuse by copying it across VMs. The scenario that we are trying to implement is:
Create a VM from a standard VM image - PBIMaster
Attach a disk as F to that image called PBIMasterDisk
Install all of the software required for our app on F: (to big for the OS disk and besides sticking it on the OS disk seems messy)
Build an image from PBIMaster call it PBIMasterImage save it.
Create a new image from PBIMaster call it Node1
Copy PBIMasterDisk to a new Azure disk call it Node1Software disk
Attach Node1Softwaredisk to Node1 as F:
Since the image has the correct registry settings from the previous installs our stack is ready to go.
9 Add appropriate endpoints.
Rinse and repeat for each additional node.
Hopefully that makes our scenario clearer.
Thanks.
If I understood your objective correctly you already have uploaded two VHD in your subscription and you have also create a VM based on your OS Disk VHD1:
OS Disk (VHD1)
Data Disk (VHD2)
Now you want to copy VHD2 to VHD3 and then attach VHD3 to your VM (which is based on OS disk) via Powershell.
As of there is no powershell command which will let you copy DataDisk (VHD2) to another data disk (i.e VHD3)..
I haven't tried but you can use the following code to try copying your DataDisk:
http://blogs.msdn.com/b/windowsazurestorage/archive/2012/06/12/introducing-asynchronous-cross-account-copy-blob.aspx
This method does copy blobs directly at cloud storage level so there is no bandwidth usage towards on-premise and potentially zero cost if you are in same DC. Trying using the same subscription and see if that solves your problem.