Frequently Asked Questions (FAQ)

Frequently Asked Questions FAQ

This is the thread for frequently asked questions. The list owners will move postings in here as appropriate.
 
Frequently Asked Questions FAQ

This is the "frequently asked questions" forum, the place you go when you have a question that may have already been answered. You also have the option of replying to this post with a question that has not been answered. If a question seems appropriate, it will be added to the other questions already present. Make sure you read all the current questions before you ask a new one, as asking a question already there because you havent read will results in an increase of your warning level.Remember to ask any questions you may have. This topic will remain open for the immediate future. Have fun guys.
 
STOP VS SNAPSHOT VS SUSPEND

I searched the the forum and the wiki but cannot find a clear description of these different backup modes. What are the pros and cons of each when would it be wise to chose one over the other etc. Perhaps this has already been answered elsewhere.. please direct me.

Thanks.

Petrus4
 
Petrus4 said:
STOP VS SNAPSHOT VS SUSPEND

I searched the the forum and the wiki but cannot find a clear description of these different backup modes. What are the pros and cons of each when would it be wise to chose one over the other etc. Perhaps this has already been answered elsewhere.. please direct me.
Click to expand...

see 'man vzdump'
 
dietmar said:
see 'man vzdump'
Click to expand...

Thanks! I had looked at 'man vzdump' in version Proxmox-VE 1.1 but there was minimal info there. I noticed that in version 1.4 'man vzdump' has more info and answers a most of my questions. I understand that each mode has more or less down time associated with them. Stop mode = long down time, Suspend Mode = multiple short down times, Snapshot mode = no down time. What I am looking for clarity on is the quality of the backups with each mode. Perhaps an example might help clarify this:

In the case of backing up a Moodle webserver (MySQL, Apache) were users are uploading documents and changing content during a backup.

What would be the differences in quality and consistency for a backup made with each mode?

thanks

Petrus
 
Petrus4 said:
Thanks! I had looked at 'man vzdump' in version Proxmox-VE 1.1 but there was minimal info there. I noticed that in version 1.4 'man vzdump' has more info and answers a most of my questions. I understand that each mode has more or less down time associated with them. Stop mode = long down time, Suspend Mode = multiple short down times, Snapshot mode = no down time. What I am looking for clarity on is the quality of the backups with each mode. Perhaps an example might help clarify this:

In the case of backing up a Moodle webserver (MySQL, Apache) were users are uploading documents and changing content during a backup.

What would be the differences in quality and consistency for a backup made with each mode?

thanks

Petrus
Click to expand...

Anything changing 'during' the backup will not be backed up in any of the modes. With the first two, the server would essentially be unavailable for any user access during the backup. With snapshot mode, a snapshot of the VM is made at the beginning of the backup. This snapshot of data is what gets backed up. Anything that changes after the snapshot is taken (while the backup is created), will NOT be backed up.
 
tlphipps said:
Anything changing 'during' the backup will not be backed up in any of the modes. With the first two, the server would essentially be unavailable for any user access during the backup. With snapshot mode, a snapshot of the VM is made at the beginning of the backup. This snapshot of data is what gets backed up. Anything that changes after the snapshot is taken (while the backup is created), will NOT be backed up.
Click to expand...

Ok thanks tlphipps. So as I understand it now: All modes offer the same quality backups. Snapshot mode allows user to continue to use the server during the backup.

What are the average time differences between the modes given a set amount of data with similar server load?
 
Petrus4 said:
Ok thanks tlphipps. So as I understand it now: All modes offer the same quality backups. Snapshot mode allows user to continue to use the server during the backup.

What are the average time differences between the modes given a set amount of data with similar server load?
Click to expand...

I've only used the snapshot method myself, so can't provide comparisons. But in my experience the time to complete the backup seems to be determined most by the speed of the disks you're reading from and writing to for the backups. I wouldn't really expect there to be much difference between the various methods.
 
I have an existing FreeBSD 7.2 installation on a server. I want to install Proxmox VE on second HDD, run KVM-virtualized FreeBSD from the first HDD and move all services to some OpenVZ-containers one by one, making all movements as transparent as I can. How can I do it if it's possible at all?
 
I would unplug the freebsd hdd during installation of Proxmox VE to eliminate any risk. then start the bsd with KVM and begin migration tasks.
 
Help:
I have SSD on my two servers and need to do something regarding to the "TRIM" command, I am planning to run these server 24/7 and SSD w/o TRIM is not a good idea. I know to support trim I need two things:
1- a linux kernel newer than the .33 this is no problem.
2- I need ext4 in order for TRIM to work, THIS IS A PROBLEM.

I need to know how to get ext4 in proxmox, is it before installing or is it after installed that I need to convert to ext4. I know I can only use KVM but that is ok.

Please Helpppppp.
 
pls do not double post.
 
is it only possible to access Proxmox through the webinterface? Is there a possibility of connecting the server to a monitor and using it from there?
 
CLI is available for use with Keyboard and monitor connected to the Proxmox server.

Alternatively, it may be possible to install a full Debian Squeeze with desktop capability and mouse and then install ProxMox on it. The default ISO will not be useful here.
 
It is really amazing how cloud computing works. Imagine before, you have to install proprietary software on each machine for you to be able to carry out the job, which would really cost you as software license is really expensive. Now you can just publish it through the network and have the connected workstations load it of from there. This could really change the computer industry as they do not have to rely on software that cost a great deal of money.
 
CT vs VM, what's the difference?

I am really new to this virtualization stuff, however, I ran a server with v1.9 and testing now v2.0rc1.
Can someone tell a N00b where the difference between CTs and VMs is and what I should choose to use mainly?
In v1.9 they all were called VMs. Even if I install from ISO or through a template....

Thank you!
 
Re: CT vs VM, what's the difference?

olma said:
I am really new to this virtualization stuff, however, I ran a server with v1.9 and testing now v2.0rc1.
Can someone tell a N00b where the difference between CTs and VMs is and what I should choose to use mainly?
In v1.9 they all were called VMs. Even if I install from ISO or through a template....

Thank you!
Click to expand...

as i know, CT means container, your vitual machin will be created with openvz, a so called paravitualization technology. the other one, VM, should be full virtualization with kvm. please google about the differences between para- and full-virtualization. the fantastic thing with proxmox is that you can choose what tecnology you need. i use CT for webservers and VM for file server. but there are surely further applications. i am not a real expert as well.

bye
 
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