Full storage space is not showing while connect with RHEV-M

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Hi,

 

I have created 20 GB storage LUN in Starwind software, but when i am discovering in RHEV-M it showong only 19 GB space. and after format again it decrease 4 GB space from my storage so we got only total 15 GB space.

 

any idea why i am getting less space.

 

 

regards

Rohit

ro
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Responses

DY Guru 5340 points
20 December 2011 4:17 PM

Hi Rohit,

 

This is absolutely normal. RHEV Storage Domains use ~4Gb for metadata. With the size of LUNs counted in hundreds of Gb and higher, this is neglectible.

 

See https://access.redhat.com/kb/docs/DOC-51832 for details regarding RHEV 2.2, things are slightly different with 3.0 but the general idea is the same

 

 

Hope this helps

Dan

ro Active Contributor 331 points
20 December 2011 4:37 PM

Hi Dan, 

Thanks for the information,

 

do you have any idea about p2v coverter tool of redhat, is redhat provide p2v converter tool and capicity planning tools?

ro Active Contributor 331 points
20 December 2011 4:42 PM

Hi Dan,

 

one more question, can we browse the attached datastore to check the VMs files and if our RHEVM is down then how to access the hypervisor?

 

Thanks in advance 

DY Guru 5340 points
20 December 2011 4:46 PM

Generally speaking, there should be no need to touch the files in the storage domains. Also, depending on the storage type used, the VM disk images are not always files - they can also be logical volumes. 

What would you want to access the VM disk images directly for?

ro Active Contributor 331 points
20 December 2011 4:53 PM

 

ok, i understand this, but some time for troubleshooting purpose may be need to access the VMs files.

 

and what will happen if my RHEVM manger server down can we access the hypervisor directly means without RHEVM and start and restart the vms directaly without rhevm manager 

DY Guru 5340 points
20 December 2011 5:04 PM

The storage domains are mounted on the hosts, and the mountpoints are browseable. However, it might be dangerous to meddle in the files, because the images are accounted for by RHEV-Manager, and if you change anything, the database on RHEV-M will not be in sync with the contents of the storage domains.

 

If the RHEv-M goes down, there are tools to start the VMs on the hosts directly, but again, to start a VM, you need to enable a host to access the VM's images, a task that is usually up to the RHEV-M.

 

To cut it short, the whole system is designed so that you will have no reason to go into the host command line. If you are concerned about RHEV-M going down, you have the option of building an HA setup of it, or to back it up frequently.

 

BTW, if the Manager goes down, the running VMs will keep on running, so a short outage will not affect a production system.

 

 

 

 

DY Guru 5340 points
20 December 2011 4:41 PM

P2V is under development. See this post about early non-production version availability: http://rwmj.wordpress.com/2011/12/05/p2v-and-v2v-new-release/

 

As for capacity planning, it sounds like a feature request, can you elaborate on what exactly you want to see in such a tool?

ro Active Contributor 331 points
20 December 2011 4:48 PM

 

Just like a VMware capacity planner or CIRBA, is there any tool which is provided by redhat ro recommended by redhat to analyses the physical servers capacity.

Because before implementing the hypervisor solution we have to analyses the performance of the servers and we have to check this server is good for vertualization or not.

rh Red Hat Guru 1569 points
21 December 2011 5:50 PM

Just stay tuned :)