File is larger than maximum file size supported

[semperfidelis]

HI everybody,

We have a  below error when trying make snapshot:

• Create virtual machine snapshot VIRTUALMACHINE File <unspecified filename> is larger than the maximum size supported by datastore '<unspecified datastore>'
  
• File is larger than the maximum size supported by datastore
  

Issue is list in http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1012384

..But i don t understand what happen in my case for my FILE SERVER:

Here is my configuration:

• . VSPHERE 4.1
  

• My  datastore VMFS3 have 800MB, and block size 4MB (so  Maximum File Size 1TB )
  

• A file server is created inside, 30GB for System (c:) and a VIRTUAL RAW DISK attach capacity  1TB.
  

• The raw disk is  full of more 90%...only 60GB free space.
  

Problem:

We can t create a snapshot with message <unspecified filename> is larger than the maximum size supported by datastore '.

NOTICE:

Strangely i can create a snapshot of another virtual machine with same configuration at difference that (virtual) raw disk is not full with only 300MB used on the 1TB.

Has somebody can explain me how limit is really evaluating by the vsphere client ?

Thanks 

[a_p_]

Welcome to the Community,

as mentioned in the KB article you posted, the maximum virtual disk size (the same applies to virtual RDMs) in order to be able to create snapshots is 1,016 GB on a datastore with a 4MB block size. Please provide the latest vmware.log for both VM's to see what's the difference.

André

[sa2057]

Hi,

"My  datastore VMFS3 have 800MB, and block size 4MB (so  Maximum File Size 1TB )"

Increase the size of VMFS3 datastore and take a snapshot.

Thanks

SA

[a_p_]

@sa2057

Why do you think this would help? Can you please explain!

André

[sa2057]

This failure occurs when the snapshot file at its maximum size is unable to fit into a datastore. Starting with ESX/ESXi 4.0 compare the maximum size of a snapshot redolog file with the maximum size of files on the datastore. The redolog file may not work correctly once it reaches the maximum size of the datastore. If the file could grow beyond the maximum size, ESX/ESXi cancels the Create Snapshot operation and displays this error instead.

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1012384

I faced the same error msg with one of  my file server with  1.5 TB RDM in virtualmode. Fixed the problem after increasing the size of the datastore( VM loacted)

Question is  RDM is in virtual mode/ physical mode?

Thanks

SA

[Duncan Epping]

You cannot create a snapshot because it can grow larger than the size of your VMFS volume.

[iw123]

Hi,

Could you confirm that your RDM is in virtual mode?

To take a snapshot you must have enough space to accomodate the disk, at its possible maximum size.

See KB article below:

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1012384

Hope this helps

[semperfidelis]

Thanks you everybody for the responses;

RDM is in virtual Mode,iw123; sure.

SA do  i understand that to take my snapshot the LUN must have same or more  size that the RDM disk which will be attached. So if one day i want  attached for example a RDM of 2TB, the datastore will have to be  increase too...?

sa2057, for your file server, can you tell me what size have you set in your LUN to attach your  1.5 TB RDM...?

In  theory, just for understand, during a snapshot, vmware does it take  into account the disk space used, or the total disk capacity (RDM  include) ..?

In log file following the error is: Requested  file size (1108118456348) larger than maximum supported filesystem file  size (1099511627776)

Note:

My virtual machine currently state:

C:(SYSTEM)
20.5GB   used
9.38GB   free

D:  ( RDM  )
958GB    used

65.2GB   free

I  will try to increase block size to 8MB  in first step, and the second  step see result when  increasing size of datastore in another test.
Somebody advised  me to avoid to create LUN  greater than 800MB size for best performance; what do you think about it..?

(Not important, and not for this community, but  somebody uses VEEAM as backup solution, which needs take snapshot across vmware before  backup start ?)

[sa2057]

Hi,

Here are the details ...

We have couple of  file servers running on windows 2008 R2 on ESXi 4.1 with Veeam B&R v5

Vm details

Datastore: 700 GB - 8 MB block size ( I have other file servers store on the  same datastore)

System drive: 40 GB

10 LUNs - RDM in virtual mode - Luns starting from min 200 GB - Max 1.94 TB ( we have to keep these maximum's because orginally they were hosted on windows 2008 physical server and we had setup windows hard storage restrictions on each LUN not to exceed 85% )

I run weekly backup's on each LUN by excluding disk option in Veeam

All works fine

-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

In  theory, just for understand, during a snapshot, vmware does it take  into account the disk space used, or the total disk capacity (RDM  include) ..?

In log file following the error is: Requested  file size (1108118456348) larger than maximum supported filesystem file  size (1099511627776)

In your case for better understanding, pickup a working  file server i.e., that doesn't complain any snapshot issues, take a snapshot and have a quick look on the storageviews tab so that you can see the current snapshot size allocated on the datastore.

Thanks

SA

[a_p_]

As you may have read in my previous posts, I don't agree with the other posters. The important point is NOT the size of the VMFS datastore, it's just the maximum supported file size based on the block size!

In your case, the RAW LUN has a size of  approximately 1,024GB (958GB used + 65.2GB free + partition overhead). Snapshot files are sparse files which - in addition to the user data - contain metadata. This is why the maximum possible size of the snapshot file requires the 1108118456348 bytes (~1,032GB) which is too large for a datastore with a 4MB block size (1099511627776 bytes = 1,024GB). The maximum virtual disk size (or RAW LUN size) - in order to be able to create snapshots - in your case is ~1,016GB as mentioned in the KB you posted.

To resolve this issue you either need to migrate the data to another, smaller RAW LUN to replace the current one or migrate the VM's parent folder to a datastore with an 8MB block size (ESXi 4 and earlier create snapshots in the parent folder by default). Another option - although this might make things more complex - is to set the "workingdir" to a folder on a datastore with an 8MB block size (see e.g. http://kb.vmware.com/kb/1002929)

André

[KentNSK]

I am also facing a similiar problem, I have a 1950GB of vmdk on a 8MB block, and everytime I try to snapshot it failed with the same error message in the subject.

After reading lot of information, I done some testing with my limited resource and the findings as below:

Setting:

DS1 150GB, (1MB Block)

DS2 2TB, (8MB Block)

A VM (No i/o) is created in DS1 with 20GB, and a vmdk of 1950GB in DS2 is attached to the vm.

When I snapshot, it failed. (Default snapshot at DS1 with 1MB block)

Later I changed the snapshot directory to DS2 with 8BM block, and yeah, it works.

I slowly increase my vmdk size from 1950GB, and the max I reach is 2000GB.

When I come back to the production environment at customer site, he has 3 VM with

VM1 with 1950GB vmdk, and OS DS has 300GB free

VM2 with 1000GB vmdk, and OS DS has 300GB free

VM3 with 500GB vmdk, and OS DS has 700GB free

However, all 3 VMs are unable to snapshot, they all returned the same message.

I suggested to format the OS DS with 8MB block, but customer wants to be affirmed that this will really works before he reshuffles the VMs in order to get a DS with 8MB block ready for the OS and snapshot directory.

Can anyone advice? My question in summary:

Will a DS where the VM resides need to be 8MB block in order to allow snapshot to be taken with a vmdk of 2000GB attached to the VM?

Many thanks.

Kent