[one-users] sparse files as partitions in OpenNebula?

Ruben S. Montero rubensm at dacya.ucm.es
Wed Nov 24 14:23:30 PST 2010


Take a look at ImageRepository.rb line 197

On Wed, Nov 24, 2010 at 10:03 PM, Steven Timm <timm at fnal.gov> wrote:

>
> A followup--
> when I try to run the mkfs command by hand on a copy of the sparse
> file from the repository here is what I get:
>
> /sbin/mkfs.ext3 ./testsparsefile
> mke2fs 1.39 (29-May-2006)
> ./testsparsefile is not a block special device.
> Proceed anyway? (y,n)
> Filesystem label=
> OS type: Linux
> Block size=4096 (log=2)
> Fragment size=4096 (log=2)
> 262144 inodes, 524288 blocks
> 26214 blocks (5.00%) reserved for the super user
> First data block=0
> Maximum filesystem blocks=536870912
> 16 block groups
> 32768 blocks per group, 32768 fragments per group
> 16384 inodes per group
> Superblock backups stored on blocks:
>        32768, 98304, 163840, 229376, 294912
>
> Writing inode tables: done
> Creating journal (16384 blocks): done
> Writing superblocks and filesystem accounting information: done
>
> This filesystem will be automatically checked every 36 mounts or
> 180 days, whichever comes first.  Use tune2fs -c or -i to override.
> bash-3.2$ ls -lrt
> total 10349388
> -rw-r--r-- 1 timm fnalgrid  2147483649 Nov 24 14:42
> c440fa087fda2ddfecee250da48659db675da0e5
> -rw-rw---- 1 timm fnalgrid 10485760000 Nov 24 14:50
> 7bf1f760a574f34a88213010ed76ef632ccffbea
> -rw-r--r-- 1 timm fnalgrid  2147483649 Nov 24 14:59 testsparsefile
> bash-3.2$ du -s ./testsparsefile
> 99352   ./testsparsefile
> bash-3.2$ du -s ./c440fa087fda2ddfecee250da48659db675da0e5
> 16      ./c440fa087fda2ddfecee250da48659db675da0e5
> bash-3.2$ file ./testsparsefile
> ./testsparsefile: Linux rev 1.0 ext3 filesystem data (large files)
>
> So it could be that the script that is calling the mkfs command  is not
> expecting the y/n prompt and that is what is giving the error.  Adding
> the -F option to the mkfs would fix that.  Where is the corresponding
> ruby file that is calling the mkfs?
>
> Steve Timm
>
>
>
>
>
> On Wed, 24 Nov 2010, Steven Timm wrote:
>
>
>> Two surprises here:
>>
>> 1) oneimage help doesn't list a "create" subcommand at all, just oneimage
>> register.
>>
>> 2) I made a fresh install of opennebula on a clean machine
>> with nothing else installed and I still get the same error I got before,
>> no matter if I use oneimage create or oneimage register.
>>
>> bash-3.2$ oneimage create datablock_test.one
>> Error: mkfs Image: in mkfs command.
>>
>> What is it trying to do at this stage?
>> Note that it *did* make a sparse data file in the image repo at about that
>> time but seems to have failed to make the file system inside of it.
>> ls -lh reports a file size of 2.1G, du -s reports a usage of just 16K.
>>
>> We are using the stock ruby that comes with sci. linux 5.5
>>
>> bash-3.2$ rpm -q ruby
>> ruby-1.8.5-5.el5_4.8.x86_64
>>
>> Also note--if I need to create an OS image I can do it.
>>
>> bash-3.2$ oneimage create kernel.img
>> bash-3.2$ oneimage list
>>  ID     USER                 NAME TYPE              REGTIME PUB PER STAT
>> #VMS
>>  4     timm        Steve test OS   OS   Nov 24, 2010 20:46 Yes  No  rdy 0
>> bash-3.2$
>>
>>
>> On Wed, 24 Nov 2010, Ruben S. Montero wrote:
>>
>>  Hi
>>>
>>> Yes in this case there should not be any path. Here it is working:
>>>
>>>>            <
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>   img>
>>> cat dblock.img
>>> NAME          = "Experiment results"
>>> TYPE          = DATABLOCK
>>> # No PATH set, this image will start as a new empty disk
>>> SIZE          = 2048
>>> FSTYPE        = ext3
>>> PUBLIC        = NO
>>> DESCRIPTION   = "Storage for my Thesis experiments."
>>>
>>>  oneimage create dblock.img
>>>>
>>>
>>>
>>>  oneimage create dblock.img
>>>>
>>> pc-ruben:img> oneimage list
>>>  ID     USER                 NAME TYPE              REGTIME PUB PER STAT
>>> #VMS
>>> ...
>>>  5    ruben   Experiment results   DB   Nov 24, 2010 20:30  No  No  rdy
>>>  0
>>>
>>> <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
>>>
>>>
>>> It may be a ruby version issue, which one are you using?
>>>
>>> About the other questions:
>>>
>>> a.- qcow2 feature is already in the source repo, and will be included in
>>> the
>>> upcoming OpenNebula 2.0.1.
>>>
>> Can we use qcow2 and persistent at the same time?
>>
>>  b.- there is not a relationship between the persistent attribute and the
>>> image format. When a image is declared as persistent only one VM is able
>>> to
>>> use it to prevent data inconsistencies in the image.
>>>
>>
>> That is what we would want in this case.
>>
>>  c.- spare images: I think I do not really understand your use case. Would
>>> not  a datablock do the job?
>>>
>>
>> A datablock would do the job if I could make it work.
>>
>> Steve
>>
>>
>>
>>> Cheers
>>>
>>> Ruben
>>>
>>> On Tue, Nov 23, 2010 at 9:38 PM, Steven Timm <timm at fnal.gov> wrote:
>>>
>>>  I am trying to create the example DATABLOCK volume
>>>> as shown on
>>>>
>>>> http://www.opennebula.org/documentation:rel2.0:img_template
>>>>
>>>> bash-3.2$ cat datablock_test.one
>>>> NAME          = "Experiment results"
>>>> TYPE          = DATABLOCK
>>>> # No PATH set, this image will start as a new empty disk
>>>> SIZE          = 2048
>>>> FSTYPE        = ext3
>>>> PUBLIC        = NO
>>>> DESCRIPTION   = "Storage for my Thesis experiments."
>>>>
>>>> bash-3.2$ oneimage register datablock_test.one
>>>> Error: mkfs Image: in mkfs command.
>>>>
>>>> What is missing?  Template reference page seems to
>>>> indicate that I need SOURCE or PATH required, but
>>>> what would be SOURCE if I just want to start with
>>>> a blank file system?
>>>>
>>>> ------------------------
>>>>
>>>> Also I  have more questions on the qcow2 format:
>>>> a) we are running opennebula 2.0, haven't there been some
>>>> bug reports that qcow2 isn't working with latest opennebula.
>>>> b) It's my understanding that qcow2 format does quick copy
>>>> on write, how does that mesh with a image that is persistent--i.e
>>>> in normal circumstances only one system would be using it?
>>>>
>>>> Does anyone know of a way to send a sparse image along with KVM
>>>> or can that only be done in Xen?
>>>> Steve
>>>>
>>>>
>>>>
>>>> On Fri, 12 Nov 2010, Ruben S. Montero wrote:
>>>>
>>>>  Hi
>>>>
>>>>>
>>>>> Yes OpenNebula supports that functionality. You can define spare file
>>>>> systems that can be created on the fly and then saved for later usage.
>>>>> There are two aspects to be considered:
>>>>>
>>>>> *Usage*
>>>>>
>>>>> This can be implemented with the new image repository using a
>>>>> DATABLOCK image, more information on this [1]. Also you can define a
>>>>> FS image to be a plain FS that will be created the first time and then
>>>>> can be reused, options for disks in [2]. If you use the image repo, be
>>>>> sure to make the image persistent, and when using the second option
>>>>> make sure to include SAVE=yes in the disk so you keep the changes.
>>>>> (Note that SOURCE in the previous image definitions may point to a
>>>>> block device)
>>>>>
>>>>> *Implementation*
>>>>>
>>>>> This depends on the storage architecture you are planning for your
>>>>> cloud. The images can be backed by a device (e.g LVM, you need to make
>>>>> the devices known to all the WNs) a shared FS (NFS is not an option
>>>>> but may be Ceph, GlusterFS or Lustre works in your setup). Also you
>>>>> can use qcow formats that will dynamically grow and may help to move
>>>>> the disk around. OpenNebula 2.0 can be used to implement these
>>>>> options. You may need to tune some of the drivers to match your system
>>>>> tough.
>>>>>
>>>>> Let me know if you need more help
>>>>>
>>>>> Cheers
>>>>>
>>>>> Ruben
>>>>>
>>>>> [1] http://www.opennebula.org/documentation:rel2.0:img_guide
>>>>> [2]
>>>>> http://www.opennebula.org/documentation:rel2.0:template#disks_section
>>>>>
>>>>> On Thu, Nov 11, 2010 at 8:00 PM, Steven Timm <timm at fnal.gov> wrote:
>>>>>
>>>>>
>>>>>> I have a user who has a need for 250GB of disk storage (eventually)
>>>>>> that he would like to migrate around with his VM.  NFS isn't
>>>>>> suitable for this application.  This is an application which will
>>>>>> start with a file base and then gradually grow.  On Amazon this
>>>>>> could be a use case for EBS but ONE doesn't have anything like that
>>>>>> as far as I can tell.
>>>>>>
>>>>>> My question, can I create an opennebula template that calls out
>>>>>> device "vdc" as a sparse file system eventually growable to 250 GB,
>>>>>> and migrate that and save that as necessary?  If so, how?
>>>>>> We are running opennebula 2.0 and using KVM as our hypervisor.
>>>>>>
>>>>>> Steve Timm
>>>>>>
>>>>>>
>>>>>> --
>>>>>> ------------------------------------------------------------------
>>>>>> Steven C. Timm, Ph.D  (630) 840-8525
>>>>>> timm at fnal.gov  http://home.fnal.gov/~timm/
>>>>>> Fermilab Computing Division, Scientific Computing Facilities,
>>>>>> Grid Facilities Department, FermiGrid Services Group, Assistant Group
>>>>>> Leader.
>>>>>> _______________________________________________
>>>>>> Users mailing list
>>>>>> Users at lists.opennebula.org
>>>>>> http://lists.opennebula.org/listinfo.cgi/users-opennebula.org
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>>  --
>>>> ------------------------------------------------------------------
>>>> Steven C. Timm, Ph.D  (630) 840-8525
>>>> timm at fnal.gov  http://home.fnal.gov/~timm/
>>>> Fermilab Computing Division, Scientific Computing Facilities,
>>>> Grid Facilities Department, FermiGrid Services Group, Assistant Group
>>>> Leader.
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>
>>
> --
> ------------------------------------------------------------------
> Steven C. Timm, Ph.D  (630) 840-8525
> timm at fnal.gov  http://home.fnal.gov/~timm/
> Fermilab Computing Division, Scientific Computing Facilities,
> Grid Facilities Department, FermiGrid Services Group, Assistant Group
> Leader.
>



-- 
Dr. Ruben Santiago Montero
Associate Professor (Profesor Titular), Complutense University of Madrid

URL: http://dsa-research.org/doku.php?id=people:ruben
Weblog: http://blog.dsa-research.org/?author=7
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