[ec2-beta] Understanding Disk/Partitions Distribution in ami-18d73071

[Eric Hammond]

Luis:

umount will not complete if any process holds an open file in the file
system.

One common cause is to have the current working directory of a shell be
on the mount (e.g., cd /home/ubuntu/bin).

You can often find the culprit using a command like

  lsof | grep /home/ubuntu/bin

Where the last parameter is the mount point.

--
Eric Hammond
ehammond at thinksome.com



Luis Ibanez wrote:
> 
> 
>    Thanks to all of you for your suggestions.
> 
> 
> I followed the path of creating an EBS volume of 5Gb and
> then mounting it into a sub-directory of
> 
>                /home/ubuntu/bin
> 
> Then I built our software in that directory and submitted
> the test suite to our Dashboard:
> http://www.cdash.org/CDash/index.php?project=Insight
> (the build from the site:  "cirrus002.amazon.cloud.kitware").
> 
> That worked very smoothly.
> 
> ---
> 
> In retrospective, it makes a lot of sense to separate
> the instance itself from the storage of user data.
> 
> Your explanations were very helpful.
> 
> 
> ---
> 
> BTW: I had trouble unmounting the EBS volume.
>      When calling umount, it kept reporting that
>      the device was busy. I end up terminating the
>      instance...
> 
>      Have any of you seen similar behavior ?
> 
>      Did I missed to do something before umounting
>      the volume ?
> 
> 
>    Thanks again,
> 
> 
>       Luis
> 
> 
> -------------------
> Eric Hammond wrote:
>> Luis:
>>
>> EC2 instances are limited to 10GB on the root (/) partition.
>>
>> There is about 150 GB free under /mnt on small instances.  Large and
>> extra large instances have a lot more space, most of which is not even
>> formatted or mounted.
>>
>> For more information see:
>>
>>   http://ec2types.notlong.com
>>   http://ec2storage.notlong.com
>>
>> This local storage is called "ephemeral storage" by Amazon and it
>> disappears when the instance is terminated or fails.
>>
>> As Rodney points out, for persistent storage that lives beyond the life
>> of an EC2 instance, you will want to investigate Elastic Block Store
>> (EBS):
>>
>>   http://ec2ebs.notlong.com
>>
>> -- 
>> Eric Hammond
>> ehammond at thinksome.com
>>
>>
>>
>> Luis Ibanez wrote:
>>
>>> First of all,
>>> Thanks a lot for making these Ubuntu image available.
>>>
>>> This is great !.
>>>
>>>
>>> -- 
>>>
>>> Background:
>>>
>>> I'm using the ami-18d73071 in oder to setup a machine
>>> for testing Nightly builds of one of our open source
>>> packages (www.itk.org).
>>>
>>> My first try was to download the source code to the
>>> "/home/ubuntu" directory, and to try to build it right
>>> there.
>>>
>>> However, it turned out that the size of the "/" directory
>>> is rather small.
>>>
>>> Here is what I see with "df"
>>>
>>> Filesystem           1K-blocks      Used Available Use% Mounted on
>>> /dev/sda1              1548144    839580    629924  58% /
>>> tmpfs                  3681752         0   3681752   0% /lib/init/rw
>>> varrun                 3681752        68   3681684   1% /var/run
>>> varlock                3681752         0   3681752   0% /var/lock
>>> udev                   3681752      2516   3679236   1% /dev
>>> tmpfs                  3681752         0   3681752   0% /dev/shm
>>> /dev/sdb             433455904    840800 410596800   1% /mnt
>>>
>>> so the "/" partition was full before finishing
>>> building half of the package.
>>>
>>>
>>> ---
>>>
>>> My question is then:
>>>
>>>    What will be the recommended location in the file system
>>>    of the instance where I could put a source+binary tree
>>>    that may reach the 3 to 4 Gigabytes ?
>>>
>>>
>>> ---
>>>
>>> Should I think that these files should rather go into a storage
>>> bucket and that I should mounted and unmounted every time that
>>> I launch the instance ?
>>>
>>>
>>>
>>>   Thanks for any advice,
>>>
>>>
>>>      Luis
>>>
>>>
>>>
>>
>>
>