I have a query regarding the File Stripping.
I installed 1 MDS, 2 OSS/OST and 2 LustreClients(would be making it
namenode and datanodes). Now as I run the lfs utility for file
stripping:

[root@lustreclient1 ~]# lfs getstripe /mnt/lustre
/mnt/lustre
stripe_count:   1 stripe_size:    1048576 stripe_offset:  -1
/mnt/lustre/ebook
stripe_count:   1 stripe_size:    1048576 stripe_offset:  -1
/mnt/lustre/hadoop_tmp
stripe_count:   1 stripe_size:    1048576 stripe_offset:  -1

I understand that as of now stripe_count=1 denotes that its stripping
over just 1 OSS/OST.
Since I have 7 OSTs do I need to setstripe count to 7. What is the
exact command, if needed.

As I am comparing Hadoop over Lustre, will striping play a role here?
Please suggest.

On 3/20/13, Diep, Minh <minh.diep@intel.com> wrote:
>
>
> On 3/20/13 10:54 AM, "linux freaker" <linuxfreaker@gmail.com> wrote:
>
>>Yes, you are correct. I wrote lustreclient3 twice, instead of
>>lustreclient4.
>>I got your point on this.
>>
>>>while MDS and OSS/OST will be undisturbed and will
>>>neither be namenode/datanode.. am I right?
>>It can be namenode but should not be datanode since we are not
>>recommending mount lustre client on servers.
>>
>>You said it can be namenode. How is it possible?
>>Say, if I take MDS as namenode. In case of namenode, we usually take
>>mount point as /mnt/lustre. But there is no such mount point here in
>>MDS. Same for OSS / OST.
> Namenode only uses a small storage. You could do that with local disk,
> don't need lustre. However, if you use a lustre client as both name node
> and datanode, it's fine too.
>>
>>One more doubt is:
>>
>>You expressed .."If you have 2 oss with 6 OST each, resulting total of
>>12 disks, then you
>>might use 3 disks on each of 4 datanode (ie. Total 12 disks.)
>>However, you are using LVM. That's different."
>>
>>I dint understand why are we concerned regarding 3 disk on each of 4
>>namenode? Are you talking about Hadoop + HDFS here.
> Yes, to try to use comparable resources.
>
>>
>>Though I will go ahead and test the environment, and then come back
>>with more results meanwhile.
>>
>>Thanks for all the suggestion. Its really great to see such an active
>>mailinglist.
> No problem
>
> Thanks
> -Minh
>>
>>
>>
>>
>>On 3/20/13, Diep, Minh <minh.diep@intel.com> wrote:
>>>
>>>
>>> On 3/20/13 10:21 AM, "linux freaker" <linuxfreaker@gmail.com> wrote:
>>>
>>>>Just to understand it correctly.
>>>>If I have 1 MDS, 2 OSS with 6 OST each(created through LVM) and 4
>>>>lustreclients.
>>>>So, as per your statement, its equivalent to 1 NameNode(=>
>>>>LustreClient1) and 3 DataNode(=>lustreclient2, lustreclient3,
>>>>lustreclient3),
>>> Should be 4 datanode + 1 namenode. You had lustreclient3 twice?
>>>
>>>>while MDS and OSS/OST will be undisturbed and will
>>>>neither be namenode/datanode.. am I right?
>>> It can be namenode but should not be datanode since we are not
>>> recommending mount lustre client on servers
>>>>
>>>>All I dint get this point .."I would also keep the same total number
>>>>of OSTs and total number of disks on all datanodes." Can you please
>>>>clarify.
>>> If you have 2 oss with 6 OST each, resulting total of 12 disks, then you
>>> might use 3 disks on each of 4 datanode (ie. Total 12 disks.)
>>> However, you are using LVM. That's different.
>>>
>>> You can start out with what you have to see how the perf numbers turn
>>>out,
>>> but it's difficult to draw any conclusion if we are not comparing
>>> apple-to-apple.
>>>
>>> Thanks
>>> -Minh
>>>
>>>>
>>>>Regarding LUG, I will try to see if I can attend it.Thanks for sharing
>>>>it.
>>>>
>>>>On 3/20/13, Diep, Minh <minh.diep@intel.com> wrote:
>>>>> Hi,
>>>>>
>>>>> There isn't a simple or trivial comparison between Hadoop+HDFS and
>>>>> Hadoop+Lustre.
>>>>> A typical approach (IMHO) is keeping the same number of Lustre client
>>>>>with
>>>>> Hadoop datanode.
>>>>> I would also keep the same total number of OSTs and total number of
>>>>>disks
>>>>> on all datanodes.
>>>>>
>>>>>