[Ocfs2-users] Lots of questions & lustre

[Sunil Mushran]

Jeffrey W. Baker wrote:

>Can you mmap a file on OCFS2 for reading?
>  
>
Yes

>Can you execute programs off OCFS2?
>  
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Yes

>Can two hosts open the same file O_APPEND, with correct results?
>  
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Not tried it personally. But it should work. File a bug if it does not. :)

>Can the OCFS2 volume be on top of an LVM device?  MD?  How would that
>work?
>  
>
The LVM would have to be cluster aware. While we have not tested this as 
yet,
there is no reason why this should not work.

>Can you have 32-bit and 64-bit nodes in the same cluster?  Nodes with
>different page sizes (e.g. Itanium)?
>
>  
>
Yes. We support x86, x86-64 and IA64. All can access the same fs 
concurrently.

>Is there a limit on the size of the volume on 64-bit hosts?  On 32-bit?
>  
>
The limit is 4 billion clusters. So if the cluster size is 1MB, it's 4 
Peta bytes.

>How many inodes will I get from e.g. a 4TB volume?
>  
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The inodes are allocated from a dynamically growing space. That is, we 
do not
pre-allocate inode space. Each inode is atleast a block.

>Is there a subdirectory limit?
>  
>
Unless vfs has some limits. no. Not that I am aware of.

>Where can I find some comparative benchmarks?  How close to wire speed
>can OCFS2 achieve on a single host?  Cluster-wide?  How many
>stats/second can it do?  How much net traffic is caused by a given
>amount of fibrechannel traffic?
>  
>
We don't have any official benchmarks as yet.

>Can you safely deliver mail on OCFS2?
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Care to expand.