[DRBD-user] A simple test

[Ryan Steele]

Lars Ellenberg wrote:
> On Wed, Jun 13, 2007 at 09:04:41AM -0400, Ryan Steele wrote:
>   
>> Ben and Mark,
>>
>> Thank you for your input.  I am currently fixing up my FAI configs such 
>> that they do not create an MD device out of two of the unused 
>> partitions, as I don't see any need to have the DRBD meta-disk striped 
>> or mirrored (unless someone has any good reason pointing to the 
>> contrary, e.g. significant performance gains).
>>
>> Pending that, I will re-test with drbddisk and Filesystem.  Again, I 
>> appreciate the advice and hopefully this will yield successful results!
>>     
>
> um.
> saying "hey, I use drbd, there is no need for raid underneath"
> is similar to "hey, I have raid, there is no need for backups anymore".
>
> and yes, you get a performance gain from using raid1,
> because reads can be striped.
>
>   

Well, it's only 128 MB of information, right?  It's not like my 
cylinders arms are going to be thrashing all over the disk searching for 
meta information, so how much of a performance gain would I _really_ get 
from striping those devices?  And, just to be clear, all of my other 
devices (including the drbd data devices) are RAIDed, so you're a bit 
off the mark by accusing me (even implicitly) of saying "I use DRBD, 
there is no need for RAID underneath."  I just wasn't sure if it was 
necessary for improved performance with regards to the meta-disk.  We 
learn by asking questions, right?

In any case, thanks for the input, I appreciate it.

Best Regards,
Ryan