[DRBD-user] A simple test

Ryan Steele steele at agora-net.com
Wed Jun 13 16:05:30 CEST 2007

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.

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,

More information about the drbd-user mailing list