{Spam?} Re: [Ocfs2-users] Performance Problems while reading

[Egon Burgener]

Hi 

Am Mi, 2007-02-21 um 18.54 schrieb Sunil Mushran:
> And you are convinced that drdb's primary-primary is not the
> cause for the slowdown. ??
Yes, writing a file is fast. Reading a file has no influence on drbd.

We noticed, that reading a big file on one node while the other node
opened that file in RW mode but without writing anything is still fast.
If the writing node writes slowly to the file (e.g. a logline per
second) reading from the other node is also fast. As soon as the writing
speed increases (e.g. a logline per 1/3 second) reading blocks. While
tcpdumping all these scenarios we noticed, that the blocking scenario
produces much more connections (ocfs2 protocol).
Finally we tried to buffer the write operations and flushing it each
second. The result was, that writing many loglines per second did not
block the reading process on the other node.

cheers
Egon