If you have both systems to get some idea, can you get the `gluster profile info' output? That helps a bit to understand the issue.
On Thu, Feb 21, 2019 at 8:20 AM Kartik Subbarao <[email protected]> wrote: > We're running gluster on two hypervisors running Ubuntu. When we > upgraded from Ubuntu 14.04 to 18.04, it upgraded gluster from 3.4.2 to > 3.13.2. As soon as we upgraded and since then, we've been seeing > substantially higher iowait on the system, as measured by top and iotop, > and iotop indicates that glusterfsd is the culprit. For some reason, > glusterfsd is doing more disk reads and/or those reads are being held up > up at a greater rate. The guest VMs are also seeing more iowait -- their > images are hosted on the gluster volume. This is causing inconsistent > responsiveness from the services hosted on the VMs. > > I'm looking for any recommendations on how to troubleshoot and/or > resolve this problem. We have other sites that are still running 14.04, > so I can compare/contrast any configuration parameters and performance. > > The block scheduler on 14.04 was set to deadline and 18.04 was set to > cfq. But changing the 18.04 scheduler to deadline didn't make any > difference. > > I was wondering whether glusterfsd on 18.04 isn't caching as much as it > should. We tried increasing performance.cache-size substantially but > that didn't make any difference. > > Another option we're considering but haven't tried yet is upgrading to > gluster 5.3 by back-porting the package from Ubuntu 19.04 to 18.04. Does > anyone think this might help? > > Is there any particular debug logging we could set up or other commands > we could run to troubleshoot this better? Any thoughts, suggestions, > ideas would be greatly appreciated. > > Thanks, > > -Kartik > > _______________________________________________ > Gluster-users mailing list > [email protected] > https://lists.gluster.org/mailman/listinfo/gluster-users -- Amar Tumballi (amarts)
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