On 11/15/09, Andrés J. Díaz <[email protected]> wrote: > Hi Israel > > 2009/11/15 Israel Garcia <[email protected]>: >> Hi list, I'm running collectd 4.7.2 on a xen domU(debian lenny) and >> on a Dual Intel 1.4GHz, RAID1 with 2x36GB SCSI 10,500RPM . I'm >> collecting information of more than 100 servers (a lot of rrd files), >> so cpu load is always at 100% iowait, the load is always over 3, disk >> is doing over 400 IOPS and 3MB/s througput. No more domU's are running >> in this dom0 server. How can I improve the performance in this server? >> Can you help me? > Hi Andres,
> The first step could be setting the filesystem properly. In my case > (i'm collecting data from more than 150 servers), I mount the rrd > directory with "data=writeback, commit=60, noatime, nodiratime". This > will be improve a bit the disk io. > OK. > The next step is setting the rrdtool plugin or rrdcached if you are using > this plugin. In my case I use directly rrdtool, and has the following > values: > > CacheFlush 7200 > CacheTimeout 900 > RandomTimeouts 10 > > You can get information about this parameters in collectd.conf(5) man page. > The RandomTimeouts was recently commited in collectd and I'm not > sure if it is available in 4.7.2 version :( > OK, I'll check is it available or not. I'll let you know. :-) > Finally, and how Josef says, check the interval on your config. In my case > we have an aggresive interval of 10s (we require a "real time monitoring" in > some situations), but usually values of 30s or greather will be enough for a > normal recollection. I've already changed Interval to 60 but the performance was not good. Do you think wit Interval over 60 there's isn't lost of data? > > One more thing. Xen hypervisor, AFAIK, drives the IO operations from VMs to > domU, so if you have a number of VM which works hard with disk you could > have a big bottleneck in the host. I was not working much with Xen, but I > heard creepy stories about the IO management of the domU.. :( You're right, but in my case I hace only one domU (collectd) in my server. Nothing else is running on dom0 either. thanks again Andres, regards Israel. > > Regards, > Andres > -- Regards; Israel Garcia _______________________________________________ collectd mailing list [email protected] http://mailman.verplant.org/listinfo/collectd
