Really high disk i/o !!

Richard Kearsley richard at
Mon Jun 16 14:13:12 UTC 2014

On 16/06/14 12:49, shahzaib shahzaib wrote:
>  8MB/s w/r should not be issue for 12X3TB SATA HDD. Maybe i need to 
> tweak some nginx buffers or kernels in order to reduce the high io wait ?
if you have a high number of concurrent connections and/or use 
limit_rate, then expect hdd (sata or sas) to quickly run out of iops
tip from me: use nmon (linux) to see the real time status of your disks. 
If they are wrapped up in iowait then you need a faster seeking disk 
(e.g. ssd because sas won't give you a significant amount extra)
if only one of them is in iowait then it's probably a dead/dying disk

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