Slow read operation on file -- configure SlowFileLatencyUs to change threshold\n #1247

[krishna pandey]

Hi Team,

i facing strange issue from last 2 day i am getting this messages in my logs every second which was working fine before a week.

[Tue Jan 19 15:33:23 2016] [error] [mod_pagespeed 1.9.32.10-7443 @30421] Slow read operation on file /pspeed_cache/mbhaskar/v2/bhaskar.com/http,3A/,2Fm.bhaskar.com/news-whf/JM-JKR-CN-this-is-the-chanakya-s-30-thought-5226081-PHO.html,3Fseq=24,: 110.455ms; configure SlowFileLatencyUs to change threshold\n

Below is my conf & filters

Version: 14: on

Filters
cw	Collapse Whitespace
dj	Defer Javascript
ea	Elide Attributes
fc	Fallback Rewrite Css 
hw	Flushes html
idp	Insert DNS Prefetch
ll	Lazyload Images
cj	Move Css Above Scripts
jm	Rewrite External Javascript
jj	Rewrite Inline Javascript

Options
  CriticalImagesBeaconEnabled (cibe)  False
  EnableCachePurge (euci)             True
  EnableRewriting (e)                 1
  FileCacheCleanIntervalMs (afcci)    3600000
  FileCacheInodeLimit (afcl)          500000
  FileCachePath (afcp)                /pspeed_cache/mbhaskar/
  FileCacheSizeKb (afc)               209715200
  LogDir (ald)                        /var/log/pagespeed
  LRUCacheByteLimit (alcb)            16384
  LRUCacheKbPerProcess (alcp)         1024
  RateLimitBackgroundFetches (rlbf)   False
  RewriteLevel (l)                    Pass Through
  SslCertDirectory (assld)            /etc/pki/tls/certs
  SslCertFile (asslf)                 /etc/pki/tls/cert.pem

Domain Lawyer
  http://*.bhaskar.com/ Auth

Invalidation Timestamp: (none)

Please help me with it as its increasing my iowait 

Filesystem                                  Size  Used Avail Use%   Mounted on

/dev/mapper/pspeed_cache-pspeed_cacheLV     493G  6.6G  461G   2%  /pspeed_cache

[Jeff Kaufman]

PageSpeed is logging this error because it's finding that reading that
file from its cache is taking 110.455ms. If you weren't getting this
before then something about your system has changed to where
/pspeed_cache is much slower than it was. This unknown cause is
probably also behind your iowait symptom.

You can hide the message by setting SlowFileLatencyUs to something
higher, like "ModPagespeedSlowFileLatencyUs 200000", but all this will
do is keep PageSpeed from logging the error, it won't actually fix
anything.

> --
> You received this message because you are subscribed to the Google Groups
> "mod-pagespeed-discuss" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to mod-pagespeed-di...@googlegroups.com.
> To view this discussion on the web visit
> https://groups.google.com/d/msgid/mod-pagespeed-discuss/29cf0c0d-334f-4d01-b58d-33f39ad9da6f%40googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.