xfs
[Top] [All Lists]

Problem about very high Average Read/Write Request Time

To: xfs@xxxxxxxxxxx
Subject: Problem about very high Average Read/Write Request Time
From: quanjun hu <huquanjun@xxxxxxxxx>
Date: Sat, 18 Oct 2014 17:26:40 +0800
Delivered-to: xfs@xxxxxxxxxxx
Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:date:message-id:subject:from:to:content-type; bh=L63tlYLKUMGwEyJT6ceomGCrmbJBd0+572GQaVLb1xs=; b=J0cmVjTmCqkGihAMFnvbecT6UHWskj2zpqwGE7Ckpro7fIgos2akQnr/LjuvJNN67+ MsrAAu8Jss7lwQGwbliZ0W2H/NILHkl0yVhGGRJme0lsE3pwhj0yLfz7AvBpILwMJVHU b7wO5+ZIlqnCWk15+qqQWiBEEhCokhE1w7YhVJmKdTX0f0IL5VIeGcnERNm7zwnT2NW4 0BASlqWxJz6HA6bIastFewf2SmTVacLxPK1YqdCD0KGcGKeApAN/wPhscg9Nada1f+A6 /lnN25BA0z3FZAoO43QF5psIY/KSlLiu52hp09MhEN4cKInlKTfwICbtsCKWIMOpv12l iGTg==
Hi,
 ÂI am using xfs on a raid 5 (~100TB) and put log on external ssd device, the mount information is:
/dev/sdc on /data/fhgfs/fhgfs_storage type xfs (rw,relatime,attr2,delaylog,logdev=/dev/sdb1,sunit=512,swidth=15872,noquota).
 when doing only reading / only writing , the speed is very fast(~1.5G), but when do both the speed is very slow (100M), and high r_await(160) and w_await(200000).
 Â1. how can I reduce average request time?
 Â2. can I use ssd as write/read cache for xfs?

BestÂregards,
Quanjun

<Prev in Thread] Current Thread [Next in Thread>