Date: Mon, 10 Aug 2015 11:12:52 -0400 From: Julio Merino <jmmv@freebsd.org> To: freebsd-questions@freebsd.org Subject: Poor I/O performance; maybe ZFS? Message-ID: <B94A0CB6-FEDA-41AA-A335-14988E5662CC@freebsd.org>
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Hello,
I have a PowerMac G5 running 11.0-CURRENT (upgraded yesterday). The =
machine is a dual-CPU 2GHz G5 with 6GB of RAM and two drives:
ada0 at ata2 bus 0 scbus2 target 0 lun 0cd0 at ata0 bus 0 scbus0 target =
0 lun 0
ada0: <ST3160023AS 3.05> ATA-6 SATA 1.x device
ada0: Serial Number 3JS478VL
ada0: 150.000MB/s transfers (SATA 1.x, UDMA5, PIO 8192bytes)
ada0: 152627MB (312581808 512 byte sectors: 16H 63S/T 16383C)
ada1 at ata3 bus 0 scbus3 target 0 lun 0
ada1: <WDC WD6400AAKS-75A7B0 01.03B01> ATA8-ACS SATA 2.x device
ada1: Serial Number WD-WMASY2696897
ada1: 150.000MB/s transfers (SATA 1.x, UDMA5, PIO 8192bytes)
ada1: 610480MB (1250263728 512 byte sectors: 16H 63S/T 16383C)
I have a UFS file system on ada0s4 for / and a ZFS pool on ada1s2 with =
file systems for /home and poudriere.
For a while, I have felt that the system is incredibly sluggish. For =
example, a simple "make buildworld" with up-to-date obj, which should be =
I/O bound, takes forever (something like 20-30 minutes). This is =
running with src and obj on ZFS. "svn update" is similarly =
infuriatingly slow.
Today, I decided to install bonnie and ran a couple of tests using "-s =
4096".
-------Sequential Output-------- ---Sequential Input-- =
--Random--
-Per Char- --Block--- -Rewrite-- -Per Char- --Block--- =
--Seeks---
Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU =
/sec %CPU
ada0 4196 43973 62.4 46207 37.7 43259 41.9 89210 96.8 280589 95.9 =
17038.2 103.1
tank 4196 54093 72.2 27596 93.0 21478 90.7 64214 83.5 65358 50.8 =
126.7 3.7
Note the vast difference on the numbers, especially random seeks.
In case this matters, this is how ada1s2 looks like:
1. Name: ada1s2
Mediasize: 640135019520 (596G)
Sectorsize: 512
Stripesize: 0
Stripeoffset: 9216
Mode: r1w1e1
rawtype: FreeBSD-ZFS
label: 1
length: 640135019520
offset: 9216
type: freebsd-zfs
index: 1
end: 1250263727
start: 18
Any obvious things I should look at?
Thank you!=
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