Date: Wed, 23 Jan 2013 08:37:26 +0100 From: Oliver Lehmann <lehmann@ans-netz.de> To: fs@freebsd.org Subject: ZFS: is getting zfs slower with more data on the fs? Message-ID: <20130123083726.Horde.WFWBzChUy3RRAjdkMOnNeg7@avocado.salatschuessel.net>
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Hi,
I have for example 2 filesystems:
NAME zroot/usr zroot/usr/testfs
TYPE filesystem filesystem
CREATION Wed Sep 7 21:45 2011 Tue Jan 22 21:47 2013
USED 15.6G 31K
AVAIL 7.21G 20.0G
REFER 12.8G 31K
RATIO 1.00x 1.00x
MOUNTED yes yes
ORIGIN - -
QUOTA none none
RESERV none none
VOLSIZE - -
VOLBLOCK - -
RECSIZE 128K 128K
MOUNTPOINT legacy legacy
SHARENFS off off
CHECKSUM fletcher4 fletcher4
COMPRESS off off
ATIME off off
DEVICES on on
EXEC on on
SETUID on on
RDONLY off off
JAILED off off
SNAPDIR hidden hidden
ACLMODE discard discard
ACLINHERIT restricted restricted
CANMOUNT on on
XATTR off off
COPIES 1 1
VERSION 5 5
UTF8ONLY off off
NORMALIZATION none none
CASE sensitive sensitive
VSCAN off off
NBMAND off off
SHARESMB off off
REFQUOTA 20G 20G
REFRESERV none none
PRIMARYCACHE all all
SECONDARYCACHE all all
USEDSNAP 0 0
USEDDS 12.8G 31K
USEDCHILD 2.82G 0
USEDREFRESERV 0 0
DEFER_DESTROY - -
USERREFS - -
LOGBIAS latency latency
DEDUP off off
MLSLABEL standard standard
SYNC 1.00x 1.00x
REFRATIO 12.8G 31K
WRITTEN - -
And I wonder why I have different write performance on
each of those filesystems:
zroot/usr:
Version 1.97 ------Sequential Output------ --Sequential Input-
--Random-
Concurrency 1 -Per Chr- --Block-- -Rewrite- -Per Chr- --Block--
--Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP
/sec %CP
nudel.salatsc 6544M 18 99 48439 50 37901 47 46 99 188508 87
214.8 14
Latency 585ms 1550ms 780ms 223ms 388ms 214ms
zroot/usr/testfs:
Version 1.97 ------Sequential Output------ --Sequential Input-
--Random-
Concurrency 1 -Per Chr- --Block-- -Rewrite- -Per Chr- --Block--
--Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP
/sec %CP
nudel.salatsc 6544M 18 99 80818 91 55605 74 46 99 184481 85
225.7 15
Latency 631ms 1159ms 2156ms 199ms 361ms 239ms
root@nudel testfs> zpool status
pool: zroot
state: ONLINE
scan: scrub repaired 0 in 0h9m with 0 errors on Fri Jan 4 15:55:10 2013
config:
NAME STATE READ WRITE CKSUM
zroot ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
ada0p3 ONLINE 0 0 0
ada1p3 ONLINE 0 0 0
errors: No known data errors
root@nudel testfs>
/usr is filled with 12GB of data, /usr/testfs is empty.
Why is it like this? I'm trying to figure out how to configure a ZFS fs as
fast as possible for things like /usr/obj where I do not care about data
security that much. My "testfs" is a filesystem where I wanted to test
different things - but now it is faster without any changes?!
PS: please keep me CCed
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