From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id nATEfsfS076413 for ; Sun, 29 Nov 2009 08:41:54 -0600 Received: from BLADE3.ISTI.CNR.IT (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 04241BD4F8 for ; Sun, 29 Nov 2009 06:42:21 -0800 (PST) Received: from BLADE3.ISTI.CNR.IT (blade3.isti.cnr.it [194.119.192.19]) by cuda.sgi.com with ESMTP id 78BkkqprCDFkvxDX for ; Sun, 29 Nov 2009 06:42:21 -0800 (PST) Received: from conversionlocal.isti.cnr.it by mx.isti.cnr.it (PMDF V6.4 #31773) id <01NGO4PBRIB490OL9W@mx.isti.cnr.it> for xfs@oss.sgi.com; Sun, 29 Nov 2009 15:41:17 +0100 Date: Sun, 29 Nov 2009 15:41:31 +0100 From: Asdo Subject: Re: XFS & LVM: unexpected cp when issuing mv In-reply-to: <200911291452.20646@zmi.at> Message-id: <4B12881B.6080302@shiftmail.org> MIME-version: 1.0 References: <200911291452.20646@zmi.at> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: multipart/mixed; boundary="===============8165442846270854053==" Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Michael Monnerie Cc: xfs@oss.sgi.com This is a multi-part message in MIME format. --===============8165442846270854053== Content-type: multipart/alternative; boundary="Boundary_(ID_k1E3RIcxtx1ZPGyuZzZ/Rg)" This is a multi-part message in MIME format. --Boundary_(ID_k1E3RIcxtx1ZPGyuZzZ/Rg) Content-type: text/plain; charset=UTF-8; format=flowed Content-transfer-encoding: 7BIT Please paste the output of the following 2 commands: df /disks/sharestore/upload/ df /disks/sharestore/download/ Michael Monnerie wrote: > I have an unexpected behaviour and I hope someone can explain me the > reasons: > > This is an openSUSE 11.2 virtual machine within XENserver. XENserver can > only create 2TB disks, but I needed more. So I create 2x 2TB disks for > that VM. These disks have no partitions, but are straight LVM: > # pvscan > PV /dev/xvdb VG sharestore lvm2 [1,95 TB / 0 free] > PV /dev/xvdc VG sharestore lvm2 [1,95 TB / 0 free] > Total: 2 [3,91 TB] / in use: 2 [3,91 TB] / in no VG: 0 [0 ] > > I created one VG, and then one LV: > # vgscan > Reading all physical volumes. This may take a while... > Found volume group "sharestore" using metadata type lvm2 > # lvscan > ACTIVE '/dev/sharestore/public' [3,91 TB] inherit > > On that LV, I created an XFS filesystem, mounted from /etc/fstab: > /dev/sharestore/public /disks/sharestore xfs > noatime,nodiratime,logbufs=8,logbsize=256k,attr2,nobarrier,largeio,swalloc,inode64,prjquota > > Now when I move from one dir to another, example > mv /disks/sharestore/upload/* /disks/sharestore/download/ > > within some dirs it's a simple mv where only metadata is moved, but with > some dirs it's a physical cp+rm of the files. You can easily see that by > the speed of the mv, plus with iostat: > Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq- > sz avgqu-sz await svctm %util > xvdb 0,00 0,00 0,00 647,31 0,00 28424,75 > 87,82 18,46 29,71 0,24 15,65 > xvdc 0,00 0,40 631,14 2,40 26928,54 76,65 > 85,25 5,56 8,69 1,56 98,84 > > Until now I believed that a mv within one filesystem is always just a > metadata mv. But it seems I found a case now where even within the same > filesystem a physical cp+rm is done. Can someone explain me > > 1) why this happens > 2) how I can prevent this? > > We have files >5G there, often 20G or more, so a mv should just be a > metadata mv, everything else is inacceptable. > Could it be the way I created the VG + LV, that there's a cp instead mv? > How could I create all that to get a normal behaviour? > > Maybe like this?: > 1) create VG only on one disk > 2) create LV on that disk > 3) create XFS > 4) extend VG to 2nd disk > 5) extend LV to 2nd disk > 6) xfs_growfs to 2nd disk > > mfg zmi > > ------------------------------------------------------------------------ > > _______________________________________________ > xfs mailing list > xfs@oss.sgi.com > http://oss.sgi.com/mailman/listinfo/xfs > --Boundary_(ID_k1E3RIcxtx1ZPGyuZzZ/Rg) Content-type: text/html; charset=UTF-8 Content-transfer-encoding: 8BIT Please paste the output of the following 2 commands:

df  /disks/sharestore/upload/

df  /disks/sharestore/download/


Michael Monnerie wrote: 
I have an unexpected behaviour and I hope someone can explain me the 
reasons:

This is an openSUSE 11.2 virtual machine within XENserver. XENserver can 
only create 2TB disks, but I needed more. So I create 2x 2TB disks for 
that VM. These disks have no partitions, but are straight LVM:
# pvscan
  PV /dev/xvdb   VG sharestore   lvm2 [1,95 TB / 0    free]
  PV /dev/xvdc   VG sharestore   lvm2 [1,95 TB / 0    free]
  Total: 2 [3,91 TB] / in use: 2 [3,91 TB] / in no VG: 0 [0   ]

I created one VG, and then one LV:
# vgscan
  Reading all physical volumes.  This may take a while...
  Found volume group "sharestore" using metadata type lvm2
# lvscan
  ACTIVE            '/dev/sharestore/public' [3,91 TB] inherit

On that LV, I created an XFS filesystem, mounted from /etc/fstab:
/dev/sharestore/public /disks/sharestore  xfs        
noatime,nodiratime,logbufs=8,logbsize=256k,attr2,nobarrier,largeio,swalloc,inode64,prjquota

Now when I move from one dir to another, example
mv /disks/sharestore/upload/* /disks/sharestore/download/

within some dirs it's a simple mv where only metadata is moved, but with 
some dirs it's a physical cp+rm of the files. You can easily see that by 
the speed of the mv, plus with iostat:
Device:         rrqm/s   wrqm/s     r/s     w/s    rkB/s    wkB/s avgrq-
sz avgqu-sz   await  svctm  %util
xvdb              0,00     0,00    0,00  647,31     0,00 28424,75    
87,82    18,46   29,71   0,24  15,65
xvdc              0,00     0,40  631,14    2,40 26928,54    76,65    
85,25     5,56    8,69   1,56  98,84

Until now I believed that a mv within one filesystem is always just a 
metadata mv. But it seems I found a case now where even within the same 
filesystem a physical cp+rm is done. Can someone explain me

1) why this happens
2) how I can prevent this?

We have files >5G there, often 20G or more, so a mv should just be a 
metadata mv, everything else is inacceptable.
Could it be the way I created the VG + LV, that there's a cp instead mv?
How could I create all that to get a normal behaviour?

Maybe like this?:
1) create VG only on one disk
2) create LV on that disk
3) create XFS
4) extend VG to 2nd disk
5) extend LV to 2nd disk
6) xfs_growfs to 2nd disk

mfg zmi
  

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