Re: Oracle RAC on OL 6.1

From: Mladen Gogala <gogala.mladen_at_gmail.com>
Date: Wed, 23 Nov 2011 17:16:24 +0000 (UTC)
Message-ID: <pan.2011.11.23.17.16.24_at_gmail.com>



On Wed, 23 Nov 2011 00:47:43 -0800, mhoys wrote:
> "Technology Preview features"... So, does this mean that they removed
> support for XFS between versions 6.0 and 6.1???
> 
> Matthias Hoys

Well, for the normal file operations, especially with small files, Ext4 is quite a bit faster. I've even performed a little benchmark to that end. Unfortunately, a lot of what I am doing are not "normal file operations". Virtual machines operate on virtual disks which are typically 20GB or even more. Databases also have large files which tend to be accessed using direct I/O. In both cases the ability to defragment files can lead to palpable performance gains. I don't know about the "untested" part. XFS was created and put into the open source by SGI, quite a bit before Ext4 was even conceived. XFS is definitely older and more mature of the two. Here is a little benchmark that shows the difference. My /home file system is XFS while the / file system is Ext4. Here is a little something that illustrates the relative speeds:

/home partition (XFS):


[mgogala_at_medo Downloads]$ time dd if=oel-6.1.iso of=/dev/null
5902464+0 records in
5902464+0 records out
3022061568 bytes (3.0 GB) copied, 32.1617 s, 94.0 MB/s

real	0m32.206s
user	0m2.869s
sys	0m19.141s

[mgogala_at_medo Downloads]$ time dd if=oel-6.1.iso of=/dev/null bs=64k
46113+0 records in
46113+0 records out
3022061568 bytes (3.0 GB) copied, 31.8788 s, 94.8 MB/s
real	0m31.949s
user	0m0.048s
sys	0m8.055s

[mgogala_at_medo Downloads]$ time dd if=oel-6.1.iso of=/dev/null bs=128k
23056+1 records in
23056+1 records out
3022061568 bytes (3.0 GB) copied, 34.0289 s, 88.8 MB/s
real	0m34.483s
user	0m0.051s
sys	0m8.358s

[mgogala_at_medo Downloads]$ time dd if=oel-6.1.iso of=/dev/null bs=1024k
2882+1 records in
2882+1 records out
3022061568 bytes (3.0 GB) copied, 32.2709 s, 93.6 MB/s
real	0m32.337s
user	0m0.026s
sys	0m9.393s

[mgogala_at_medo Downloads]$

/tmp (Ext4):


[mgogala_at_medo tmp]$ time dd if=oel-6.1.iso of=/dev/null
5902464+0 records in
5902464+0 records out
3022061568 bytes (3.0 GB) copied, 28.6371 s, 106 MB/s

real	0m28.675s
user	0m2.270s
sys	0m14.997s

[mgogala_at_medo tmp]$ time dd if=oel-6.1.iso of=/dev/null bs=64k
46113+0 records in
46113+0 records out
3022061568 bytes (3.0 GB) copied, 29.0088 s, 104 MB/s
real	0m29.067s
user	0m0.084s
sys	0m10.453s

[mgogala_at_medo tmp]$ time dd if=oel-6.1.iso of=/dev/null bs=128k
23056+1 records in
23056+1 records out
3022061568 bytes (3.0 GB) copied, 27.0044 s, 112 MB/s
real	0m27.065s
user	0m0.054s
sys	0m10.663s

[mgogala_at_medo tmp]$ time dd if=oel-6.1.iso of=/dev/null bs=1024k
2882+1 records in
2882+1 records out
3022061568 bytes (3.0 GB) copied, 26.5206 s, 114 MB/s
real	0m26.580s
user	0m0.017s
sys	0m11.921s

[mgogala_at_medo tmp]$

Here is the reason why I selected XFS despite that:

[mgogala_at_medo tmp]$ filefrag /tmp/oel-6.1.iso
/tmp/oel-6.1.iso: 28 extents found
[mgogala_at_medo tmp]$ filefrag ~/Downloads/oel-6.1.iso
/home/mgogala/Downloads/oel-6.1.iso: 1 extent found

-- 
http://mgogala.byethost5.com
Received on Wed Nov 23 2011 - 11:16:24 CST

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