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"liuyue" 12-27-2007 05:30 AM

ext3 peformance problem
 
ext3-usershello all,

I am testing ext3 file system recently but find some problem
I use GreatTurbo Enterprise Server 10 (Zuma) and 2.6.20 kernel
I conducted my test as follows:

mkfs.ext3 /dev/sdb1
mount /dev/sdb1 /mnt/test
cd /mnt/test
mkdir 0 1 2 3 4 5 6 7

I test write and read performance under different subdirs and give the performance result. I also use filefrag to see the file layout.

Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/0/tmpfile -c -e -+n -w
5242880 1024 72706 0 80474 0
/mnt/test/0/tmpfile: 44 extents found, perfection would be 41 extents

Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/1/tmpfile -c -e -+n -w
5242880 1024 49957 0 52899 0
/mnt/test/1/tmpfile: 42 extents found, perfection would be 41 extents

Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/2/tmpfile -c -e -+n -w
5242880 1024 60292 0 64664 0
/mnt/test/2/tmpfile: 42 extents found, perfection would be 41 extents

Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/3/tmpfile -c -e -+n -w
5242880 1024 70540 0 78644 0
/mnt/test/3/tmpfile: 46 extents found, perfection would be 41 extents

Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/4/tmpfile -c -e -+n -w
5242880 1024 61334 0 67778 0
/mnt/test/4/tmpfile: 44 extents found, perfection would be 41 extents

Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/5/tmpfile -c -e -+n -w
5242880 1024 66735 0 75114 0
/mnt/test/5/tmpfile: 42 extents found, perfection would be 41 extents

Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/6/tmpfile -c -e -+n -w
5242880 1024 65062 0 72686 0
/mnt/test/6/tmpfile: 44 extents found, perfection would be 41 extents

Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/7/tmpfile -c -e -+n -w
5242880 1024 69247 0 78563 0
/mnt/test/7/tmpfile: 45 extents found, perfection would be 41 extents

Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/tmpfile -c -e -+n -w
5242880 1024 77085 0 81696 0

Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/5/tmpfile2 -c -e -+n -w
/mnt/test/5/tmpfile2: 48 extents found, perfection would be 41 extents
5242880 1024 57776 0 64870 0

Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/5/tmpfile3 -c -e -+n -w
5242880 1024 54799 0 59145 0
/mnt/test/5/tmpfile3: 44 extents found, perfection would be 41 extents

My questions are:
1. why the performances under different subdirs varies so much? In /mnt/test/0 the performance is 72/80, while in /mnt/test/1 the performance is 49/53
2. I see that the extents of all files are nearly the same, but their performances are different. What are the other factors that influence the performance except for the extents(fragmentation) of the file?
3. Is it true that the more files there already exists in a dir, the lower performance we will get if we test under the dir?
as in my test, the performance of /mnt/test/5/tmpfile is 66/75, while the performances of /mnt/test/5/tmpfile2 and tmpfile3 are 57/64 54/59

Thanks very much



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Ext3-users@redhat.com
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"liuyue" 01-03-2008 10:20 AM

ext3 peformance problem
 
After doing some tests, I think I have found out the reasons.

The read/write performance of an hard disk is not homogenous. The beginning of the disk is stored on the further cylinders from the center, while the end of the disk is stored on the cylinders close to the center. Because the disk rotation speed is constant, and the information density is constant, the raw
performance of the disk is not the same for all cylinders. The performance degradation can be up to 50% when comparing performances at
the beginning of the disk and at the end of the disk.

I creat a small partition on the disk (using the first 2000 cylinders of the total 17000 cylinders on the disk), mount ext3 file system on it and test the performances of different directories. The performances under different directories are nearly the same :)


======= 2008-01-03 19:06:11 ζ‚¨εœ¨ζ₯δΏ‘δΈ*ε†™ι“οΌš=======

>ext3-usershello all,
>
> I am testing ext3 file system recently but find some problem
> I use GreatTurbo Enterprise Server 10 (Zuma) and 2.6.20 kernel
> I conducted my test as follows:
>
> mkfs.ext3 /dev/sdb1
> mount /dev/sdb1 /mnt/test
> cd /mnt/test
> mkdir 0 1 2 3 4 5 6 7
>
> I test write and read performance under different subdirs and give the performance result. I also use filefrag to see the file layout.
>
>Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/0/tmpfile -c -e -+n -w
> 5242880 1024 72706 0 80474 0
> /mnt/test/0/tmpfile: 44 extents found, perfection would be 41 extents
>
>Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/1/tmpfile -c -e -+n -w
> 5242880 1024 49957 0 52899 0
>/mnt/test/1/tmpfile: 42 extents found, perfection would be 41 extents
>
>Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/2/tmpfile -c -e -+n -w
> 5242880 1024 60292 0 64664 0
> /mnt/test/2/tmpfile: 42 extents found, perfection would be 41 extents
>
> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/3/tmpfile -c -e -+n -w
> 5242880 1024 70540 0 78644 0
> /mnt/test/3/tmpfile: 46 extents found, perfection would be 41 extents
>
> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/4/tmpfile -c -e -+n -w
> 5242880 1024 61334 0 67778 0
> /mnt/test/4/tmpfile: 44 extents found, perfection would be 41 extents
>
> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/5/tmpfile -c -e -+n -w
> 5242880 1024 66735 0 75114 0
> /mnt/test/5/tmpfile: 42 extents found, perfection would be 41 extents
>
> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/6/tmpfile -c -e -+n -w
> 5242880 1024 65062 0 72686 0
> /mnt/test/6/tmpfile: 44 extents found, perfection would be 41 extents
>
> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/7/tmpfile -c -e -+n -w
> 5242880 1024 69247 0 78563 0
> /mnt/test/7/tmpfile: 45 extents found, perfection would be 41 extents
>
> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/tmpfile -c -e -+n -w
> 5242880 1024 77085 0 81696 0
>
> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/5/tmpfile2 -c -e -+n -w
> /mnt/test/5/tmpfile2: 48 extents found, perfection would be 41 extents
> 5242880 1024 57776 0 64870 0
>
> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/5/tmpfile3 -c -e -+n -w
> 5242880 1024 54799 0 59145 0
> /mnt/test/5/tmpfile3: 44 extents found, perfection would be 41 extents
>
> My questions are:
>1. why the performances under different subdirs varies so much? In /mnt/test/0 the performance is 72/80, while in /mnt/test/1 the performance is 49/53
>2. I see that the extents of all files are nearly the same, but their performances are different. What are the other factors that influence the performance except for the extents(fragmentation) of the file?
>3. Is it true that the more files there already exists in a dir, the lower performance we will get if we test under the dir?
>as in my test, the performance of /mnt/test/5/tmpfile is 66/75, while the performances of /mnt/test/5/tmpfile2 and tmpfile3 are 57/64 54/59
>
>Thanks very much
>
>
>
>

= = = = = = = = = = = = = = = = = = = =


        致
瀼!


γ€€γ€€γ€€γ€€γ€€γ€€γ€€γ€€liuyue
γ€€γ€€γ€€γ€€γ€€γ€€γ€€γ€€liuyue@ncic.ac.cn
γ€€γ€€γ€€γ€€γ€€γ€€γ€€γ€€γ€€γ€€2008-01-03


_______________________________________________
Ext3-users mailing list
Ext3-users@redhat.com
https://www.redhat.com/mailman/listinfo/ext3-users

"Ling C. Ho" 01-03-2008 02:51 PM

ext3 peformance problem
 
I find the "oldalloc" option helpful when doing tests like this, even if
you are writing to a single huge directory. Files/dirs will always be
written close to each other on the disk physically starting from the
beginning of the disk.

...
ling

liuyue wrote:
> After doing some tests, I think I have found out the reasons.
>
> The read/write performance of an hard disk is not homogenous. The beginning of the disk is stored on the further cylinders from the center, while the end of the disk is stored on the cylinders close to the center. Because the disk rotation speed is constant, and the information density is constant, the raw
> performance of the disk is not the same for all cylinders. The performance degradation can be up to 50% when comparing performances at
> the beginning of the disk and at the end of the disk.
>
> I creat a small partition on the disk (using the first 2000 cylinders of the total 17000 cylinders on the disk), mount ext3 file system on it and test the performances of different directories. The performances under different directories are nearly the same :)
>
>
> ======= 2008-01-03 19:06:11 ζ‚¨εœ¨ζ₯δΏ‘δΈ*ε†™ι“οΌš=======
>
>
>> ext3-usershello all,
>>
>> I am testing ext3 file system recently but find some problem
>> I use GreatTurbo Enterprise Server 10 (Zuma) and 2.6.20 kernel
>> I conducted my test as follows:
>>
>> mkfs.ext3 /dev/sdb1
>> mount /dev/sdb1 /mnt/test
>> cd /mnt/test
>> mkdir 0 1 2 3 4 5 6 7
>>
>> I test write and read performance under different subdirs and give the performance result. I also use filefrag to see the file layout.
>>
>> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/0/tmpfile -c -e -+n -w
>> 5242880 1024 72706 0 80474 0
>> /mnt/test/0/tmpfile: 44 extents found, perfection would be 41 extents
>>
>> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/1/tmpfile -c -e -+n -w
>> 5242880 1024 49957 0 52899 0
>> /mnt/test/1/tmpfile: 42 extents found, perfection would be 41 extents
>>
>> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/2/tmpfile -c -e -+n -w
>> 5242880 1024 60292 0 64664 0
>> /mnt/test/2/tmpfile: 42 extents found, perfection would be 41 extents
>>
>> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/3/tmpfile -c -e -+n -w
>> 5242880 1024 70540 0 78644 0
>> /mnt/test/3/tmpfile: 46 extents found, perfection would be 41 extents
>>
>> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/4/tmpfile -c -e -+n -w
>> 5242880 1024 61334 0 67778 0
>> /mnt/test/4/tmpfile: 44 extents found, perfection would be 41 extents
>>
>> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/5/tmpfile -c -e -+n -w
>> 5242880 1024 66735 0 75114 0
>> /mnt/test/5/tmpfile: 42 extents found, perfection would be 41 extents
>>
>> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/6/tmpfile -c -e -+n -w
>> 5242880 1024 65062 0 72686 0
>> /mnt/test/6/tmpfile: 44 extents found, perfection would be 41 extents
>>
>> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/7/tmpfile -c -e -+n -w
>> 5242880 1024 69247 0 78563 0
>> /mnt/test/7/tmpfile: 45 extents found, perfection would be 41 extents
>>
>> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/tmpfile -c -e -+n -w
>> 5242880 1024 77085 0 81696 0
>>
>> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/5/tmpfile2 -c -e -+n -w
>> /mnt/test/5/tmpfile2: 48 extents found, perfection would be 41 extents
>> 5242880 1024 57776 0 64870 0
>>
>> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/5/tmpfile3 -c -e -+n -w
>> 5242880 1024 54799 0 59145 0
>> /mnt/test/5/tmpfile3: 44 extents found, perfection would be 41 extents
>>
>> My questions are:
>> 1. why the performances under different subdirs varies so much? In /mnt/test/0 the performance is 72/80, while in /mnt/test/1 the performance is 49/53
>> 2. I see that the extents of all files are nearly the same, but their performances are different. What are the other factors that influence the performance except for the extents(fragmentation) of the file?
>> 3. Is it true that the more files there already exists in a dir, the lower performance we will get if we test under the dir?
>> as in my test, the performance of /mnt/test/5/tmpfile is 66/75, while the performances of /mnt/test/5/tmpfile2 and tmpfile3 are 57/64 54/59
>>
>> Thanks very much
>>
>>
>>
>>
>>
>
> = = = = = = = = = = = = = = = = = = = =
>
>
>         致
> 瀼!
>
>
> γ€€γ€€γ€€γ€€γ€€γ€€γ€€γ€€liuyue
> γ€€γ€€γ€€γ€€γ€€γ€€γ€€γ€€liuyue@ncic.ac.cn
> γ€€γ€€γ€€γ€€γ€€γ€€γ€€γ€€γ€€γ€€2008-01-03
>
>
> _______________________________________________
> Ext3-users mailing list
> Ext3-users@redhat.com
> https://www.redhat.com/mailman/listinfo/ext3-users
>
>



_______________________________________________
Ext3-users mailing list
Ext3-users@redhat.com
https://www.redhat.com/mailman/listinfo/ext3-users

"liuyue" 01-07-2008 01:55 AM

ext3 peformance problem
 
It does help !!

======= 2008-01-03 23:51:07 ζ‚¨εœ¨ζ₯δΏ‘δΈ*ε†™ι“οΌš=======

>I find the "oldalloc" option helpful when doing tests like this, even if
>you are writing to a single huge directory. Files/dirs will always be
>written close to each other on the disk physically starting from the
>beginning of the disk.
>
>...
>ling
>
>liuyue wrote:
>> After doing some tests, I think I have found out the reasons.
>>
>> The read/write performance of an hard disk is not homogenous. The beginning of the disk is stored on the further cylinders from the center, while the end of the disk is stored on the cylinders close to the center. Because the disk rotation speed is constant, and the information density is constant, the raw
>> performance of the disk is not the same for all cylinders. The performance degradation can be up to 50% when comparing performances at
>> the beginning of the disk and at the end of the disk.
>>
>> I creat a small partition on the disk (using the first 2000 cylinders of the total 17000 cylinders on the disk), mount ext3 file system on it and test the performances of different directories. The performances under different directories are nearly the same :)
>>
>>
>> ======= 2008-01-03 19:06:11 ζ‚¨εœ¨ζ₯δΏ‘δΈ*ε†™ι“οΌš=======
>>
>>
>>> ext3-usershello all,
>>>
>>> I am testing ext3 file system recently but find some problem
>>> I use GreatTurbo Enterprise Server 10 (Zuma) and 2.6.20 kernel
>>> I conducted my test as follows:
>>>
>>> mkfs.ext3 /dev/sdb1
>>> mount /dev/sdb1 /mnt/test
>>> cd /mnt/test
>>> mkdir 0 1 2 3 4 5 6 7
>>>
>>> I test write and read performance under different subdirs and give the performance result. I also use filefrag to see the file layout.
>>>
>>> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/0/tmpfile -c -e -+n -w
>>> 5242880 1024 72706 0 80474 0
>>> /mnt/test/0/tmpfile: 44 extents found, perfection would be 41 extents
>>>
>>> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/1/tmpfile -c -e -+n -w
>>> 5242880 1024 49957 0 52899 0
>>> /mnt/test/1/tmpfile: 42 extents found, perfection would be 41 extents
>>>
>>> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/2/tmpfile -c -e -+n -w
>>> 5242880 1024 60292 0 64664 0
>>> /mnt/test/2/tmpfile: 42 extents found, perfection would be 41 extents
>>>
>>> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/3/tmpfile -c -e -+n -w
>>> 5242880 1024 70540 0 78644 0
>>> /mnt/test/3/tmpfile: 46 extents found, perfection would be 41 extents
>>>
>>> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/4/tmpfile -c -e -+n -w
>>> 5242880 1024 61334 0 67778 0
>>> /mnt/test/4/tmpfile: 44 extents found, perfection would be 41 extents
>>>
>>> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/5/tmpfile -c -e -+n -w
>>> 5242880 1024 66735 0 75114 0
>>> /mnt/test/5/tmpfile: 42 extents found, perfection would be 41 extents
>>>
>>> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/6/tmpfile -c -e -+n -w
>>> 5242880 1024 65062 0 72686 0
>>> /mnt/test/6/tmpfile: 44 extents found, perfection would be 41 extents
>>>
>>> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/7/tmpfile -c -e -+n -w
>>> 5242880 1024 69247 0 78563 0
>>> /mnt/test/7/tmpfile: 45 extents found, perfection would be 41 extents
>>>
>>> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/tmpfile -c -e -+n -w
>>> 5242880 1024 77085 0 81696 0
>>>
>>> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/5/tmpfile2 -c -e -+n -w
>>> /mnt/test/5/tmpfile2: 48 extents found, perfection would be 41 extents
>>> 5242880 1024 57776 0 64870 0
>>>
>>> Command line used: /root/iozone -s 5g -r 1m -i 0 -i 1 -f /mnt/test/5/tmpfile3 -c -e -+n -w
>>> 5242880 1024 54799 0 59145 0
>>> /mnt/test/5/tmpfile3: 44 extents found, perfection would be 41 extents
>>>
>>> My questions are:
>>> 1. why the performances under different subdirs varies so much? In /mnt/test/0 the performance is 72/80, while in /mnt/test/1 the performance is 49/53
>>> 2. I see that the extents of all files are nearly the same, but their performances are different. What are the other factors that influence the performance except for the extents(fragmentation) of the file?
>>> 3. Is it true that the more files there already exists in a dir, the lower performance we will get if we test under the dir?
>>> as in my test, the performance of /mnt/test/5/tmpfile is 66/75, while the performances of /mnt/test/5/tmpfile2 and tmpfile3 are 57/64 54/59
>>>
>>> Thanks very much
>>>
>>>
>>>
>>>
>>>
>>
>> = = = = = = = = = = = = = = = = = = = =
>>
>>
>>         致
>> 瀼!
>>
>>
>> γ€€γ€€γ€€γ€€γ€€γ€€γ€€γ€€liuyue
>> γ€€γ€€γ€€γ€€γ€€γ€€γ€€γ€€liuyue@ncic.ac.cn
>> γ€€γ€€γ€€γ€€γ€€γ€€γ€€γ€€γ€€γ€€2008-01-03
>>
>>
>> _______________________________________________
>> Ext3-users mailing list
>> Ext3-users@redhat.com
>> https://www.redhat.com/mailman/listinfo/ext3-users
>>
>>

= = = = = = = = = = = = = = = = = = = =


        致
瀼!


γ€€γ€€γ€€γ€€γ€€γ€€γ€€γ€€liuyue
γ€€γ€€γ€€γ€€γ€€γ€€γ€€γ€€liuyue@ncic.ac.cn
γ€€γ€€γ€€γ€€γ€€γ€€γ€€γ€€γ€€γ€€2008-01-07


_______________________________________________
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https://www.redhat.com/mailman/listinfo/ext3-users


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