slow after upgrade to CentOS 5 (RHEL5)

DISCUSSION Anthony Ewell 1 participant 1 message Nov 18, 2007 SCSI

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Anthony Ewell

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2007-11-18 23:38 UTC #0 lore raw

Quoted 43 lines

Quoted 4 lines · James Bottomley
Please don't drop the cc lists. There are others who probably have more informed opinions than I do who won't get to comment if they don't see it.
Quoted 11 lines
Quoted 10 lines · Anthony Ewell
Quoted 9 lines · James Bottomley
Quoted 8 lines · Anthony Ewell
Quoted 7 lines · James Bottomley
Quoted 6 lines · Anthony Ewell
Hi All,
If you all would not mind a post from the general
public Linux user, after doing a complete disk wipe of CentOS 4 and installing CentOS5, my system is preceived to be 3 times slower.
Did some test from my install CD/DVD's in "rescue mode" on Computer C. I used the same backup script (dump) that I use in normal boot mode. I stopped the backup after dump gave the first estimate of time:
"dump" CentOS5 install DVD in rescue mode:
transfer rate 4422 KB/s, estimated finish 4:10
"dump" CentOS4.4 (2.6.9-42.EL) install CD in rescue mode:
transfer rate 8468 KB/s, estimated finish 2:09
I also got a "dmesg" from computer B, as requested by Sumant. Computer B: VXA-3, CentOS 4.5 , SATA-150-4
-T
Hi All,
I also tested using the System Rescue CD from
http://www.sysresccd.org.
I used the same backup script (dump) that I use in normal boot mode. I stopped the backup after dump gave the first estimate of time:

Quoted 8 lines

"dump" System Rescue CD (Kernel 2.6.22.9):
transfer rate 4370 KB/s, estimated finish 4:15
So, I would say, the problem is not confined to CentOS 5, but goes all the way up to the 2.6.22.9 kernel. I hope this is a good clue.
-T

Hi All,

I ran a "bonnie++" on both Computer B and computer C.
I am not seeing any massive differences between the two that would account for the massive slowdown between Cent OS 4.4 (2.6.9-42.EL) and Cent OS 5 (2.6.18-8.1.15.el5).

Anyone have any suggestions as to how to track this down?

Many thanks,
-T

Comparison of Computer B and Computer C with "bonnie++":

Computer B (CentOS4):
------Sequential Output------ --Sequential Input- --Random-

                    -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
server.foo.lo 4G 31384 70 46283 16 21902 8 40179 82 49199 9 196.8 0

                    ------Sequential Create------ --------Random 
Create--------
                    -Create-- --Read--- -Delete-- -Create-- --Read--- 
-Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP 
/sec %CP
                 16 23106  71 +++++ +++ +++++ +++ +++++ +++ +++++ +++

+++++ +++ server.foo.local,4G,31384,70,46283,16,21902,8,40179,82,49199,9,196.8,0,16,23106,71,+++++,+++,+++++,+++,+++++,+++,+++++,+++,+++++,+++

Computer C (CentOS5):
------Sequential Output------ --Sequential Input- --Random-

                    -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
rn1.foo. 4G 32240 68 40951 9 24177 5 46265 86 71005 9 179.5 0

                    ------Sequential Create------ --------Random 
Create--------
                    -Create-- --Read--- -Delete-- -Create-- --Read--- 
-Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP 
/sec %CP
                 16 +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++

+++++ +++ rn1.rent-a-nerd.local,4G,32240,68,40951,9,24177,5,46265,86,71005,9,179.5,0,16,++ +++,+++,+++++,+++,+++++,+++,+++++,+++,+++++,+++,+++++,+++