Re: slow after upgrade to CentOS 5 (RHEL5)

[Anthony Ewell <amewell@verizon.net>]

> James Bottomley wrote:
>> 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.
>>
>> On Sun, 2007-10-28 at 17:36 -0700, Anthony Ewell wrote:
>>> James Bottomley wrote:
>>>> On Sat, 2007-10-27 at 13:21 -0700, Anthony Ewell wrote:
>>>>> James Bottomley wrote:
>>>>>> On Wed, 2007-10-24 at 18:04 -0700, Anthony Ewell wrote:
>>>>>>> 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:
> 
>    "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,++
+++,+++,+++++,+++,+++++,+++,+++++,+++,+++++,+++,+++++,+++