[CentOS] Very slow disk performance on CentOS 4.5

Ross S. W. Walker rwalker at medallion.com
Fri Aug 31 16:20:18 UTC 2007


From: centos-bounces at centos.org 
[mailto:centos-bounces at centos.org] On Behalf Of Alfred von Campe
> 
> I recently moved my CentOS 4.5 disk from a Lenovo ThinkCentre M52  
> (3.2 GHz Pentium 4) to a Lenovo ThinkCentre M55 (3.4 GHz Core 2  
> Duo).  I had to install the SMP kernel, but other than that  
> everything just worked.  I did have an issue with accidentally  
> initializing my /boot partition, but that was my own fault.
> 
> But the system was not feeling right.  Some things just seemed to be  
> slower, but I couldn't put my finger on it.  Today, I noticed that  
> disk I/O was very slow to one of the disks (the boot drive, /dev/ 
> hda).  It took over 18 minutes to unzip a set of files that used to  
> take just under 2 minutes on the old system.  Sure enough, if I  
> copied the files to the second drive (/dev/sda), I was able to unzip  
> them in under 2 minutes again.
> 
> When I accidentally clobbered the /boot partition, I learned that  
> there were two IDE controllers on this motherboard, which explained  
> why one SATA drive was named /dev/hda and the other SATA drive /dev/ 
> sda.   But I find it hard to believe that there would be such a  
> performance difference between the two controllers/drivers/disks.   
> And I know the slow disk worked just fine before I moved it to the  
> new system.
> 
> Any ideas what could cause a drive to be so slow?  Could it be that  
> DMA is disabled on the drive (see the output of hdparm 
> below)?  Also,  
> why does hdparm work for one disk but not the other?
> 
> Thanks for any pointers,
> Alfred

See if the drive supports DMA and 32-bit IO and if it does set it
with hdparm (put in the hdparm.conf to do so across reboots).

And look into getting a SATA replacement, the PATA on these boards
are really meant for DVD/CD-ROMs, etc.


> # lspci
> 00:00.0 Host bridge: Intel Corporation 82Q963/Q965 Memory Controller  
> Hub (rev 02)
> 00:01.0 PCI bridge: Intel Corporation 82Q963/Q965 PCI Express Root  
> Port (rev 02)
> 00:1a.0 USB Controller: Intel Corporation 82801H (ICH8 Family) USB  
> UHCI Contoller #4 (rev 02)
> 00:1a.1 USB Controller: Intel Corporation 82801H (ICH8 Family) USB  
> UHCI Controller #5 (rev 02)
> 00:1a.7 USB Controller: Intel Corporation 82801H (ICH8 Family) USB2  
> EHCI Controller #2 (rev 02)
> 00:1b.0 Audio device: Intel Corporation 82801H (ICH8 Family) 
> HD Audio  
> Controller (rev 02)
> 00:1c.0 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI  
> Express Port 1 (rev 02)
> 00:1c.4 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI  
> Express Port 5 (rev 02)
> 00:1d.0 USB Controller: Intel Corporation 82801H (ICH8 Family) USB  
> UHCI Controller #1 (rev 02)
> 00:1d.1 USB Controller: Intel Corporation 82801H (ICH8 Family) USB  
> UHCI Controller #2 (rev 02)
> 00:1d.2 USB Controller: Intel Corporation 82801H (ICH8 Family) USB  
> UHCI Controller #3 (rev 02)
> 00:1d.7 USB Controller: Intel Corporation 82801H (ICH8 Family) USB2  
> EHCI Controller #1 (rev 02)
> 00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev f2)
> 00:1f.0 ISA bridge: Intel Corporation 82801HB/HR (ICH8/R) LPC  
> Interface Controller (rev 02)
> 00:1f.2 IDE interface: Intel Corporation 82801H (ICH8 Family) 4 port  
> SATA IDE Controller (rev 02)
> 00:1f.3 SMBus: Intel Corporation 82801H (ICH8 Family) SMBus  
> Controller (rev 02)
> 00:1f.5 IDE interface: Intel Corporation 82801H (ICH8 Family) 2 port  
> SATA IDE Controller (rev 02)
> 01:00.0 VGA compatible controller: nVidia Corporation G70 [GeForce  
> 7300 GT] (rev a1)
> 03:00.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5755  
> Gigabit Ethernet PCI Express (rev 02)
> 0a:0a.0 Serial controller: NetMos Technology PCI 9835 Multi-I/O  
> Controller (rev 01)
> 
> 
> 00:1f.2 IDE interface: Intel Corporation 82801H (ICH8 Family) 4 port  
> SATA IDE Controller (rev 02) (prog-if 8a [Master SecP PriP])
>          Subsystem: Lenovo: Unknown device 1011
>          Flags: bus master, 66Mhz, medium devsel, latency 0, IRQ 177
>          I/O ports at <unassigned>
>          I/O ports at <unassigned>
>          I/O ports at <unassigned>
>          I/O ports at <unassigned>
>          I/O ports at 30d0 [size=16]
>          I/O ports at 30c0 [size=16]
>          Capabilities: [70] Power Management version 3
> 
> 00:1f.5 IDE interface: Intel Corporation 82801H (ICH8 Family) 2 port  
> SATA IDE Controller (rev 02) (prog-if 85 [Master SecO PriO])
>          Subsystem: Lenovo: Unknown device 1011
>          Flags: bus master, 66Mhz, medium devsel, latency 0, IRQ 185
>          I/O ports at 3428 [size=8]
>          I/O ports at 341c [size=4]
>          I/O ports at 3420 [size=8]
>          I/O ports at 3418 [size=4]
>          I/O ports at 30f0 [size=16]
>          I/O ports at 30e0 [size=16]
>          Capabilities: [70] Power Management version 3
> 
> # hdparm /dev/hda
> /dev/hda:
> multcount    = 16 (on)
> IO_support   =  0 (default 16-bit)
> unmaskirq    =  0 (off)
> using_dma    =  0 (off)
> keepsettings =  0 (off)
> readonly     =  0 (off)
> readahead    = 256 (on)
> geometry     = 24792/255/63, sectors = 203928109056, start = 0
> 
> # hdparm /dev/sda
> /dev/sda:
> HDIO_GET_MULTCOUNT failed: Inappropriate ioctl for device
> IO_support   =  0 (default 16-bit)
> readonly     =  0 (off)
> readahead    = 256 (on)
> geometry     = 9730/255/63, sectors = 80032038912, start = 0
> 
> 
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