Re: MySQL Performance Woody Vs Sarge

[Simon <dev@networker.co.nz>]

Jacob S wrote:

> > > What does 'hdparm' return for the RAID drive on each server when you
> > > don't give it any options (ie. 'hdparm /dev/hda')? You might also
> > > include the same output for hdparm run each of the hard drives used
> > > to make the array. 
> > >
> > > What are the specs on the hard drives/RAID setup on both servers?
> > > Are they hardware raid or software raid?
> >
> > Both software RAID 0, both use Promise 2 channel PCI cards, Hard
> > Drives  are IBM deskstar(?) 7200 40GB.

> > live: # hdparm /dev/md0
>
>   ^^^^^
>   Woody
>   faster

> > /dev/md0:
> >  readonly     =  0 (off)
> >  readahead    = 256 (on)
> >  geometry     = 25248/2/4, sectors = 80418048, start = 0

> > dev: hdparm /dev/md0
>
>   ^^^^
>   Sarge
>   slower 

> > /dev/md0:
> >  BLKROGET failed: Invalid argument
> >  geometry     = 23632/2/4, sectors = 80405120, start = 0

Jacob - Nearly Right:

woody(dev) = faster (Linux version 2.4.18-bf2.4):

# hdparm /dev/md0
/dev/md0:
 BLKROGET failed: Invalid argument
 geometry     = 23632/2/4, sectors = 80405120, start = 0

The above raid consists of:

# hdparm /dev/hde

/dev/hde:
 multcount    =  0 (off)
 I/O support  =  0 (default 16-bit)
 unmaskirq    =  0 (off)
 using_dma    =  1 (on)
 keepsettings =  0 (off)
 nowerr       =  0 (off)
 readonly     =  0 (off)
 readahead    =  8 (on)
 geometry     = 5005/255/63, sectors = 80418240, start = 0
 busstate     =  1 (on)

# hdparm /dev/hdg

/dev/hdg:
 multcount    =  0 (off)
 I/O support  =  0 (default 16-bit)
 unmaskirq    =  0 (off)
 using_dma    =  1 (on)
 keepsettings =  0 (off)
 nowerr       =  0 (off)
 readonly     =  0 (off)
 readahead    =  8 (on)
 geometry     = 79780/16/63, sectors = 80418240, start = 0
 busstate     =  1 (on)


sarge(production) = slower (Linux version 2.6.8-2-k7):

# hdparm /dev/md0
/dev/md0:
 readonly     =  0 (off)
 readahead    = 256 (on)
 geometry     = 25248/2/4, sectors = 80418048, start = 0

The above raid consists of:

# hdparm /dev/hde

/dev/hde:
 multcount    =  0 (off)
 IO_support   =  0 (default 16-bit)
 unmaskirq    =  0 (off)
 using_dma    =  1 (on)
 keepsettings =  0 (off)
 readonly     =  0 (off)
 readahead    = 256 (on)
 geometry     = 65535/16/63, sectors = 80418240, start = 0

# hdparm /dev/hdg

/dev/hdg:
 multcount    =  0 (off)
 IO_support   =  0 (default 16-bit)
 unmaskirq    =  0 (off)
 using_dma    =  1 (on)
 keepsettings =  0 (off)
 readonly     =  0 (off)
 readahead    = 256 (on)
 geometry     = 65535/16/63, sectors = 80418240, start = 0

> [Cc'ed back to the debian-user list, as I'm sure there are people that
> know more about this than I do. :-)]
>
> What is the kernel version on each server? Are they both using the same
> kernel module for the Promise controller? I'm getting the two boxes
> confused... let me know if my notes above are correct.

See above.

> The md0 devices should consist of two /dev/hd* devices. Please show
> hdparm output for them as well.

See above.

> I'm grasping at straws a little bit, as the results aren't what I first
> expected (unless I'm mixing previous facts about the servers). But maybe
> somebody else here will have some more clues.

Thanks
Simon