IDE -- mount partitions for better performance
Mehmet Erol Sanliturk
m.e.sanliturk at gmail.com
Tue Mar 15 20:21:05 UTC 2011
On Tue, Mar 15, 2011 at 3:17 PM, <freebsd_user at guice.ath.cx> wrote:
> Annotated below ...
> > Hi,
> > On Tuesday 15 March 2011 07:00:30 freebsd_user at guice.ath.cx wrote:
> >> freebsd-questions at freebsd.org
> >> Guidance with the following:
> >> We are limited to Support for ATA-100/66/33 IDE and ATAPI compliant
> >> devices. With that said, we have our atapi/33 optical on a add in
> >> controller (PCI) and are seeking to place four HDD’s on the main boards
> >> controllers. Our dilemma is where to place /, /tmp, /usr and /var from
> >> a
> >> performance standpoint. We understand that /var does quite a bit of
> >> writing and probably should go on the master hdd, but what about the
> >> /usr,
> >> /tmp and root? Hell, I’m not sure my thinking is sane as to where I
> >> ‘think’ /var should be placed/mounted.
> > did I get it right? You have four hard disks?
> Yes, four separate HDD's
> > If so, place /, /var /tmp on indiidual drives. Make the fourth disk usr
> > and mount the remaining space of the other three disks inside /usr/home.
> Are you suggesting something similar to:
> /dev/ad4s1a for /
> /dev/ad4s2a for /tmp
> /dev/ad4s3a for /usr
> /dev/ad4s4a for /var
> If so, my initial can current concern is which device (hdd) from the above
> list/configuration, should be connected to which cable connector (master
> or slave)? --depending on how much writing to a particular device is
> taking place; for instance during a 'build world' or while building
> anything from src. there is quite a bit of writing going on. I would
> think that making the disk/slice that is being written to a slave would
> decrease performance when the master to that slave is also being written
> to simultaneously. In such a case the slave would need to wait until the
> master is done writing before the slave would be able to write; Is my
> thinking on this sane?
> Please enlighten me/us.
> Thank you.
> > Locate then stuff on the other three disks which you expect to be used in
> > parallel with the /usr disk.
> I'm lost on the above suggestion; not understanding this.
> > Of course, you can mount it anywhere else if you want.
> > Erich
When four IDE hard disks are usable , then there should be at least two IDE
connectors on the main board .
IDE cables have two connectors ( connectors near to each other ) . The outer
connector is for MASTER ,
the INNER connector is for SLAVE .
IDE hard disks have JUMPERS to set the MASTER and SLAVE hard disks , and it
is very likely that on the hard disk , information about jumper settings are
printed . When there is no such information printed , it is possible that it
is printed in its manual , or it may be available from its producer web site
MASTER hard disk should be connected to outer connector , SLAVE hard disk
should be connected to INNER
Then , the computer will identify these hard disks with respect to connector
on the main board , and MASTER and SLAVE settings of the hard disks .
Then , it will list them as /dev/ad1... , /dev/ad2... , /dev/ad3... ,
/dev/ad4... , or other ad(Numbers) depending on mother board IDE ports
settings ( there may be add-on IDE cards ) , or installer may label them
If the hard disks are different from each other , it is easy to identify
which disk is detected as which device .
( Installer will list information about their sizes ( and , perhaps trade
marks ) . )
Assume that all of the hard disks are the same .
Then , it is very likely that the connector slot 0 will be detected first ,
and the connector slot 1 will be detected as second .
To be exactly sure , the following steps may be applied .
( Absolutely power down the computer for hardware modifications ) :
( Record detected connected device names . )
( On the mother board , slot numbers or letters may be printed explicitly .
Disconnect connector in IDE slot 1 and detect disks in connector in IDE slot
Then , disconnect connector in IDE slot 0 and connect IDE slot 1 connector
and detect disks in IDE slot 1.
Then , connect connector in IDE slot 0 and detect all of the disks .
After obtaining exact device names of the hard disks , final installation
may be performed .
Thank you very much .
Mehmet Erol Sanliturk
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