LDP
/
old-www
1
1
Fork 0
Code Issues Pull Requests Releases Wiki Activity
old-www/LDP/solrhe/Securing-Optimizing-Linux-R.../chap6sec74.html

436 lines
8.2 KiB
HTML
Raw Permalink Blame History

<HTML
><HEAD
><TITLE
>Tuning IDE Hard Disk Performance</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.60"><LINK
REL="HOME"
TITLE="Securing and Optimizing Linux"
HREF="index.html"><LINK
REL="UP"
TITLE="Linux General Optimization"
HREF="gen-optim.html"><LINK
REL="PREVIOUS"
TITLE="The atime and noatime attribute"
HREF="chap6sec73.html"><LINK
REL="NEXT"
TITLE="Better manage your TCP/IP resources"
HREF="chap6sec75.html"></HEAD
><BODY
CLASS="section"
BGCOLOR="#FFFFFF"
TEXT="#000000"
LINK="#0000FF"
VLINK="#840084"
ALINK="#0000FF"
><DIV
CLASS="NAVHEADER"
><TABLE
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="3"
ALIGN="center"
>Securing and Optimizing Linux: RedHat Edition -A Hands on Guide</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="bottom"
><A
HREF="chap6sec73.html"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
>Chapter 6. Linux General Optimization</TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="chap6sec75.html"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="section"
><H1
CLASS="section"
><A
NAME="AEN4832"
>6.12. Tuning <SPAN
CLASS="acronym"
>IDE</SPAN
> Hard Disk Performance</A
></H1
><P
>&#13; Putting your swap partitions near the beginning of your drive, see <A
HREF="chap3sec14.html#pr1ch25lk1"
>This chart to get a better idea,</A
> may give you some acceptable improvement. The beginning of the drive is physically located on the outer portion of the
cylinder, and the read/write head can cover much more ground per revolution. We typically see partitions placed at the end of the drive work 3MB/s slower using the <TT
CLASS="userinput"
><B
>hdparm -t</B
></TT
> command.
</P
><P
>&#13; Performance increases have been reported on massive disk I/O operations by setting the <SPAN
CLASS="acronym"
><SPAN
CLASS="acronym"
>IDE</SPAN
></SPAN
> drivers to use DMA, 32-bit transfers and multiple sector modes. The kernel seems to use more conservative settings
unless told otherwise. The magic command to change the setting of your drive is <B
CLASS="command"
>hdparm</B
>.
To enable 32-bit I/O over the <SPAN
CLASS="acronym"
>PCI</SPAN
> buses, use the command:
<TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="screen"
>&#13; [root@deep] /#<B
CLASS="command"
> /sbin/hdparm</B
> -c1 /dev/hda <EM
>or hdb, hdc etc</EM
>.
</PRE
></TD
></TR
></TABLE
>
This will usually, depending on your <SPAN
CLASS="acronym"
>IDE</SPAN
> Disk Drive model, cut the timing buffered disk reads time by 2. The <SPAN
CLASS="citerefentry"
><SPAN
CLASS="refentrytitle"
>hdparm</SPAN
>(8)</SPAN
> manpage says that you may need to use -c 3 for some chipsets. All (E)<SPAN
CLASS="acronym"
>IDE</SPAN
>
drives still have only a 16-bit connection over the ribbon cable from the interface card.
To enable <SPAN
CLASS="acronym"
>DMA</SPAN
>, use the command:
<TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="screen"
>&#13; [root@deep] /#<B
CLASS="command"
> /sbin/hdparm</B
> -d1 /dev/hda <EM
>or hdb, hdc etc</EM
>.
</PRE
></TD
></TR
></TABLE
>
This may depend on support for your motherboard chipset being compiled into your kernel. Also, this command will enable <SPAN
CLASS="acronym"
>DMA</SPAN
> support for your hard drive, it will cut the timing buffered disk reads time and
will improve the performance by 2.
To enable multiword <SPAN
CLASS="acronym"
>DMA</SPAN
> mode 2 transfers, use the command:
<TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="screen"
>&#13; [root@deep] /#<B
CLASS="command"
>/sbin/hdparm</B
> -d1 -X34 /dev/hda <EM
>or hdb, hdc etc</EM
>.
</PRE
></TD
></TR
></TABLE
>
This sets the <SPAN
CLASS="acronym"
><SPAN
CLASS="acronym"
>IDE</SPAN
></SPAN
> transfer mode for newer <SPAN
CLASS="acronym"
>(E)<SPAN
CLASS="acronym"
>IDE</SPAN
>/ATA2</SPAN
> drives. check your hardware manual to see if you have it.
To enable Ultra<SPAN
CLASS="acronym"
>DMA</SPAN
> mode2 transfers, use the command:
<TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="screen"
>&#13; [root@deep] /#<B
CLASS="command"
> /sbin/hdparm</B
> -d1 -X66 /dev/hda <EM
>or hdb, hdc etc</EM
>.
</PRE
></TD
></TR
></TABLE
>
</P
><P
>&#13; You'll need to prepare the chipset for Ultra<SPAN
CLASS="acronym"
>DMA</SPAN
> beforehand. Also, see your manual page about hdparm for more information. Use this with extreme caution!
To set multiple sector mode I/O, use the command:
<TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="screen"
>&#13; [root@deep] /#<B
CLASS="command"
>/sbin/hdparm</B
> -m XX /dev/hda <EM
>or hdb, hdc etc</EM
>.
</PRE
></TD
></TR
></TABLE
>
Where XX is the maximum setting supported by your drive. The -i flag can be used to find the maximum setting supported by an installed drive: look for MaxMultSect in the output.
<TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="screen"
>&#13; [root@deep] /#<B
CLASS="command"
>/sbin/hdparm</B
> -i /dev/hda <EM
>or hdb, hdc etc</EM
>.
</PRE
></TD
></TR
></TABLE
>
</P
><P
>&#13; <DIV
CLASS="informalexample"
><A
NAME="AEN4877"
></A
><P
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="literallayout"
><TT
CLASS="computeroutput"
>&#13; /dev/hda:
Model=Maxtor 7540 AV, FwRev=GA7X4647, SerialNo=L1007YZS
Config={ HardSect NotMFM HdSw&#62;15uSec Fixed DTR&#62;5Mbs FmtGapReq }
RawCHS=1046/16/63, TrkSize=0, SectSize=0, ECCbytes=11
BuffType=3(DualPortCache), BuffSize=32kB, MaxMultSect=8, MultSect=8
DblWordIO=yes, maxPIO=2(fast), DMA=yes, maxDMA=1(medium)
CurCHS=523/32/63, CurSects=379584528, LBA=yes, LBA=yes, LBAsects=1054368
tDMA={min:150,rec:150}, DMA modes: sword0 sword1 *sword2 *mword0
IORDY=on/off, tPIO={min:240,w/IORDY:180}, PIO modes: mode3
</TT
>
</PRE
></TD
></TR
></TABLE
><P
></P
></DIV
>
</P
><P
>&#13; Multiple sector mode aka <SPAN
CLASS="acronym"
>IDE</SPAN
> Block Mode, is a feature of most modern <SPAN
CLASS="acronym"
>IDE</SPAN
> hard drives, permitting the transfer of multiple sectors per I/O
interrupt, rather than the usual one sector per interrupt. When this feature is enabled, it typically reduces operating system overhead for disk I/O by 30-50%. On many systems
it also provides increased data throughput of anywhere from 5% to 50%.
You can test the results of your changes by running hdparm in performance test mode:
<TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="screen"
>&#13; [root@deep] /#<B
CLASS="command"
>/sbin/hdparm</B
> -t /dev/hda <EM
>or hdb, hdc etc</EM
>.
</PRE
></TD
></TR
></TABLE
>
</P
><DIV
CLASS="tip"
><BLOCKQUOTE
CLASS="tip"
><P
><B
><SPAN
CLASS="inlinemediaobject"
><IMG
SRC="./images/Tip.gif"
ALT="Tip"
></IMG
></SPAN
>: </B
>
Once you have a set of hdparm options, you can put the commands in your <TT
CLASS="filename"
>/etc/rc.d/rc.local</TT
> file to run it every time you reboot the machine.
</P
></BLOCKQUOTE
></DIV
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="chap6sec73.html"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="index.html"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="chap6sec75.html"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>The atime and noatime attribute</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="gen-optim.html"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>Better manage your <SPAN
CLASS="acronym"
>TCP/IP</SPAN
> resources</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>
Reference in New Issue View Git Blame Copy Permalink