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From:Mike Ledet Date:December 4 2002 10:12pm
Subject:RE: Slow performance using 3.23 on RH 8.0
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Actually it is hardware Raid 0, not software.  I knew about the safety issue
but I had been told that from a performance stand-point that Raid 0 was the
fastest.

I've watched the disk activity on the IDE drive and there is next to none,
but I guess it's possible something is going on there.

Gnome is because linux is very new to me... I found the GUI to be
comfortable coming from a Windoze world.  Since I first installed I've had a
crash course in doing it from the command line (I'm managing a web and mail
server as well) so at some point I could probably undo it.  

I'll try the variables when I get a chance.

Just as an aside I had a friend running SQL Server on a 2000 box that is a
pretty similar configuration... he added the same 3 columns to a table with
5 keys and 3 times as many columns in less than 2 minutes.

-----Original Message-----
From: Adam Nelson [mailto:anelson@stripped]
Sent: Wednesday, December 04, 2002 4:35 PM
To: 'Ledet, Mike'; mysql@stripped
Subject: RE: Slow performance using 3.23 on RH 8.0


The first thing I would do is toss the ultra ata drive and just use the
scsi drives running raid1, raid0 just isn't safe and hardware raid1 is
much faster than you would think.  This may seem counter-intuitive, but
there are all sorts of bus issues that could be interfering.  You may
very well have more logging going on on the ata drive than you think.

Second, do not install X or gnome at all.  What's the point?

Third, look at these variables (although I doubt they will help much):

set-variable = table_cache=256
set-variable = tmp_table_size=256M

If this doesn't work, get in touch.

> -----Original Message-----
> From: Ledet, Mike [mailto:MLedet@stripped] 
> Sent: Wednesday, December 04, 2002 11:01 AM
> To: 'mysql@stripped'
> Subject: Slow performance using 3.23 on RH 8.0
> 
> 
> I'm running Mysql 3.23.52 on a Redhat 8.0 installation 
> booting to Gnome.
> The machine is a dual AMD 1800, 1 gig of ram, one Ultra ATA 
> IDE drive, and 2
> 18 gig scsi 10,000 RPM drives on a RAID controller running Raid 0.
> 
> I've got everything except /db on the IDE drive, /db is the 
> only thing on
> the raid array.
> 
> I've got a couple of smallish tables and one larger table 
> with about 7 gigs
> of data.  The larger table is a fixed row format table with 
> each row being
> 462 bytes wide.  I have a primary auto increment int column 
> and a unique
> index on a varchar 60.  Pack keys is off, delayed key writes on.
> 
> With this kind of hardware I was expecting pretty good 
> performance, but I
> haven't seen it yet.  I finally decided something was wrong 
> when I had to
> run an alter table on the 7 gig table, adding 3 columns, a 
> varchar 12, a
> varchar 50, and a datetime columm.... and it took over 10 
> HOURS to complete.
> 
> That seems way too slow to me...
> 
> I've included relevant portions (the uncommented portions) 
> from my.cnf, the
> OS installation was fairly vanilla, using defaults for just about
> everything.  The file system is ext3.
> 
> Any suggestions or things I haven't included that you need?  
> Sorry if I'm
> doing something really stupid here... relatively new to Linux 
> after a lot of
> years of windoze.
> 
> Thanks in advance
> 
> Mike
> 
> ********** my.cnf *************
> 
> [mysqld]
> port            = 3306
> socket          = /var/lib/mysql/mysql.sock
> datadir         = /db/mysql
> skip-locking
> set-variable    = key_buffer=500M
> set-variable    = max_allowed_packet=2M
> set-variable    = table_cache=512
> set-variable    = sort_buffer=22M
> set-variable    = record_buffer=22M
> set-variable    = thread_cache=8
> # Try number of CPU's*2 for thread_concurrency
> set-variable    = thread_concurrency=6
> set-variable    = myisam_sort_buffer_size=64M
> log-bin
> server-id       = 0
> tmpdir          = /tmp/
> [mysqldump]
> quick
> set-variable    = max_allowed_packet=16M
> 
> [mysql]
> no-auto-rehash
> # Remove the next comment character if you are not familiar with SQL
> #safe-updates
> 
> [isamchk]
> set-variable    = key_buffer=500M
> set-variable    = sort_buffer=8M
> set-variable    = read_buffer=10M
> set-variable    = write_buffer=30M
> 
> [myisamchk]
> set-variable    = key_buffer=500M
> set-variable    = sort_buffer=8M
> set-variable    = read_buffer=10M
> set-variable    = write_buffer=30M
> [mysqlhotcopy]
> interactive-timeout
> 
> 
> 
Thread
Slow performance using 3.23 on RH 8.0Mike Ledet4 Dec
  • Re: Slow performance using 3.23 on RH 8.0Nikolas Samios4 Dec
  • RE: Slow performance using 3.23 on RH 8.0Adam Nelson4 Dec
  • RE: Slow performance using 3.23 on RH 8.0Adam Nelson4 Dec
  • Re: Slow performance using 3.23 on RH 8.0Mirek Novak5 Dec
RE: Slow performance using 3.23 on RH 8.0Mike Ledet4 Dec
  • Re: Slow performance using 3.23 on RH 8.0Michael T. Babcock5 Dec
RE: Slow performance using 3.23 on RH 8.0Mike Ledet4 Dec
RE: Slow performance using 3.23 on RH 8.0Mike Ledet4 Dec
  • RE: Slow performance using 3.23 on RH 8.0Adam Nelson4 Dec
    • Re: Slow performance using 3.23 on RH 8.0Jeremy Zawodny5 Dec
RE: Slow performance using 3.23 on RH 8.0Mike Ledet4 Dec
  • RE: Slow performance using 3.23 on RH 8.0Adam Nelson4 Dec
RE: Slow performance using 3.23 on RH 8.0Mike Ledet4 Dec
RE: Slow performance using 3.23 on RH 8.0Jan Steinman5 Dec