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IO WAIT is High
Pacifier
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Post: #21
RE: IO WAIT is High

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But how can i comment log-bin. What if i need to restore data in case of failure?. Is bin logging done for replication only?

If you don't do nightly backups, then keep using the logs although I don't really like the idea of using them for that purpose.

Quote:
What exactly is the disadv of the above? How will a 73g SCSI or 80gb 10,000 RPM SATA - II disk assigned to MySQL help?

The issue here is the same disk is shared between httpd and MySQL making it usage very high. If you move your MySQL data on another disk, the data will be served off that drive and it will split the I/O load between those two drives. I won't get on the hardware side and or formatting/mounting the disk, but once you have the second disk installed and mounted, you can move MySQL data to it using the article; How To: Move MySQL to a Second drive ..

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Does it have the same implication of having a seperate DB server?

Well, you have one advantage here, i.e. network. Data from same server is usually faster locally than on a network. Ofcourse, it doesn't implies it's a separate MySQL server, but the MySQL is using a separate disk to split the I/O load.

09-11-2006 01:19 PM
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ratheesh
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Post: #22
RE: IO WAIT is High

Actually we do nightly backups. Then do we really require the bin logging?
When does the bin logging come in handy other than for replication?

09-12-2006 05:32 AM
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Pacifier
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Post: #23
RE: IO WAIT is High

It isn't really needed if you do nightly backups Smile ..

09-12-2006 05:35 PM
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ratheesh
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Post: #24
RE: IO WAIT is High

Oh god... It happened yesterday too... This time it was deadly....
See the attached mytop snapshot. How is this possible, queries taking 1500 seconds....
Also see the Apache status...

I m worried. Whats wrong?

Thanks,
Ratheesh



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.htm File  Apache Status Sept 12.htm (Size: 55.24 KB / Downloads: 1)
09-13-2006 09:09 AM
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Pacifier
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Post: #25
RE: IO WAIT is High

Make use of all what I had mentioned in my earlier posts and do the changes. It should help. The last resolution is to put less work on MySQL and rewrite your queries to drop things that let MySQL do the hard work and instead let the PHP do it. (esp. if MySQL needs to use temporary files for that job -- EXPLAIN's your friend)

It is possible for a query to take that long when you're under heavy load.

09-13-2006 04:44 PM
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