|
Tuesday, 01 December 2009 |
Too much of a good thing...
I have had a lot of people asking me about MySQL lately so I thought is was time to share something I learned. Too much caching space in MySQL can be a bad thing.
You would thing the more you can stuff your entire database into memory the better off you would be and the faster your system would work. That is not completely true. I have made mprovements by lowering table_cache variable on every version my MySQL 5. From what I have read this seems to be due to overhead managing file descriptors and caching tables. Like most things there is a point of diminishing returns when dealing with cache tables. At some point your hit rate is overtaken by the management threads.
This seems to work best. The read_rnd should be four times the sort and join buffer and they are four times the read buffer. Something like this;
sort_buffer_size = 16M
read_buffer_size = 4M
read_rnd_buffer_size = 64M
join_buffer_size = 16M
Send me feedback at Mark at Grennan.com |
|
Last Updated ( Tuesday, 01 December 2009 )
|
|
|
Building a Home VMWare Server |
|
Tuesday, 27 October 2009 |
I am building my own VMWare "Whitebox" server for home. I manage ESX system at work. I find using like equipment and software at home helps find, and resolve, issues before have to deal with them at work. I'm also interested in saving on my electric bill and increase my systems capabilities. With four computers in my small corner bedroom it gets hot. The air condition runs almost continuously during the summer. Along with the build project I'll be reporting on my energy savings.
I have three Linux servers to convert. I'll use ESXi to re-create them into virtual systems. They are, a firewall, a web/s data store server and an email server. The firewall is a small system running Untangle with a single disk, the web server is a Fedora Core system with a four disk RAID 4 and the email system runs Zimbra with mirror disks.
I'm also interested in experimenting with new systems. Some of these are Gentoo, MythTV (MythBuntu), OpenFiler, BackTrack and Zarafa email. I may report on these as well.
In the next new posts I'll go over:
- Hardware - What I purchased and why.
- Server Construction - How I put everything together.
- System Migration - Moving from physical systems to virtual systems.
- Network configuration - How one Internet connection is connected to all the virtual servers and my desktop.
- Benchmarks - How fast is everything and are there better configurations.
- Power savings - Did I really save on my power bill? What is my return on investment.
- Tweeks, Hacks and Tuning - Little things that make life better in a virtual world.
If you have questions about this project please email Mark @ Grennan.com or Tweet me at mgrennan
|
|
Last Updated ( Tuesday, 01 December 2009 )
|
|
Read more...
|
|
|
Simple Disaster Recovery Backup for VMware |
|
Thursday, 08 October 2009 |
Some time the simple scripts are the best. Disaster Recovery (DR) backups do not have to be made every day. At some places I've worked we made DR backups as little as one a year.
DR backups contain everything. You copy the entire envirement so you can buy new hardware and restore the operation of the needed services as quickly as posible without installing from scratch. Backups on tape are great but how can you restore the data if you don't have a tape server with the right OS and software in place ready to do the restore? VMware makes this eazy because it uses files as disks and you can make point in time snapshots. |
|
Last Updated ( Thursday, 08 October 2009 )
|
|
Read more...
|
|
|
|
<< Start < Prev 1 2 3 4 5 6 7 8 9 10 Next > End >>
|
| Results 1 - 4 of 56 |
