Why use Oracle ASM for Oracle databases

Bart Sjerps Oracle 17 Comments

I’ve been in discussions with some customers recently about what is the best way to store Oracle database data. Needless to say that the foundation should be EMC infrastructure of course, but apart from that, what kind of volume manager and/or filesystem works best for performance and other features?

There are many volume managers, and many filesystems available, more or less dependent on what hardware and operating system you run the database.

Some have a long track record, some are new kids on the block. Some are part of the operating system, others are 3rd party add-ons, for which you might need to pay licenses.

One way of storing Oracle database data is Oracle ASM.
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Managing database performance SLA’s with quality of service

Bart Sjerps Oracle, Performance No Comments

A guy walks into the showroom of a Porsche dealer. He wants to buy a new set of hot wheels. The sales guy tells him about the latest technology in sports car design. This year’s model has active 4-wheel drive traction control, a very powerful engine (over 500 horsepower) with direct fuel injection, semi-automatic dual-clutch with seven speeds, and the whole car is weight-balanced to offer the best handling and cornering speeds. At the same time, carbon emissions per kilometer are the lowest in years and the car actually has green labels, so at least you can make yourself believe that it does not ruin the environment too much 😉

Porsche

“Great,” says the customer. “What’s the acceleration and top speed?”

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Thin Provisioning

Bart Sjerps General, Oracle No Comments

Some customers ask us – not surprisingly – how they can reduce their total cost of ownership in their information infrastructure even more. In response, I sometimes ask them what the utilization is of their storage systems.

Their answer: often something like 70% – you need of course some spare capacity for sudden application growth, so close to 100% is probably not a good idea.

Overallocating storage
Overallocating storage

If you really measure the utilization you often find other numbers. And I don’t mean the overhead of RAID, replication, spare drives, backup copies etc. because I consider these as required technology – invisible from the applications but needed for protection and so on. So the question is – of each net gigabyte of storage, how much is actually used by all applications?

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Desktop security: Application data got blurred

Bart Sjerps General No Comments

In the old days, when I started messing around with computers for fun as a young geek guy, computer security was pretty simple.

Amiga 2000
Amiga 2000

In those times we were using 8 or 16-bit PC’s with MS-DOS (for the poor guys) or, for the wealthy like myself, Commodore Amiga or comparable computers with real magic inside (who else around 1988 had 4-channel 8-bit stereo sound, 4096 colors, coprocessors for audio and graphics, true multitasking, a mouse-driven GUI handling multiple screens and windows, capable or running a word processor, graphics editor, sound tracker and some other stuff, all at the same time in 512 KB RAM?) (more…)

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Duplexing Oracle Redo logs?

Bart Sjerps FAQ, Oracle, Performance No Comments

A customer asked me recently what EMC’s advice is regarding duplexing Oracle redo logs. There is a thought behind this – Oracle redo logs are sensitive to data corruption – if redo logs are corrupt, there is no way to nicely recover the database to a technically consistent state (at least not without restoring data from backups).

This is what Oracle tells you:

Oracle recommends that you multiplex your redo log files; the loss of the log file information can be catastrophic if a recovery operation is required.

 

Duplexed Redo
Duplexed Redo

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