A movie with Julia Roberts or Meg Ryan is what I had in mind. Mladen Gogala Oracle DBA Phone:(203) 459-6855 Email:[EMAIL PROTECTED]
-----Original Message----- Sent: Monday, June 16, 2003 9:50 AM To: Multiple recipients of list ORACLE-L Mladen - Thanks for the clarification. Gee, does this mean no book? Well, maybe the movie would be some compensation. Cary - Thanks always for your willingness to share your knowledge. Looking forward to your book. Dennis Williams DBA, 80%OCP, 100% DBA Lifetouch, Inc. [EMAIL PROTECTED] -----Original Message----- Sent: Sunday, June 15, 2003 2:24 PM To: Multiple recipients of list ORACLE-L Dennis, to tell the truth, writing in oracle is not a big problem, as long as the redo files are not on RAID-5. Everything else can reside on RAID-5 without a visible performance impact. Second, RAID-5 vendors like EMC and Hitachi usually offer two versions of non-volatile cache: write-through one which essentially performs prefetch and a genuine full cache which caches both read and write calls. The latter type of cache, which is very expensive, is found on Symmetrix boxes only and not on former DG-Clariion boxes (talking EMC here). These types of RAID-5 implementation are usually referred to as RAID-6 or RAID-S. How to benchmark those? Well, the trick in benchmarking those systems is to do what one would never do with it's own system: put redo logs on RAID-5(6,S?), launch several threads of update intensive short transactions (OLTP mix) and count "user commits" from v$sysstat. Prior to that, establish a baseline with RAID 1+0 and see what is the difference. See how many commits would RAID-5 box record during the same time as RAID-1+0 box and you'll know the difference in speed. Also, make sure to pull out one of the disks while system is working and see what's the impact of resilvering. <RANT> As for the entertainment value, I would hope that Julia Roberts and Mel Gibson would consider making a movie about the RAID-5 conspiracy. Julia would be a DBA trying to purchase a RAID box and Mel Gibson would be a honest RAID-5 salesman which would uncover a nasty EMC, IBM and Hitachi conspiracy. You can tell that it is a fiction because of the phrase "honest RAID salesman". The only problem would be to teach the two of them how not to sound "nucular". </RANT> On 2003.06.15 14:14, DENNIS WILLIAMS wrote: > Mladen - I would propose another theory. Please consider this rant for > entertainment value, and hopefully to consider a book on this topic. > Usually companies request bids from several vendors. If you as a storage > salesperson always bid RAID1+0, you will always be underbid by your > competitors, receive no commissions, and in the end be fired. If you always > bid RAID5, you will probably receive some business, some commissions, and > keep your job. Now, pretend I'm a storage system salesperson. Which system > am I going to specify to the customer? > Now, if the customer insists on purchasing RAID1+0 or whatever, I'll > probably argue a little because I've been stung before where I was suckered > into bidding RAID1+0 and then my ignoramus competitor just blindly quoted > RAID5 and when it bubbled up to the V.P. he asked "why are you going with > the more expensive vendor"? And trying to quote a salesperson isn't a good > move at that point. > I thought Rachel had a good point on this topic awhile back. If you are a > top-notch consultant that is often called in to solve performance problems, > you have often cured them by switching from RAID5. So you have a lot of > confidence in it. But if you are the lowly on-site DBA just trying to hang > onto your job in the political turbulence, you usually don't have enough > facts to challenge the system administrators who trust their storage vendors > a lot more than a DBA that couldn't actually configure a storage system to > save his or her life. > So suppose I do try to challenge the system administrators. I say that > RAID1+0 will write faster than RAID5. The reply is "okay how much faster?" I > mumble that I've never seen any actual figures published anywhere. He or she > says maybe at the low level there is a slight advantage to RAID1+0, but with > a gig of battery-backed cache that won't be true. Or he or she asks "What > does Oracle recommend?". And on it goes. > Okay, I'm being provocative here. But how do I, a lowly DBA, prove which > is faster? Should I talk my system administrator into going to the trouble > of configuring a system both ways and run some tests? What type of tests > would be most useful? If I choose the wrong test, and RAID5 looks just as > good as RAID1+0, I'm sunk. Then for years to come when I try to make a point > at a meeting someone will say "yeah, is this another RAID1+0 theory?" > > Dennis Williams > DBA, 80%OCP, 100% DBA > Lifetouch, Inc. > [EMAIL PROTECTED] > > > -----Original Message----- > Sent: Sunday, June 15, 2003 2:49 AM > To: Multiple recipients of list ORACLE-L > > > RAID-5 microkernel has more lines of code then Oracle7? Wow! This is an > astonishing piece of information and if it wasn't coming from you, I'd > dismiss it as yet another conspiracy theory. > > On 2003.06.15 01:44, Cary Millsap wrote: > > > Meanwhile I have never understood why storage vendors would prefer > > > selling RAID5 over RAID10. > > > > ...Because if they don't sell RAID5, they don't recover the R&D costs of > > creating a RAID5 microkernel that has more lines of code than the Oracle7 > > executable. I'm not kidding. > > > > > > Cary Millsap > > Hotsos Enterprises, Ltd. > > http://www.hotsos.com > > > > Upcoming events: > > - Hotsos Clinic 101 in Dallas, Washington, Denver, Sydney > > - Hotsos Symposium 2004, March 7-10 Dallas > > - Visit www.hotsos.com for schedule details... > > > > > > -----Original Message----- > > Niall Litchfield > > Sent: Thursday, June 12, 2003 12:05 PM > > To: Multiple recipients of list ORACLE-L > > > > Jared writes > > > At the meeting last week I wore my 'No RAID 5' hat. > > > > > > Those of you at IOUG 99 in Denver may have seen it, I > > > wore it every day there. ;) > > > > I'm curious now. Pictures required. > > > > Meanwhile I have never understood why storage vendors would prefer > > selling RAID5 over RAID10. More disks=more profit surely? Also 10 > 5 > > therefore self evidently twice as good for all applications. Meanwhile > > we have this strange situation where performance consultants are > > publicising the fact that you have less need for performance consultants > > with RAID10 than with RAID5. > > > > Niall > > > > -- > > Please see the official ORACLE-L FAQ: http://www.orafaq.net > > -- > > Author: Niall Litchfield > > INET: [EMAIL PROTECTED] > > > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > > San Diego, California -- Mailing list and web hosting services > > --------------------------------------------------------------------- > > To REMOVE yourself from this mailing list, send an E-Mail message > > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > > the message BODY, include a line containing: UNSUB ORACLE-L > > (or the name of mailing list you want to be removed from). You may > > also send the HELP command for other information (like subscribing). > > > > -- > > Please see the official ORACLE-L FAQ: http://www.orafaq.net > > -- > > Author: Cary Millsap > > INET: [EMAIL PROTECTED] > > > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > > San Diego, California -- Mailing list and web hosting services > > --------------------------------------------------------------------- > > To REMOVE yourself from this mailing list, send an E-Mail message > > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > > the message BODY, include a line containing: UNSUB ORACLE-L > > (or the name of mailing list you want to be removed from). You may > > also send the HELP command for other information (like subscribing). > > > > -- > Mladen Gogala > Oracle DBA > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: Mladen Gogala > INET: [EMAIL PROTECTED] > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > San Diego, California -- Mailing list and web hosting services > --------------------------------------------------------------------- > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB ORACLE-L > (or the name of mailing list you want to be removed from). You may > also send the HELP command for other information (like subscribing). > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: DENNIS WILLIAMS > INET: [EMAIL PROTECTED] > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > San Diego, California -- Mailing list and web hosting services > --------------------------------------------------------------------- > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB ORACLE-L > (or the name of mailing list you want to be removed from). You may > also send the HELP command for other information (like subscribing). > -- Mladen Gogala Oracle DBA -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Mladen Gogala INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: DENNIS WILLIAMS INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Gogala, Mladen INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
