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Home -> Community -> Mailing Lists -> Oracle-L -> RE: Raid 1 vs Raid 5 for tablespaces
I agree with your point, but it's often not what I see. It's all a
matter of degree.
A lot of the systems I see have 100% CPU utilization for hours on end, and upgrading is the wrong answer. If you're lucky, an upgrade will give you a 2x to 3x performance boost. Often after some SQL optimization, however, we'll reduce half the system's workload by a factor of 10,000 or more for the labor cost of maybe 1/4 of an upgrade's cost.
On one system I saw a few years ago, a variety of configuration errors (one of which was to use software striping and mirroring) actually accounted for almost 40% of the total CPU capacity on the system.
Cary Millsap
Hotsos Enterprises, Ltd.
http://www.hotsos.com
Upcoming events:
- Hotsos Clinic 101 in Denver, Sydney - Hotsos Symposium 2004, March 7-10 Dallas - Visit www.hotsos.com for schedule details...
-----Original Message-----
Mladen Gogala
Sent: Thursday, August 14, 2003 8:59 AM
To: Multiple recipients of list ORACLE-L
It robs of CPU power, that's true, but I've never seen a place where CPU
consumption would go
above 30% on average. If it does, then it's time to upgrade, or to quote
the
Taco Bell dog,
you need a bigger box. With approximately 70% left idle, companies
usually
have a few percent
of the CPU power to dedicate for RAID-0. After all, all those boxes have
nfs
daemons, sendmail,
lpd/lp/CUPS, xdm/gdm, automounter and some other daemons running.
Database
server seldomly needs
to export file systems, route mail (well, that comes in handy here and
there), manipulate printers
or scan the units for a music CD. If I want to play Kashmir or Stairway
To
Heaven, I'm not
going to (ab)use my database server for that purpose. Those few percent
spent on RAID-0 are quite
insignificant in comparison with the CPU percentage wasted by routed,
gated,
walld, talkd, xdm
and alike. The sad truth is that people no longer tune their systems,
because a bigger system is
actually cheaper then an SA needed to tune it properly. We're talking
about
the SUV mentality
translated into IT. You don't actually care whether an additional gallon
of
washing liquid is
wasting space in your SUV when you have enough room to accommodate a
medium
sized elementary
school in your vehicle.
-- Mladen Gogala Oracle DBA -----Original Message----- Millsap Sent: Wednesday, August 13, 2003 11:39 PM To: Multiple recipients of list ORACLE-L Problem with head-to-head price comparisons is that software RAID level 0 has hidden costs that a lot of folk might not understand before purchasing. For example, I would argue that software RAID level 0 costs a heck of a lot more than the list price, because it robs CPU capacity from your applications. Cary Millsap Hotsos Enterprises, Ltd. http://www.hotsos.com Upcoming events: - Hotsos Clinic 101 in Denver, Sydney - Hotsos Symposium 2004, March 7-10 Dallas - Visit www.hotsos.com for schedule details... -----Original Message----- Jesse, Rich Sent: Wednesday, August 13, 2003 11:49 AM To: Multiple recipients of list ORACLE-L How's about price? That's pretty important to some folk. :) Rich Rich Jesse System/Database Administrator rjesse_at_qtiworld.com Quad/Tech Inc, Sussex, WI USAReceived on Thu Aug 14 2003 - 09:59:32 CDT
> -----Original Message-----
> From: Matthew Zito [mailto:mzito_at_gridapp.com]
> Sent: Wednesday, August 13, 2003 11:14 AM
> To: Multiple recipients of list ORACLE-L
> Subject: RE: Raid 1 vs Raid 5 for tablespaces
>
>
>
>
> The _only_ even theoretical advantage to software RAID-0 is
> that software
> RAID implementations tend to have more flexibility than the
> hardware ones.
> For example, there are a number of software RAID
> implementations that allow
> you to grow RAID-0 volumes, something that is generally not allowed in
> hardware RAID, and most of those allow you to do it online.
> Some of the
> better software RAID implementations even allow for online volume type
> conversion - from RAID-1 to RAID-5 when adding a third disk
> to a mirrored
> pair, as a random example.
>
> Beyond that, there's no reason to have software RAID. Any
> other extraneous
> advantages can be gleaned by using a traditional VM on top of hardware
> RAID-ed devices. And even some of that stuff is better in
> hardware. :)
>
> Thanks,
> Matt
>
> --
> Matthew Zito
> GridApp Systems
-- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Jesse, Rich INET: Rich.Jesse_at_qtiworld.com 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: ListGuru_at_fatcity.com (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: cary.millsap_at_hotsos.com 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: ListGuru_at_fatcity.com (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). -------------------------------------------------------- Note: This message is for the named person's use only. It may contain confidential, proprietary or legally privileged information. No confidentiality or privilege is waived or lost by any mistransmission. If you receive this message in error, please immediately delete it and all copies of it from your system, destroy any hard copies of it and notify the sender. You must not, directly or indirectly, use, disclose, distribute, print, or copy any part of this message if you are not the intended recipient. Wang Trading LLC and any of its subsidiaries each reserve the right to monitor all e-mail communications through its networks. Any views expressed in this message are those of the individual sender, except where the message states otherwise and the sender is authorized to state them to be the views of any such entity. --------------------------------------------------------- -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Mladen Gogala INET: mladen_at_wangtrading.com 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: ListGuru_at_fatcity.com (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: cary.millsap_at_hotsos.com 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: ListGuru_at_fatcity.com (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).
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