RE: OFA and Shared Storage
EMC storage is very reliable, no question. However, I have personally seen terrible SAN disasters on many vendors' SANs, but most of them on EMC (since I worked for them). Without going into specifics, the SAN problems I've seen were caused by (in rough order): 1) human error - changing SANs tends to be a heavily manual operations, with a huge margin for error. Plus the portion of the IT population that understands the care and feeding of SANs is negligible. 2) Firmware bugs in hardware - there have been some truly horrific firmware bugs in storage equipment, especially fibre channel switches. 3) Operating system/driver bugs - there's a lot of crummy code out there in general, I suppose As an aside, this is also almost the identical list that I have for the major reasons I've seen organizations instantiate Disaster Recovery procedures - an actual disaster is almost never the reason. The moral of the story is, while YMMV, I would always keep copies of truly critical things like redo logs, control files, etc. elsewhere, ideally on something completely disparate. Of course, the more disparate the "something" is, the harder it is to manage and while less prone to hardware error, is more prone to human error. So maybe the moral of the story is that you can't win? :) Thanks, Matt -- Matthew Zito GridApp Systems Email: [EMAIL PROTECTED] Cell: 646-220-3551 Phone: 212-358-8211 x 359 http://www.gridapp.com > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of Mercadante, Thomas F > Sent: Tuesday, September 23, 2003 8:45 AM > To: Multiple recipients of list ORACLE-L > Subject: RE: OFA and Shared Storage > > > except that in the 5 years I have been using EMC SAN, we have > *never* experienced an outage. never had to perform a > recovery because of SAN errors. never anything. > > Tom Mercadante > Oracle Certified Professional > > > -Original Message- > Sent: Monday, September 22, 2003 6:05 PM > To: Multiple recipients of list ORACLE-L > > > > EMC SAN disk has such an incredible uptime, that worrying > about losing > > things like control files are (almost) a thing of the past. > > Uptime is only one thing, there are several other errors that > might occur, like IO controller errors, memory/CPU glitches > and file system corruptions like Matthew already said.. > > Tanel. > > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: Tanel Poder > 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: Mercadante, Thomas F > 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: Matthew Zito 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).
RE: OFA and Shared Storage
except that in the 5 years I have been using EMC SAN, we have *never* experienced an outage. never had to perform a recovery because of SAN errors. never anything. Tom Mercadante Oracle Certified Professional -Original Message- Sent: Monday, September 22, 2003 6:05 PM To: Multiple recipients of list ORACLE-L > EMC SAN disk has such an incredible uptime, that worrying about losing > things like control files are (almost) a thing of the past. Uptime is only one thing, there are several other errors that might occur, like IO controller errors, memory/CPU glitches and file system corruptions like Matthew already said.. Tanel. -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Tanel Poder 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: Mercadante, Thomas F 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).
Re: OFA and Shared Storage
I'm way beyond the simple RAID-F systems these days. I now want mirrored RAID-F systems! We could call them RAID-F1, and they're unique. You might waste parity disks in the first place ... but then you mirror them. Mladen Gogala wrote: Files are kept safe simply by RAID-5 mechanism. RAID-5 protects against any single disk failure (double disk failure can wipe it all out) and that is precisely why Mogens is such a zealous proponent of RAID-5 systems. -- Mladen Gogala Oracle DBA -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Monday, September 22, 2003 2:05 PM To: Multiple recipients of list ORACLE-L Subject: OFA and Shared Storage I read some posts on here with shared storage such as SAN and Network Appliances its no longer necessary to multiplex datafiles on different disks, since the storage array handles that for you. How do you ensure that control files and redo log files are kept safely apart so that no one disk failure in the shared storage can take them all out? According to the OFA(well the abbreviated version I have in front of me) 4-5 disks is optimal for multiplexing. Does this no longer apply with shared storage? How do you ensure database available with shared storage? if your not multiplexing datafiles? I may have read some peoples posts incorrectly. Im just digging into backup and recovery. -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: <[EMAIL PROTECTED] 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). 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: =?ISO-8859-1?Q?Mogens_N=F8rgaard?= 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).
RE: OFA and Shared Storage
Mmmm...I posted at some point with a description of EMC's write strategy - here it is: "Some arrays actually don't even give you the option of write-through cache - on the symmetrix, for example, it is actually impossible for a write to go directly to disk. You have no choice but to cache writes. This is called, in EMC marketing parlance, a "Fast Write". When the cache is under pressure and the symm decides it needs to make more room in cache for an incoming write, it holds the write at the host port, flushes an in-cache write to disk, then places the incoming write in cache and acknowledges it to the host. This is a "Delayed Fast Write" - I love marketing talk. :)" Whether or not a write will hit spindles directly depends on a couple of factors: -Do you have write-back or write-through enabled? (write-back = cache writes and write-through=only cache reads) -How pressured is your cache? Some naive arrays won't throttle back active hosts and so if you're unfortunate enough to be sharing an array with a very write-heavy box, your writes could end up bypassing cache -how utilized are your disks? Some arrays will write directly to disk when the disks are very idle. The end result being, of course, it is completely dependent on your array. A quibbling little point - SAN is no different, from a what-is-cached standpoint, than NAS or direct-attached. It just happens that high-end arrays tend to have more intelligence internally and those tend to be the arrays that get hooked into SANs. As far as RAID-5 goes, some arrays are better than others. EMC happens to be particularly bad (at least on their last gen arrays - they claim huge performance increases on the new frames - ymmv), Hitachi tends to be pretty good. The bigger your write cache, the less the quality of the RAID-5 implementation matters. If you aren't pushing a whole lot of throughput, you'll never notice the difference between different RAID-5 implementations. Thanks, Matt -- Matthew Zito GridApp Systems Email: [EMAIL PROTECTED] Cell: 646-220-3551 Phone: 212-358-8211 x 359 http://www.gridapp.com > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of Craig Munday > Sent: Monday, September 22, 2003 6:40 PM > To: Multiple recipients of list ORACLE-L > Subject: RE: OFA and Shared Storage > > > Hi, > > I've tended to have performance problems with RAID-5 (slow write > times). Does SAN make this any better, ie. with large disk > caches etc? > > With SAN, do the redo logs still hit the spindles when a > commit is issued > (for example)? I seem to recall that the EMC Symmetrix > considers the write > to be done when the write request is in its cache and not > necessarily on > the disk. > > Cheers, > Craig. > > > > At 10:54 AM 22/09/2003 -0800, Mladen Gogala wrote: > >Files are kept safe simply by RAID-5 mechanism. RAID-5 > protects against > >any single disk failure (double disk failure can wipe it all > out) and > >that is precisely why Mogens is such a zealous proponent of RAID-5 > >systems. > > > >-- > >Mladen Gogala > >Oracle DBA > > > > > > > > > -Original Message- > > > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf > > > Of [EMAIL PROTECTED] > > > Sent: Monday, September 22, 2003 2:05 PM > > > To: Multiple recipients of list ORACLE-L > > > Subject: OFA and Shared Storage > > > > > > > > > I read some posts on here with shared storage such as SAN and > > > Network Appliances its no longer necessary to multiplex > datafiles on > > > different disks, since the storage array handles that for you. > > > > > > How do you ensure that control files and redo log files are kept > > > safely apart so that no one disk failure in the shared > storage can > > > take them all out? > > > > > > According to the OFA(well the abbreviated version I have > in front of > > > me) 4-5 disks is optimal for multiplexing. Does this no > longer apply > > > with shared storage? How do you ensure database available with > > > shared storage? if your not multiplexing datafiles? > > > > > > I may have read some peoples posts incorrectly. Im just > digging into > > > backup and recovery. > > > > > > -- > > > Please see the official ORACLE-L FAQ: http://www.orafaq.net > > > -- > > > Author: <[EMAIL PROTECTED] > > > INET: [EMAIL PROTECTED] > > > > > > Fat City Network Services-- 858-538-5051 > http://www.fatcity.com &g
RE: OFA and Shared Storage
Hi, I've tended to have performance problems with RAID-5 (slow write times). Does SAN make this any better, ie. with large disk caches etc? With SAN, do the redo logs still hit the spindles when a commit is issued (for example)? I seem to recall that the EMC Symmetrix considers the write to be done when the write request is in its cache and not necessarily on the disk. Cheers, Craig. At 10:54 AM 22/09/2003 -0800, Mladen Gogala wrote: Files are kept safe simply by RAID-5 mechanism. RAID-5 protects against any single disk failure (double disk failure can wipe it all out) and that is precisely why Mogens is such a zealous proponent of RAID-5 systems. -- Mladen Gogala Oracle DBA > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of [EMAIL PROTECTED] > Sent: Monday, September 22, 2003 2:05 PM > To: Multiple recipients of list ORACLE-L > Subject: OFA and Shared Storage > > > I read some posts on here with shared storage such as SAN and > Network Appliances its no longer necessary to multiplex > datafiles on different disks, since the storage array handles > that for you. > > How do you ensure that control files and redo log files are > kept safely apart so that no one disk failure in the shared > storage can take them all out? > > According to the OFA(well the abbreviated version I have in > front of me) 4-5 disks is optimal for multiplexing. Does this > no longer apply with shared storage? How do you ensure > database available with shared storage? if your not > multiplexing datafiles? > > I may have read some peoples posts incorrectly. Im just > digging into backup and recovery. > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: <[EMAIL PROTECTED] > 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). > 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: [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: Craig Munday 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).
Re: OFA and Shared Storage
> EMC SAN disk has such an incredible uptime, that worrying about losing > things like control files are (almost) a thing of the past. Uptime is only one thing, there are several other errors that might occur, like IO controller errors, memory/CPU glitches and file system corruptions like Matthew already said.. Tanel. -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Tanel Poder 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).
RE: OFA and Shared Storage
Rich There is a security guard putting empty boxes in your cube... :>P -Original Message- Sent: Monday, September 22, 2003 3:00 PM To: Multiple recipients of list ORACLE-L One "Lesson Learned" here is to keep at least one copy of the control files off of the SAN. OK, so ours is currently just an icky AutoRAID subsystem, but it has a separate power cord which can be accidentally kicked out of the locking socket, even when you're working on a completely different set of systems. Rich Rich Jesse System/Database Administrator [EMAIL PROTECTED] Quad/Tech Inc, Sussex, WI USA > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > Sent: Monday, September 22, 2003 1:05 PM > To: Multiple recipients of list ORACLE-L > Subject: OFA and Shared Storage > > > I read some posts on here with shared storage such as SAN and > Network Appliances its no longer necessary to multiplex > datafiles on different disks, since the storage array handles > that for you. > > How do you ensure that control files and redo log files are > kept safely apart so that no one disk failure in the shared > storage can take them all out? > > According to the OFA(well the abbreviated version I have in > front of me) 4-5 disks is optimal for multiplexing. Does this > no longer apply with shared storage? How do you ensure > database available with shared storage? if your not > multiplexing datafiles? > > I may have read some peoples posts incorrectly. Im just > digging into backup and recovery. -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Jesse, Rich 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: Odland, Brad 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).
RE: OFA and Shared Storage
One "Lesson Learned" here is to keep at least one copy of the control files off of the SAN. OK, so ours is currently just an icky AutoRAID subsystem, but it has a separate power cord which can be accidentally kicked out of the locking socket, even when you're working on a completely different set of systems. Rich Rich Jesse System/Database Administrator [EMAIL PROTECTED] Quad/Tech Inc, Sussex, WI USA > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > Sent: Monday, September 22, 2003 1:05 PM > To: Multiple recipients of list ORACLE-L > Subject: OFA and Shared Storage > > > I read some posts on here with shared storage such as SAN and > Network Appliances its no longer necessary to multiplex > datafiles on different disks, since the storage array handles > that for you. > > How do you ensure that control files and redo log files are > kept safely apart so that no one disk failure in the shared > storage can take them all out? > > According to the OFA(well the abbreviated version I have in > front of me) 4-5 disks is optimal for multiplexing. Does this > no longer apply with shared storage? How do you ensure > database available with shared storage? if your not > multiplexing datafiles? > > I may have read some peoples posts incorrectly. Im just > digging into backup and recovery. -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Jesse, Rich 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).
RE: OFA and Shared Storage
Well, you don't want to configure it such that all files are striped across all disks. Every array has a "Sweet spot" in terms of spindles-per-raid group, and most arrays start to degrade significantly beyond that point. The notion of striping at an array level is a little questionable to begin with - hardware striping is usually less flexible than software striping, though the usual disclaimers about cpu utilization on your host applies. It's funny you mention EMC as an example - the Symmetrix does not inherently stripe well. The only reason striped volumes on the Symm were created is because windows boxes could only see a maximum of 26 volumes over fibre channel (think about it...). With the emc "hypervolume" model where each volume was a mirrored copy of a chunk of disk (so was generally around 9GB), the only way to get larger disks was to combine hypervolumes to get metavolumes. Most UNIX customers were using software RAID to get larger volumes for management benefits and continue to do so today. As always, the clariion is a totally different critter - sorry if that's what you were referencing. Also, I have seen every major storage vendor have arrays burst into flames and lose data - so keep those backups handy Thanks, Matt -- Matthew Zito GridApp Systems Email: [EMAIL PROTECTED] Cell: 646-220-3551 Phone: 212-358-8211 x 359 http://www.gridapp.com > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of Mercadante, Thomas F > Sent: Monday, September 22, 2003 2:45 PM > To: Multiple recipients of list ORACLE-L > Subject: RE: OFA and Shared Storage > > > In my opinion, SAN storage begs the question about whether > OFA makes sense anymore. If you can configurte the SAN > storage so that all files are striped across all disk, then > everything is spread. And if the SAN is mirrored, then just > why are we working so hard? > > EMC SAN disk has such an incredible uptime, that worrying > about losing things like control files are (almost) a thing > of the past. > > Tom Mercadante > Oracle Certified Professional > -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Matthew Zito 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).
RE: OFA and Shared Storage
Well, its beyond no "need" to multiplex - it rolls right into "might not be possible" (though that's an extreme case). Basically, since today's large arrays have several layers of abstraction between the storage consumer and the physical spindles, it can be difficult to determine what physical spindles data is living on. >From a reliability standpoint, its always worthwhile to have extra copies of things you need floating around, though in the case of a large array a fault that is severe enough to cause data loss at an array level is probably catastrophic enough to cause data loss on the copy(ies) as well. The more likely scenario is filesystem corruption when a server goes down. Ask your storage administrator to work with you to put redolog copies on different RAID sets. If they look at you like you're crazy, get another storage administrator :) Or set up a meeting with your Large Storage Vendor - they have people on staff to help with things like that. Thanks, Matt -- Matthew Zito GridApp Systems Email: [EMAIL PROTECTED] Cell: 646-220-3551 Phone: 212-358-8211 x 359 http://www.gridapp.com > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of [EMAIL PROTECTED] > Sent: Monday, September 22, 2003 2:05 PM > To: Multiple recipients of list ORACLE-L > Subject: OFA and Shared Storage > > > I read some posts on here with shared storage such as SAN and > Network Appliances its no longer necessary to multiplex > datafiles on different disks, since the storage array handles > that for you. > > How do you ensure that control files and redo log files are > kept safely apart so that no one disk failure in the shared > storage can take them all out? > > According to the OFA(well the abbreviated version I have in > front of me) 4-5 disks is optimal for multiplexing. Does this > no longer apply with shared storage? How do you ensure > database available with shared storage? if your not > multiplexing datafiles? > > I may have read some peoples posts incorrectly. Im just > digging into backup and recovery. > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: <[EMAIL PROTECTED] > 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: Matthew Zito 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).
RE: OFA and Shared Storage
Title: RE: OFA and Shared Storage Greg, I agree that OFA is a great concept for basing your standards on. At least DBA's who manage several servers can find stuff without spending time querying the database to find stuff. But I worry less and less about spreading and balancing files across disk systems. Tom Mercadante Oracle Certified Professional -Original Message-From: Loughmiller, Greg [mailto:[EMAIL PROTECTED]Sent: Monday, September 22, 2003 3:00 PMTo: Multiple recipients of list ORACLE-LSubject: RE: OFA and Shared Storage we use a single/double file system.. The LUN is made up of multiple physical disks, striped/mirrored across the multiple spindles based on the storage requirements. The disk technology has come a long way. Plus there have been several bench marks/white papers similar to this topic... But we still use the OFA file structure to maintain the consistency across the many systems and databases... greg -Original Message- From: Mercadante, Thomas F [mailto:[EMAIL PROTECTED]] Sent: Monday, September 22, 2003 2:45 PM To: Multiple recipients of list ORACLE-L Subject: RE: OFA and Shared Storage In my opinion, SAN storage begs the question about whether OFA makes sense anymore. If you can configurte the SAN storage so that all files are striped across all disk, then everything is spread. And if the SAN is mirrored, then just why are we working so hard? EMC SAN disk has such an incredible uptime, that worrying about losing things like control files are (almost) a thing of the past. Tom Mercadante Oracle Certified Professional -Original Message- Sent: Monday, September 22, 2003 2:05 PM To: Multiple recipients of list ORACLE-L I read some posts on here with shared storage such as SAN and Network Appliances its no longer necessary to multiplex datafiles on different disks, since the storage array handles that for you. How do you ensure that control files and redo log files are kept safely apart so that no one disk failure in the shared storage can take them all out? According to the OFA(well the abbreviated version I have in front of me) 4-5 disks is optimal for multiplexing. Does this no longer apply with shared storage? How do you ensure database available with shared storage? if your not multiplexing datafiles? I may have read some peoples posts incorrectly. Im just digging into backup and recovery. -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: <[EMAIL PROTECTED] 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: Mercadante, Thomas F 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).
RE: OFA and Shared Storage
Files are kept safe simply by RAID-5 mechanism. RAID-5 protects against any single disk failure (double disk failure can wipe it all out) and that is precisely why Mogens is such a zealous proponent of RAID-5 systems. -- Mladen Gogala Oracle DBA > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of [EMAIL PROTECTED] > Sent: Monday, September 22, 2003 2:05 PM > To: Multiple recipients of list ORACLE-L > Subject: OFA and Shared Storage > > > I read some posts on here with shared storage such as SAN and > Network Appliances its no longer necessary to multiplex > datafiles on different disks, since the storage array handles > that for you. > > How do you ensure that control files and redo log files are > kept safely apart so that no one disk failure in the shared > storage can take them all out? > > According to the OFA(well the abbreviated version I have in > front of me) 4-5 disks is optimal for multiplexing. Does this > no longer apply with shared storage? How do you ensure > database available with shared storage? if your not > multiplexing datafiles? > > I may have read some peoples posts incorrectly. Im just > digging into backup and recovery. > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: <[EMAIL PROTECTED] > 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). > 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: [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).
RE: OFA and Shared Storage
Title: RE: OFA and Shared Storage we use a single/double file system.. The LUN is made up of multiple physical disks, striped/mirrored across the multiple spindles based on the storage requirements. The disk technology has come a long way. Plus there have been several bench marks/white papers similar to this topic... But we still use the OFA file structure to maintain the consistency across the many systems and databases... greg -Original Message- From: Mercadante, Thomas F [mailto:[EMAIL PROTECTED]] Sent: Monday, September 22, 2003 2:45 PM To: Multiple recipients of list ORACLE-L Subject: RE: OFA and Shared Storage In my opinion, SAN storage begs the question about whether OFA makes sense anymore. If you can configurte the SAN storage so that all files are striped across all disk, then everything is spread. And if the SAN is mirrored, then just why are we working so hard? EMC SAN disk has such an incredible uptime, that worrying about losing things like control files are (almost) a thing of the past. Tom Mercadante Oracle Certified Professional -Original Message- Sent: Monday, September 22, 2003 2:05 PM To: Multiple recipients of list ORACLE-L I read some posts on here with shared storage such as SAN and Network Appliances its no longer necessary to multiplex datafiles on different disks, since the storage array handles that for you. How do you ensure that control files and redo log files are kept safely apart so that no one disk failure in the shared storage can take them all out? According to the OFA(well the abbreviated version I have in front of me) 4-5 disks is optimal for multiplexing. Does this no longer apply with shared storage? How do you ensure database available with shared storage? if your not multiplexing datafiles? I may have read some peoples posts incorrectly. Im just digging into backup and recovery. -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: <[EMAIL PROTECTED] 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: Mercadante, Thomas F 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).
RE: OFA and Shared Storage
In my opinion, SAN storage begs the question about whether OFA makes sense anymore. If you can configurte the SAN storage so that all files are striped across all disk, then everything is spread. And if the SAN is mirrored, then just why are we working so hard? EMC SAN disk has such an incredible uptime, that worrying about losing things like control files are (almost) a thing of the past. Tom Mercadante Oracle Certified Professional -Original Message- Sent: Monday, September 22, 2003 2:05 PM To: Multiple recipients of list ORACLE-L I read some posts on here with shared storage such as SAN and Network Appliances its no longer necessary to multiplex datafiles on different disks, since the storage array handles that for you. How do you ensure that control files and redo log files are kept safely apart so that no one disk failure in the shared storage can take them all out? According to the OFA(well the abbreviated version I have in front of me) 4-5 disks is optimal for multiplexing. Does this no longer apply with shared storage? How do you ensure database available with shared storage? if your not multiplexing datafiles? I may have read some peoples posts incorrectly. Im just digging into backup and recovery. -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: <[EMAIL PROTECTED] 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: Mercadante, Thomas F 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).
