Re: [ADMIN] reconfiguring diskspace while upgrading to 8.2.5
Am Freitag, 28. Dezember 2007 schrieb Mark Steben: > As we go. I am investigating using the new tablespace facility to move our > biggest and most accessed I didn't see anything in your description about having the WAL on a separate disk. You should include that in your plans. -- Peter Eisentraut http://developer.postgresql.org/~petere/ ---(end of broadcast)--- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
Re: [ADMIN] reconfiguring diskspace while upgrading to 8.2.5
Postgres admin team, I posed this question last week. Probably a bad week to ask questions as many people off For the holidays so response was light. Thanks to Pete Eisentraut for his feedback. I'd like to pose the question again. Our upgrade time-table is getting close. Any and All feedback would be appreciated. Thank you, Mark Steben _ From: Mark Steben [mailto:[EMAIL PROTECTED] Sent: Friday, December 28, 2007 10:09 AM To: 'pgsql-admin@postgresql.org' Cc: '[EMAIL PROTECTED]'; 'David Parks'; 'Craig Brothers' Subject: reconfiguring diskspace while upgrading to 8.2.5 Admin team, We are upgrading from Postgres 7.4.5 to 8.2.5 in mid January. We are also adding new disks As we go. I am investigating using the new tablespace facility to move our biggest and most accessed Table to the new disk. Here are the statistics. We are running RAID 10 Current database size - 63 GIG Heavy accessed table to move: Table --- 7.4 GIG 2 indexes --- 3 GIG apiece 2 other indexes - 2.5 GIG apiece Current database disk configuration TOTAL space -- 404 GIG TOTAL spindles --- 3 TOTAL mirrors 3 New additional disk configuration TOTAL space 290 GIG TOTAL spindles --- 2 TOTAL mirrors --- 2 The choices we see are: 1. Adding the two new spindles to the other three making one huge logical partition And all 350+ tables and 400+ indexes continue to reside there 2. Keeping the two new spindles separate and dedicating the heavy access table And its 4 indexes to it. 3. Keeping the two new spindles separate and dedicating the heavy access table To it, but keeping the 4 indexes on the old partition. I know that maintaining almost 700 GIG of total disk space being utilized by a 63 GIG Database looks like disk-space overkill but we do expect massive growth over the Next 2 - 3 years. Any thoughts / comments would be appreciated. Also are there tools out there that monitor disk I/O and disk speed? Thanks for your time, Mark Steben Senior Database Administrator @utoRevenueT A Dominion Enterprises Company 480 Pleasant Street Suite B200 Lee, MA 01238 413-243-4800 Home Office 413-243-4809 Corporate Fax msteben mailto:[EMAIL PROTECTED]> @autorevenue.com Visit our new website at http://www.autorevenue.com/> www.autorevenue.com IMPORTANT: The information contained in this e-mail message is confidential and is intended only for the named addressee(s). If the reader of this e-mail message is not the intended recipient (or the individual responsible for the delivery of this e-mail message to the intended recipient), please be advised that any re-use, dissemination, distribution or copying of this e-mail message is prohibited. If you have received this e-mail message in error, please reply to the sender that you have received this e-mail message in error and then delete it. Thank you. Come Visit Us at NADA! Booth #5735N February 9th - February 12th Moscone Center in San Francisco, CA
Re: [ADMIN] reconfiguring diskspace while upgrading to 8.2.5
On Jan 2, 2008 9:04 AM, Mark Steben <[EMAIL PROTECTED]> wrote: > > Postgres admin team, > > We are upgrading from Postgres 7.4.5 to 8.2.5 in mid January. We are also > adding new disks > > As we go. I am investigating using the new tablespace facility to move our > biggest and most accessed I think my decision would be driven pretty strongly by what type of RAID controller (if any) and whether it had battery backed cache etc... Often, with a good controller with bbu cache, you're best off putting all your disks into one big RAID-10 and letting the RAID controller sort it out. For monitoring IO, use iostat and / or vmstat. ---(end of broadcast)--- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
Re: [ADMIN] reconfiguring diskspace while upgrading to 8.2.5
On Wed, Jan 02, 2008 at 10:04:53AM -0500, Mark Steben wrote: > The choices we see are: [. . .] I think this is likely to depend almost entirely on benchmarking your case, and testing the different possibilities. That said, except in extremely well-defined cases, it's often not a bad idea to make one large RAID anyway, because you sometimes find that your assumptions about your access patterns were wrong, and you've optimised for the wrong thing. In that case, the single large RAID offers greater flexibility, and if your controller is smart enough, the advantages are small enough that you don't gain enough for the loss in flexibility. I also want to point out that you need to test your workload _on 8.2_, and not make assumptions about disk use based on any experience you have gained from your production systems. Build a benchmark that looks like your production traffic, by all means, but don't extrapolate from 7.x to later versions for I/O information. There have been several huge strides in recent releases in reducing unecessary I/O, and 7.4 is susceptible to "checkpoint storms" that make even the most exotic storage hardware fail to perform well under some circumstances. Are your estimates of size, &c., based on a fresh load of the data? There are some lost-space issues in 7.4 that are solved in later releases, so you might find that some of your estimates of size are a little high. This matters for I/O, and might also affect your decision. > Also are there tools out there that monitor disk I/O and disk speed? Your OS should provide several. The basic ones are iostat and vmstat, but AIX has its own totally strange variants, and Solaris has some marvellous I/O tools. A ---(end of broadcast)--- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match