ADSM-L

RES: Database and log format question.

2004-04-28 10:36:04
Subject: RES: Database and log format question.
From: Paul van Dongen <paul AT VANGUARD-IT.COM DOT BR>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Wed, 28 Apr 2004 11:29:42 -0300
Hello All,

  I am not shure, but what I observed is that when you format the DB volumes on 
UNIX, this takes some time while the actual formatting is being done. On a 
Windows system, though, DB formats occur instantly, regardless of the size of 
the files. The actual formatting of the DB volumes on a Windows system seems to 
occur during the log mount phase.
  Using a small Windows system I formatted a 50GB database and a 100MB log 
(just to bring the server up) in 5 seconds! The log mount, however, lasted for 
about 90 minutes. 

Regards, 

Paul Gondim van Dongen
VANguard - Value Added Network guardians
http://www.vanguard-it.com.br
+55 81 3225-0353


-----Mensagem original-----
De: Remco Post [mailto:r.post AT SARA DOT NL] 
Enviada em: Wednesday, April 28, 2004 11:19 AM
Para: ADSM-L AT VM.MARIST DOT EDU
Assunto: Re: Database and log format question.


On Wed, 28 Apr 2004 15:52:58 +0200
Daniel Sparrman <Daniel.Sparrman AT EXIST DOT SE> wrote:

> Hi
> 
> My guess is that it's commiting log information. During DB restore, 
> the restore is sequential. However, when commiting the log 
> information, it is commiting the log on a per transaction basis. If 
> you're logs where highly used during your last db backup, this could 
> explain why it's taking so long for the TSM server to mount the log.
> 
> Remember, that during inital startup after a db restore, the TSM 
> server will do a recovery log roll-back, and commit all transactions 
> within the TSM log.
> 

Ok, now, Windows is different of course, but I just did about the same thing to 
an AIX server, TSM 5.2.1.2 on AIX 5.2 in 64 bit mode.

Logformatting took us about 5 minutes for a 13GB log, the db volumes were not 
formatted.

Restoring my 27 000 000 pages of database took about 2:30 hours, up and running 
in 3. Now, I do have about the fastest disks money can buy for my TSM server 
(15k RPM, 2 GB/s FC-AL), so you might expect a bit less performance on your 
windows system, but still, things should be about comparable.

Log mounting of a freshly formatted log should take about 0 seconds.

> Best Regards
> 
> Daniel Sparrman
> -----------------------------------
> Daniel Sparrman
> Exist i Stockholm AB
> Propellervägen 6B
> 183 62 TÄBY
> Växel: 08 - 754 98 00
> Mobil: 070 - 399 27 51
> 
> 
> 
> "Remeta, Mark" <MRemeta AT SELIGMANDATA DOT COM>
> Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
> 2004-04-28 15:47
> Please respond to
> "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
> 
> 
> To
> ADSM-L AT VM.MARIST DOT EDU
> cc
> 
> Subject
> Re: Database and log format question.
> 
> 
> 
> 
> 
> 
> ok the server specs are a quad 1.4ghz pentium 4, 4gb memory running 
> win2k advanced server. What I did was erase the old log and database 
> volumes, then do a dsmserv -k
> format with the log and database volume specs.
> It created the volumes and formatted the recovery log volumes rather
> quickly.
> After it format's the recovery log volumes it does a recovery log
> volume mount.
> This is what is taking so long.
> I've been monitoring the IO and it seems to be doing something to the
> database disk, perhaps formatting the database volumes too? I don't
> know. I've done this before but never with a database this large.
> 
> Thanks,
> Mark
> 
> 
> -----Original Message-----
> From: Justin Bleistein [mailto:justin.bleistein AT SUNGARD DOT COM]
> Sent: Wednesday, April 28, 2004 9:35 AM
> To: ADSM-L AT VM.MARIST DOT EDU
> Subject: Re: Database and log format question.
> 
> 
> 3 hours? Wow!. What's are the hardware specs of your tsm server? What 
> else is going on, on that system (topas, if AIX, or top)? I would 
> probably consider running either a database audit or re-org, then try 
> mounting it again. thanks!
> 
>       On more thing, are you starting the server up again in the
> foreground
> or background?. If your initially trying to start it up in
> the background, kill it and start it up in the foreground first then
> let it
> do all of it's redo log record and undo passes, as well as log mount.
> Then once it's up, and you get a tsm server prompt. Then halt the
> server and restart it in the background for production operation
> at that point. Just another thought.
> 
> --Justin Richard Bleistein
> 
> 
> |---------+---------------------------->
> |         |           "Remeta, Mark"   |
> |         |           <[email protected]|
> |         |           DATA.COM>        |
> |         |           Sent by: "ADSM:  |
> |         |           Dist Stor        |
> |         |           Manager"         |
> |         |           <[email protected]|
> |         |           .EDU>            |
> |         |                            |
> |         |                            |
> |         |           04/28/2004 09:19 |
> |         |           AM               |
> |         |           Please respond to|
> |         |           "ADSM: Dist Stor |
> |         |           Manager"         |
> |         |                            |
> |---------+---------------------------->
> 
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> |
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>   |       Subject:  Database and log format question.
> |
> 
> >--------------------------------------------------------------------
> >-------
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> 
> 
> 
> 
> Yesterday morning I had an incident and lost one of the drives I had 
> about half my database volumes defined on. I'm in the process of 
> reformatting the log and database volumes so I can do
> a database restore.
> The database is 100gb and my log size is 13gb.
> It's been mounting the log volumes for over 3 hours now.
> Does anyone have any experience with a database this large in as far
> as approximately how long it will take to format and mount the
> database/log volumes?
> 
> 
> Thanks in advance,
> Mark Remeta
> 
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-- 
Met vriendelijke groeten,

Remco Post

SARA - Reken- en Netwerkdiensten                      http://www.sara.nl
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