Question about swap files and XP
#1
Posted 25 August 2002 - 05:06 AM
#2
Posted 25 August 2002 - 01:35 PM
I always wanted to some how make a RAM drive and use it for the swap file.... ;(
#3
Posted 25 August 2002 - 05:01 PM
some apps... specially games require a nice big pagefile to play without getting all **tchy about virtual memory.
hero's4 is a pain
some of the better apps like pro/e and sdrc use a pagefile as a last resort
#4
Posted 25 August 2002 - 07:50 PM
#6
Posted 26 August 2002 - 05:02 PM
that should keep the hd from using it until its nessesary
#7
Posted 26 August 2002 - 11:27 PM
that should keep the hd from using it until its nessesary
I have heard that this tweak does nothing for 2k and XP. It supposedly only applies to NT4. Which makes perfect sense because if i use this tweak it doesn't do a god damn thing.
#8
Posted 26 August 2002 - 11:59 PM
turning it off killed my hd from constantly caching so i assumed it still worked.
the ibm drives arent near as bad as the seagate drives for that annoying click click, but my hd's never do anything 'cept load programs.
of course my scsi controllers dont work as well in xp so that may have something to do with it.
:x
#9
Posted 27 August 2002 - 06:53 PM
< 128MB RAM = 2xRAM for swapfile
128MB-256MB RAM = 1.5xRAM for swapfile
> 256MB RAM = 256MB for swapfile
Most of my applications tend to run in RAM anyway, and I usually get at least 512MB of RAM for any serious workstations (1GB for the last 9 that I have brought in). So a 512MB or more swapfile would be a waste of space that would simply get excessively fragmented over use.
#10
Posted 28 August 2002 - 08:10 PM
#11
Posted 28 August 2002 - 08:36 PM
but they arent very common.
#12
Posted 28 August 2002 - 09:13 PM
#13
Posted 28 August 2002 - 10:30 PM
#14
Posted 28 August 2002 - 11:28 PM
when i get home im going to try and open every program i own and see what happens
#15
Posted 30 August 2002 - 02:21 AM
#16
Posted 30 August 2002 - 03:07 AM
#17
Posted 30 August 2002 - 06:49 PM
It looks like you have several things confused into one single idea. So here's a couple of things for you to think about:
1. SQL Server has changed a GREAT deal since you were working with it directly, especially in the area of memory management.
2. You were developing applications against the server, rather than actually working on the server locally in more recent years. I have been doing both over this time, and it is the job of the developer to limit the traffic that is moved around during application activity (and to limit the damage the user can do, especially with update queries ;)).
3. Per SQL books online, the server defaults to running as many operations as possible directly in memory. This is why SQL server doesn't rely so heavily on the perception of free memory that the OS has, but rather "thinks" for itself. It handles memory differently in each of the OSs that are supported. For this reason, SQL server can be (and is) specifically designed to reduce and in many cases eliminate the need for the pagefile. Here's a quote:
Having a lot of physical I/O to the database files is an inherent factor of database software. By default, SQL Server tries to reach a balance between two goals:
Minimizing or eliminating pagefile I/O to concentrate I/O resources for reads and writes of the database files.
Minimizing physical I/O to the database files by maximizing the size of the buffer cache.
By default, the SQL Server 2000 editions dynamically manage the size of the address space for each instance. There are differences in the way Windows NT, Windows 2000, Windows 95, and Windows 98 report virtual memory usage to applications. Because of this, SQL Server 2000 uses different algorithms to manage memory on these operating systems.
Also, the topic of VMM (Virtual Memory Management) expressively states not to configure the VMM in SQL Server to exceed physical RAM as the server will take a large performance hit, and states that leaving it to assign memory dynamically is a better idea. However, I have some systems where that isn't possible (such as SQL and Exchange server on the same box as with the SBS edition from MS) and I have to configure the memory usage manually for both SQL and Exchange (btw, SQL's memory manager is a lot better Exchange's; Exchange doesn't know how to let go).
So, you might want to try working with the more current products, and then evaluate your memory needs. Also, try using the performance counters with everything installed and running under load for about a week, and then you can close up the pagefile (or add RAM) from there.
The pagefile was only used because systems needed more memory to work with than what was physically available (4GB in a regular 32bit environment, not withstanding special memory managers). If a system could run SQL server with 512MB of RAM and a 1.5GB swapfile, then why not drop or greatly reduce the swapfile if you go to 2GB of RAM? Why in the world would you want to *increase* it to 2GB+ since you added RAM? In fact, the only specific need that was listed for a large swapfile on smaller systems was if the Full Text Search Engine was installed with SQL server, which would make sense to some degree. But that's it, and I imagine that can still be offset with proper memory management.
#18
Posted 30 August 2002 - 07:25 PM
By default, tempdb autogrows as needed while SQL Server is running. Unlike other databases, however, it is reset to its initial size each time the database engine is started. If the size defined for tempdb is small, part of your system processing load may be taken up with autogrowing tempdb to the size needed to support your workload each time to restart SQL Server. You can avoid this overhead by using ALTER DATABASE to increase the size of tempdb.
How's that? Also, you might want to consider an MSDN subscription so you can keep up with this software if your clients cannot. Because one day you will find someone that is up to date and you will be running on out dated information.
#19
Posted 30 August 2002 - 07:55 PM
1. You can lock the size (as I mentioned earlier, but was ignored) of the tempdb, which is the same thing that you would do in a pagefile. Also, since it writes the file in a sequential fashion using a B-Tree layout (for faster tablescans) the dropping of the new tables should leave much more linear spots to put new tables in. And, since SQL server regulates the file growth aggressively, can be manually controlled, AND the tempdb is recreated every time the service is restarted most of your comments are moot. This is why some dbas have automated means of stopping and restarting the service occasionally to drop any orphaned connections/sessions, to manually free up any RAM (which isn't too much of an issue with this version), and to can the tempdb and rebuild it.
2. You can adjust the leading buffer percentage to whatever you want.

Now, taking a look at all of this, I think this illustrates how using a large amount of physical RAM and proper configuration of a system can lead someone to reduce or eliminate the pagefile in many cases.
#20
Posted 30 August 2002 - 09:07 PM

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