excess memory use

[paleolith]

Config: Retrospect Pro 7.6.111, Windows XP SP3 with latest updates, 1GB physical RAM and 3GM VM. Have been using Retrospect for nearly 15 years.

 

Every time I do a backup, even a small daily incremental, Retrospect appears to use all possible memory and causes other applications to be paged out. I spend probably several minutes every morning waiting for other applications to restore their paged-out memory. Java apps are hit particularly hard -- I wait 30-60 seconds for Moneydance alone. MS Word, Excel, Adobe Reader (especially bad), and many smaller apps take 20-30 seconds each to restore their memory.

 

When I upgraded from .5GB to 1GB of physical memory 3 or 4 years ago, I saw no improvement. (Clearly this has been going on for a long time.)

 

By contrast, the other backup program I'm using, Jungle Disk, appears to have no affect whatever on other apps' memory.

 

How can I tell Retrospect to limit the amount of memory it uses?

 

Edward

Edited October 21, 2008 by Guest

[Mayoff]

With Retrospect closed, how much free RAM is available on the system?

 

Retrospect is a memory and processor hog. 1 GB of RAM may not be enough depending on how busy your computer is.

 

How much free space do you have on the C: disk? You should have at least 10 to 15 GB free.

[paleolith]

With Retrospect closed, how much free RAM is available on the system?

Task Manager is currently showing:

 

  Physical Memory (K):
   Total        981488
   Available    152332
   System Cache 198644

 Commit Charge
   Total       1317472
   Limit       3847524
   Peak        1647000

Retrospect is in the mix but inactive and using 13MB. Closing Retrospect increased available memory by about 8MB and decreased the commit charge by about 17MB.

 

I don't know if I can make myself get up in the middle of the night to check memory use during the backup. I'll try to remember to check the system and other applications first thing in the morning before doing anything else.

 

Retrospect is a memory and processor hog.

I have no problem with the CPU use, only the memory. What exactly do you mean by "memory hog"? The docs recommend 512MB for Retrospect Pro. I have 1GB. That's total for the computer, not just for Retrospect. In fact, that's the same as recommended to run Windows XP, so Retrospect is presumably intended to use a lot less than 512MB. So from the docs, I'd say that if I'm starting with 160MB available (physical) and having severe paging problems after the backup, then Retrospect is not operating in line with its own doumentation. (The entire backup last night was under 500MB.)

 

It would help a lot if the docs gave figures for how much memory Retrospect needs for its own use. The docs don't say that the numbers are for running Retrospect in an otherwise empty mix, with all non-default services disabled, etc etc. But what does it mean? How much memory does Retrospect need after Windows and other apps have taken their share? (Or before the others get any, depending on your point of view. :eyes: )

 

If Windows XP were more efficient at paging, it wouldn't matter, but Windows appears to write a large number of very small memory pages, so it takes forever to bring them back in.

 

1 GB of RAM may not be enough depending on how busy your computer is.

What do you mean by busy? Are you talking for Retrospect or for everything else? Everything else is idle when Retrospect is doing the backup. Everything else runs fine except MS Access, which I seldom fire up. Opera and Eudora are normally the biggest memory users. If I disabled Retrospect and only depended on my Jungle Disk backups, I could go for days without seeing these problems.

 

In fact, when I had only a half GB of memory, everything but Retrospect and Access ran fine. I upgraded to 1GB in the hope of improving the performance of Access and Retrospect. It didn't seem to help either one. The appearance is that Retrospect and Access look at the available commit charge (rather than physical memory) and think they can use that much memory. Whether this is actually the case, I have no way of knowing, but it fits the symptoms.

 

How much free space do you have on the C: disk? You should have at least 10 to 15 GB free.

The C: drive has 25GB (out of 75GB) available. The external drive to which the backup is being written has something like 100GB available (I don't have access to it right now). I'm using "Retrospect defined grooming" on the backup set.

 

Edward

[Mayoff]

Only having about 20 MB of free RAM when Retrospect is closed would just not leave enough for Retrospect to run correctly. Retrospect will be forced to use lots of virtual memory. In general Retrospect may need 1 GB of free RAM for best performance with a single execution unit.

[paleolith]

First, please read my message. The free memory number I gave is not what you quoted. Not even close.

 

Second, if Retrospect needs 1GB of free RAM, then why is the recommended configuration 512MB total RAM?

 

Third, what justifies Retrospect needing 1GB when far less mature backup programs need a small fraction of that? Yes, Retrospect has far more capabilities, but those are not being used during the copy phase of a backup.

 

Edward

[Mayoff]

You are right, my math is wrong. 152332 K appears to be 148.76 MB (if my calculator is right), which is still not realistic for what Retrospect has to do.

 

The system requirements are found at:

http://www.emcinsignia.com/en/products/software/retroforwin/systemrequirements/

 

Depending on which product you are looking at, the minimum is between 512 and 1GB with as much as 2GB recommended.

 

Not even having 512 GB of RAM available for Retrospect will really limit it's performance and stability. You will also find the computer overall will work better with more RAM.

 

Your post indicates that you upgraded your RAM 3 or 4 years ago. Today's operating systems (you now have SP3) and programs tend to require more memory then 3 or 4 years ago.

[paleolith]

I don't have a specific reference, but based on reviews I've read, you are pretty much alone in claiming that SP3 requires more resources than SP1. The Microsoft web pages for installing SP3 do not even mention memory.

 

The web page you link to gives requirements for "Windows computers that run Retrospect". In the Retrospect Pro section, it does not distinguish between XP and Vista. Why not? I agree that the requirements will be different. Since the figures given are different from those in the help files which shipped with the product, I have to assume the numbers on the web page are for Vista, and that the numbers in the help files are for XP. As previously stated, I'm running XP. (For as long as I can.)

 

You still haven't answered my original question -- is there a way to tell Retrospect to limit its memory use, effectively operate in a partition.

 

But don't bother. I give up. I didn't want to, but the time has come. Ironically, the difficulty now is that there are too many choices.

 

Edward

[Mayoff]

there a way to tell Retrospect to limit its memory use, effectively operate in a partition.

 

No, Sorry.

 

In the end, your ultimate goal is to get better performance from Retrospect. My recommendation would be more RAM (which is very probably not more then $100 or $200 at the high end), which would a good thing for everything you do on this computer.

 

I think most Retrospect users in the forum would agree.