Hi Tim,

I've done this enough times that I think you can take a copy of your current changes file & a new squeak image, move them to a separate directory, rename the image file to match the changes file, then open the image file, and see all of your changes since the beginning of time with the "Recover changes" command.

Worth a shot at least.

Tim Johnson-2 wrote

Hi,

I have an image which had been running with only periodic interruption for many months, as it functions as a server to collect data. Over the past two weeks or so, I'd started working on some code in it again, some of which I liked, but which I'm afraid I may have now lost. (I am foolish, working in an image being used to collect data, but I have excuses.)

Is it possible for me to recover anything from the last 2-3 weeks from a .changes file? I do have a previous version of the same image, from November, but don't know how to load a different .changes file.

In case it matters, here's what went down:

Things seemed OK until today when I moved a window in Morphic and the VM crashed. (I had a dozen+ inspectors open on a dozen+ collections between 150 and 8000 in size.)

After the crash, I loaded the image up again and recovered my one changed method via Recover Changes. Then, feeling overconfident, I did a "save" instead of "Save as" :(. At some point during or after the save, Squeak stopped responding to user input. Activity Monitor showed CPU usage at only around 3% so after a while I just force-quit it.

Now if I try to load that image with the VM I'd been using, the VM crashes before even bringing up a window.

I got some output from running the VM through Terminal. Thinking I'd get more debug output, I tried it by compiling oscogvm/build.macos64x64/squeak.cog.spur and running SqueakDebug.app, but I was mistaken thinking SqueakDebug.app would dump any more to Terminal than regular Squeak.app. (Both output the same information and seem to crash in the same way.)

Anyhow, if anyone has any tips, or wants a copy of a broken image, please let me know. In any case, I'll just end with this quote from Ralph Johnson:

"One thing to remember is NEVER TRUST AN IMAGE! Images are extremely convenient and fairly fragile. Every so often you will kill an image, and you will lose everything in it. It is possible to recover from your changes log, but it is real pain if you have several weeks of work there to recover. I make it a point to build a new image once a week or so. Some people do it every day. It all depends on your style, I guess. Just because you saved an image doesn't mean that you can start it up again."

https://users.cs.duke.edu/~ola/courses/cps196/spr98/smalltalk/changesets.htm...

Thanks, Tim J

2-21-debug-out.txt (12K) <http://forum.world.st/attachment/5095840/0/2-21-debug-out.txt%3E;

-- Sent from: http://forum.world.st/Squeak-Dev-f45488.html

Hi Tim,

On Thu, 21 Feb 2019, Tim Johnson wrote:

Hi,

I have an image which had been running with only periodic interruption for many months, as it functions as a server to collect data. Over the past two weeks or so, I'd started working on some code in it again, some of which I liked, but which I'm afraid I may have now lost. (I am foolish, working in an image being used to collect data, but I have excuses.)

Is it possible for me to recover anything from the last 2-3 weeks from a .changes file? I do have a previous version of the same image, from November, but don't know how to load a different .changes file.

Yes. Open your previous version of the same image, open a File Browser in it, navigate to the changes file you want to recover changes from, select it and click on the "recent changes" button.

In case it matters, here's what went down:

Things seemed OK until today when I moved a window in Morphic and the VM crashed. (I had a dozen+ inspectors open on a dozen+ collections between 150 and 8000 in size.)

After the crash, I loaded the image up again and recovered my one changed method via Recover Changes. Then, feeling overconfident, I did a "save" instead of "Save as" :(. At some point during or after the save, Squeak stopped responding to user input. Activity Monitor showed CPU usage at only around 3% so after a while I just force-quit it.

Do you happen to collect data via sockets? If yes, you'll want to increase the maximum number of external semaphores your image has. By default it has 256. Each socket uses 3 of those and each file uses one. To increase the number to 8192, evaluate [ Smalltalk maxExternalSemaphores: 8192 ] before processing data; preferrably right after the image has started. You only have to do it once. If you save your image, it'll remember to use more external semaphores.

Levente

Now if I try to load that image with the VM I'd been using, the VM crashes before even bringing up a window.

I got some output from running the VM through Terminal. Thinking I'd get more debug output, I tried it by compiling oscogvm/build.macos64x64/squeak.cog.spur and running SqueakDebug.app, but I was mistaken thinking SqueakDebug.app would dump any more to Terminal than regular Squeak.app. (Both output the same information and seem to crash in the same way.)

Anyhow, if anyone has any tips, or wants a copy of a broken image, please let me know. In any case, I'll just end with this quote from Ralph Johnson:

"One thing to remember is NEVER TRUST AN IMAGE! Images are extremely convenient and fairly fragile. Every so often you will kill an image, and you will lose everything in it. It is possible to recover from your changes log, but it is real pain if you have several weeks of work there to recover. I make it a point to build a new image once a week or so. Some people do it every day. It all depends on your style, I guess. Just because you saved an image doesn't mean that you can start it up again."

https://users.cs.duke.edu/~ola/courses/cps196/spr98/smalltalk/changesets.htm...

Thanks, Tim J