We've not been able to replicate your problem yet. One notable difference is our system-wide memory ulimit is larger (256 meg). Can you have your ulimit increased (it involves tuning the kernel with sam (or whatever tool you prefer) and rebooting)?
We are doing a big walk with your version to see if we can get the behavior you're seeing. It will take some time to complete. While we're waiting you could try to create the index with tsql using the same settings that dowalk would use. The following commands assume you are using default word expressions.
set indexmem=10000000;
set delexp=0;
set addexp='[\alnum\x80-\xff]{1,70}';
set addexp='[\alnum\x80-\xff.]{1,70}>>[.&'']=[\alnum\x80-\xff.]{1,70}';
set keepnoise=1;
create metamorph inverted index xhtmlbodv on html(Title\Description\Keywords\Meta\Body,Visited);
Here's something interesting. I tried the commands in 43 to create index with just one change to drop index xhtmlbodv. I executed it like this
tsql -d database-path -i command-file-path
and it failed with the same signal 11.
Then I removed line 4 (set addexp='[\alnum\x80-\xff.]{1,70}>>[.&'']=[\alnum\x80-\xff.]{1,70}'; ) and it worked fine. I not sure whether that addexp causes more memory utilization but it is definitely causing it to fail.
Yes. Each index expression will increase memory/disk usage, as will keepnoise. The expressions are listed in the "Word Definition" setting under "All walk settings". That particular expression will index things like numbers with decimal points, domain names, o'brien, and at&t.
You can remove that expression and still be able to perform most searches. You could also try changing the "70" (both of them) to something less like 20 or 30.