I don't think this is a PixInsight problem, but I thought I would post it in case some one else using linux runs into it. I was going through Mercieca's tutorial and got up to the LocalNormalization step. The first time I ran it - with 29 light files - it crashed. The PI window just disappeared. I ran it again invoking PI from a terminal and saw this in the window after it stopped:
./PixInsight.sh: line 35: 5982 Killed /opt/PixInsight/bin/./PixInsight
It didn't throw an exception, it was killed. So I looked in /var/log/syslog and saw this:
May 15 15:02:58 ralph kernel: [ 589.493946] Out of memory: Kill process 2927 (PixInsight) score 898 or sacrifice child
May 15 15:02:58 ralph kernel: [ 589.493982] Killed process 2927 (PixInsight) total-vm:13927400kB, anon-rss:7585060kB, file-rss:0kB, shmem-rss:12744kB
May 15 15:02:58 ralph kernel: [ 589.812026] oom_reaper: reaped process 2927 (PixInsight), now anon-rss:0kB, file-rss:0kB, shmem-rss:12876kB
The oom killer killed it. My system has 8GB of ram (which I used to think was a lot!). The files are all .xisf files and each one is 289MB. By trial and error I found it could process at most 3 files at a time. I thought there might be bug in some other program using memory and not freeing it, so I rebooted the machine to start clean, but it still failed the same way if I try to process 4 or more files with LocalNormalization.