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Questions tagged [strace]

86 questions
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mongodb mystery crashes with sigkill under strace

I have a mongodb instance that seems to crash roughly once a day. I don't see any useful information in the mongo log file. All is well and then the process is just crashed with no additional information logged. I ran it under strace in hopes of…
Peter Lyons
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Mysql killing the CPU with gettimeofday

I have a problem with mysql killing the CPU on a Debian Squeeze 64. This is a development machine on a VPS so I stopped all the other services, including apache2. The mysql version is 5.1.49. This is the log when mysql starts : Feb 6 19:03:40…
noru
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Apache strace to hunt down a memory leak

We have a server with a memory issue: the server keeps allocating itself memory and doesn't release it. We're running Apache. I set MaxReqsPerClient to a really low value just so the threads don't hold a lot of memory, but has anyone seen calls like…
Zipp
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WSGI cannot access a file, but permissions are correct

I am debugging a problem where MoinMoin on CentOS is throwing a permissions error, but I can't track down where the problematic file / directory is. I ran strace -vp on the apache pid; when I have the problem I see this: epoll_wait(10,…
Mike Pennington
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Cant run programs under strace

I'm trying to run this simple program ls under strace and it wouldnt let me. Can you guys think of why this be the case? [jeffjose@skipper ~]$ strace ls strace: ptrace(PTRACE_TRACEME, ...): Permission denied I'm on Fedora 17b, and my shell is tcsh.…
jeffjose
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Long page loads - problems with DNS lookup?

I've noticed my web server takes a long time to load pages recently. Using Firebug, I realised it takes around 4s for the DNS lookup: Connecting: 304ms Sending: 0ms Waiting: 3.45s Receiving: 0ms I thought that was a long time to wait for a HTTP…
hohner
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which pid to use to strace my apache

My apache2 is using running slowly. A single PHP file is takes long time to process. The server is live. I dont want to restart it. So I thought I attach strace to it and check whats happening. So I run strace -p `cat /var/run/apache2.pid…
Shiplu Mokaddim
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How to analyze system calls when your disk is in read only and strace output is "Bus error"?

We have a HW problem with the disks, that made all the mount points to be read only. Output of dmesg: end_request: I/O error, dev sda, sector 15574609 sd 0:0:0:0: SCSI error: return code = 0x00040000 We want to analyze a program that is currently…
ompemi
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Performance problem when launching GUI applications under gnome while connected to VPN

I'm experiencing a severe performance problem starting apps but only when connected to my office VPN. It appears to be related to gnome-session. I believe the following is the relevant strace from simply starting gnome-terminal (but it's a similar…
nicerobot
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ls -l freezes terminal locally and remotely

I've been reading other SF threads regarding ls not returning results or freezing and stalling terminal sessions and it appears they usually the fault of network problems. My problem however, occurs both over remote SSH sessions but also if I am…
Jake Wilson
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how to see the verbose output of a process that is running that writes to a file (shred)

I am running the shred command to securely wipe some storage. I would like to see its progress, but have lost the ssh terminal that was running the command. Is there a way that I can use to see the verbose output of the shred command from a new ssh…
miller the gorilla
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read system call freeze

I have a VPS which sometimes suddenly got stuck. Recently I found ssh session will get stuck when I run ps aux. After run strace ps aux I got below. stat("/proc/1573", {st_mode=S_IFDIR|0555, st_size=0, ...}) = 0 openat(AT_FDCWD, "/proc/1573/stat",…
Eric
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What's the best approach to find out in doing what a Linux OS process is stuck?

Oracle DBA here! No experience at all in troubleshooting Linux performance... I need to identify the bottleneck in an Oracle database running on Oracle Linux. The same procedure runs fine on other VMs, so the problem is specific to a specific VM…
Massimo Pasquini
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Simple command to display in terminal the network activity of a command? A better formatted strace?

I want to debug a program which makes a simple network connection. Is there any command which will print the network activity of a command, something that will show me (e.g. in a hexdump) what is being sent & received. strace -e trace=%network…
Amandasaurus
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Record SSH commands sent to a Mac from Windows

I've got a bit of a puzzler - I am an administrator on both a Windows 10 and a Mac Catalina machine. The Windows machine is currently running software that has a known bug - SSH commands are sent to a Mac by a large piece of .NET Software that is…
Coruscate5
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