Lotus Notes
NSD Analysis
OK, so here goes on a lengthy post for the admins amongst us on NSD Analysis. An area I feel I know quite well …. however as you’ll remember from my last post this is based on publicly available information. NSD (or Notes System Diagnostic) is the name given to software bundled in Domino to give a snapshot of what the Domino system is doing. The tool produces text files with enormous ammounts of information and can be run manually or will run automatically during a crash. Interested ? …… (it may seem a bit dull but the information here could save you a lot of time!). Memory Without memory nothing works. In the operating system memory is divided into Kernel and User Address Space. The Kernel looks after the OS, hardware drivers and communications with the hardware. The User Address Space is where our applications run, and this includes Domino. So when Domino crashes it happens in the User Address Space ….. this means that Domino won’t directly cause a blue screen of death!!!! However Domino may, for example, be attempting to read or write to an area of disk which could cause a kernel memory error remembering that the kernel must deal with the disk. As we know, Domino is made up of a number of individual processes (nserver, nreplica, nrouter etc). Each of these processes all do their own little bit to make up the server. Each process is doing a number of tasks at any one time, these are called threads. And within each thread there is a specific set of individual actions. These are called function calls. Crashes (in a paragraph!) Yeah, Yeah, Blah, Blah so what does this mean for me? Well Domino is a fairly complex beast. Now and again a thread will try and use some memory which is reserved or in use by another process. This is a memory exception and at this point everything will go a bit messy. A panic will be recorded in the thread, Domino will freeze everything that it is doing and the nsd task will run. This will gain a snapshot of
OK, so here goes on a lengthy post for the admins amongst us on NSD Analysis. An area I feel I know quite well …. however as you’ll remember from my last post this is based on publicly available information. NSD (or Notes System Diagnostic) is the name given to software bundled in Domino to give a snapshot of what the Domino system is doing. The tool produces text files with enormous ammounts of information and can be run manually or will run automatically during a crash. Interested ? …… (it may seem a bit dull but the information here could save you a lot of time!). Memory Without memory nothing works. In the operating system memory is divided into Kernel and User Address Space. The Kernel looks after the OS, hardware drivers and communications with the hardware. The User Address Space is where our applications run, and this includes Domino. So when Domino crashes it happens in the User Address Space ….. this means that Domino won’t directly cause a blue screen of death!!!! However Domino may, for example, be attempting to read or write to an area of disk which could cause a kernel memory error remembering that the kernel must deal with the disk. As we know, Domino is made up of a number of individual processes (nserver, nreplica, nrouter etc). Each of these processes all do their own little bit to make up the server. Each process is doing a number of tasks at any one time, these are called threads. And within each thread there is a specific set of individual actions. These are called function calls. Crashes (in a paragraph!) Yeah, Yeah, Blah, Blah so what does this mean for me? Well Domino is a fairly complex beast. Now and again a thread will try and use some memory which is reserved or in use by another process. This is a memory exception and at this point everything will go a bit messy. A panic will be recorded in the thread, Domino will freeze everything that it is doing and the nsd task will run. This will gain a snapshot of