| Subject: Paging IO with large files |
| Group: microsoft.public.winternals |
| Date: 8/6/2007 10:04:13 AM |
| From: "Villy Madsen" [Email Address Protection] |
I don't know where to go with this, perhaps someone can point me in the right direction. To put it in perspective: Systems affected: WIN/XP - started happening about summer of 06 Environment: Win/XP SP2 patched up The hardware is a P4 1.5 ghz with 1GB of real and 1.6GB of paging space allocated (of 4 GB). 1 physical drive with 3 partitions of 36GB, 98GB and 100GB Application: A VAX emulator - mounting two virtual disks (windows files) of 2GB and 4GB respectively (happened on smaller files as well but I can't quantify that) Compilers - various i/c GCC running under minGW and Microsoft C++ Systems - not always consistent The real system (not the virtual vax) starts writing like crazy - one byte for every byte on the virtual disk - and the page faults start climbing like crazy. - it appears to be one page fault for every 4K bytes witten... Bytes read are low example for a "VAX" that's been running for a couple of hours cpu - 10:20 ; MemUsage 15Mb ; Pk Mem 93mb; page faults 1,561,136; VM Size 532 MB; I/O Reads 692K; I/O writes : 98K; I/O Read Bytes 51Meg; I/O Write Bytes: 6.2GBytes While the "massive IO" is taking place, the virtual machine is hung. It starts happening when an IO event is executed by the virtual machine SCP. This io event could be a write, or a close or perhaps a read. It's not consistent in when it happens - but the most frequent and readily traceable event is when the virtual machine is shutting down. The "system shutdown" message is received on the VAX "console", the SCP closes the file that is the virtual disk and then windows goes crazy with the IO. I have looked at the process with process Explorer and NO files are memory mapped. I do not use disk compression and indexing is turned off. I use Symantec anti-virus, but the file extensions for the virtual disks are excluded. (also note - it DOES NOT happen when the files are opened. (I am even reasonably sure that it does not happen with the first read)) Additional information: It started happening suddenly _ Aug or Sep of 06. I tried running the "VAX system" on a laptop and it took forever to startup... It COULD have been coincidental with the install of SP2. The laptop is a "managed" system. I had used it on the laptop previously without noticing this problem. I am not the only one with the "problem". It never happened with w/98. Anyone have any ideas - or a suggestion as to where I should go for suggestions ?? Thanks Villy |
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