Saturday, June 27, 2009

Seven Million Files on NTFS

I had occasion to look into performance problems on a Windows 2003 server the other day. The server is running IIS and generally runs along tickety-boo. Then someone started to delete some files from an NTFS volume and the server practically locked up. That's when I was called in.

I quickly discovered that the one volume had approximately seven million files files on it. This amount of files will pose probems: even if the application(s) using the volume can cope, explorer.exe won't fair so well.

I've never been particularly impressed with Explorer's performance when large file operations are required, wheter that's working with a small number of large files, or a large number of small files. In fairness though, deleting seven million files is bound to take some time. That said, it shouldn't appear to lock up the entire system.

Any component of an operating system has its limits. Seven million files appears to be beyond what explorer on W2k3 can cope with by default. The application was also generating long files names with the dfferences in the names at the end of the filenames which poses an overhead for 8.3 filename generation. It is of course possible to tweak NTFS performance using fsutil to turn off 8.3 filename generation, but I favour leaving things at their defaults unless there is a compelling reason to do otherwise.

Debug logging had been left enabled in the application and was generating the files. It was not required in normal operations so was turned off. A quick format of the volume blew the files away quicker than a traditional delete could ever do. Log file generation reverted to a more respectable level and normal operations were resumed.

If you want to know more about the innards of NTFS, here's some good starting points:

What is NTFS?
How NTFS Works
NTFS Documentation
NTFS.com
Linux NTFS Wiki

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Monday, June 8, 2009

NAT Woes Resolved

Having started with Hosting365 I had to offload my NAT woes to a professional acquantance. Bottom line: the IP settings provided by the ISP were incorrect and the ZyWall NAT settings were caused by some finger trouble. All sorted now.

Saturday, June 6, 2009

All My Sons

My wife and I went to see All My Sons at The Gate Theatre last Tuesday. The performance was absolutely fanntastic. The set was impressive too. I first heard of this Arthur Miller play coming to The Gate Theatre back in February when we saw The Real Thing. At the time I figured it'd be one to see. How right I was.

The performances were the best I've ever seen on stage. Len Cariou's performance, his Gate debut, was particularly convincing. He wasn't acting: he was Joe Keller. Barbara Brennan's performance of, Kate, the distraught mother, is also first rate. And Garrett Lombard did a good Chris. In fact, at the risk of sounding like Father Ted, all the performances were very good.

To be fair, the material they have to work with is extraordinary. Miller delivers lines at just the right times, turning the audience's opinion of different characters from apathy to empathy as their inner conflicts are revealed.

This is without doubt a special production and is one to be seen if you have any chance. There were a couple of empty seats on Tuesday night, so if you have a free evening and a few Euro to spare, make a point to go see it. You won't be disappointed.

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