Mark Knecht wrote: > Hi, > I'm wondering if anyone has opinions (on this list? Right...) as to > the best file system type for running vmware images of Windows XP. As > best I can tell an 8GB C: drive shows up as 4x 2GB files and 1.5GB > DRAM is modeled in a file of its own: > >... > > I suppose that as Windows is operating within this image Windows > thinks it is reading or writing to what it considers a file but vmware > gets in the middle to somehow map where a small file is within this > larger 2GB entity.
Correct. > My usage model is heavily read dominated. I write stock data into a > file once and then read it hundreds of times to do work. I'm > investigating RAID striping to increase read speed but no matter what > the files appear to always be 2GB so I suspect XFS, Reiser or > something other than ext3 that I'm currently using would possibly make > a difference? The 2GB limit can be set at virtual disk creation time. Older versions of NTFS can not deal with bigger files, so VMWare gives you the option of splitting a larger disk image into 2GB segments. As far as I know, you can not change this after a virtual disk is created. > But would it be a big difference? How would I test it? Run iozone ( http://www.iozone.org/ ) > Any ideas warmly appreciated. > Mark You can create a new virtual disk as a single segment and copy your data into it. The disk read/write performance may not change much... You can also give the virtual machine direct access to a partition or physical disk, bypassing the host file system. Again, this may or not be better (speedwise) Roberto Waltman
