| 1 |
Mark Knecht wrote: |
| 2 |
> Hi, |
| 3 |
> I'm wondering if anyone has opinions (on this list? Right...) as to |
| 4 |
> the best file system type for running vmware images of Windows XP. As |
| 5 |
> best I can tell an 8GB C: drive shows up as 4x 2GB files and 1.5GB |
| 6 |
> DRAM is modeled in a file of its own: |
| 7 |
> |
| 8 |
>... |
| 9 |
> |
| 10 |
> I suppose that as Windows is operating within this image Windows |
| 11 |
> thinks it is reading or writing to what it considers a file but vmware |
| 12 |
> gets in the middle to somehow map where a small file is within this |
| 13 |
> larger 2GB entity. |
| 14 |
|
| 15 |
Correct. |
| 16 |
|
| 17 |
> My usage model is heavily read dominated. I write stock data into a |
| 18 |
> file once and then read it hundreds of times to do work. I'm |
| 19 |
> investigating RAID striping to increase read speed but no matter what |
| 20 |
> the files appear to always be 2GB so I suspect XFS, Reiser or |
| 21 |
> something other than ext3 that I'm currently using would possibly make |
| 22 |
> a difference? |
| 23 |
|
| 24 |
The 2GB limit can be set at virtual disk creation time. Older versions |
| 25 |
of NTFS can not deal with bigger files, so VMWare gives you the option |
| 26 |
of splitting a larger disk image into 2GB segments. As far as I know, you |
| 27 |
can not change this after a virtual disk is created. |
| 28 |
|
| 29 |
> But would it be a big difference? How would I test it? |
| 30 |
|
| 31 |
Run iozone ( http://www.iozone.org/ ) |
| 32 |
|
| 33 |
> Any ideas warmly appreciated. |
| 34 |
> Mark |
| 35 |
|
| 36 |
You can create a new virtual disk as a single segment and copy your data |
| 37 |
into it. The disk read/write performance may not change much... |
| 38 |
|
| 39 |
You can also give the virtual machine direct access to a partition or |
| 40 |
physical disk, bypassing the host file system. Again, this may or not be |
| 41 |
better (speedwise) |
| 42 |
|
| 43 |
|
| 44 |
Roberto Waltman |
Archives