DanielSmedegaardBuus

less info
317 reputation
211
bio website danielsmedegaardbuus.dk
location Denmark
age 37
visits member for 3 years, 4 months
seen May 6 at 7:56

Jul
2
awarded  Curious
Apr
24
awarded  Caucus
Dec
1
awarded  Yearling
Nov
12
revised Reconfiguring, then deleting obsolete pagefile.sys from C: in one go using a batch script
added 238 characters in body
Nov
11
comment Reconfiguring, then deleting obsolete pagefile.sys from C: in one go using a batch script
@Bob Thank you! I think I might be able to decipher something to do with my installation based on that. I'll report back :)
Nov
11
revised Reconfiguring, then deleting obsolete pagefile.sys from C: in one go using a batch script
added 422 characters in body
Nov
11
asked Reconfiguring, then deleting obsolete pagefile.sys from C: in one go using a batch script
Nov
11
accepted Disable disk caching in Windows XP using the command line?
Nov
11
comment Disable disk caching in Windows XP using the command line?
OS-level caching is turned off all the time. You feel this in Windows (and AFAIK all other OSes) for example with USB sticks where the write cache is OFF by default, to avoid losing data if you just chug it out. In OSes other than Windows, this is achieved by mounting your drive with the /sync/ option, turning off caching for that partition. Again, has nothing to do with the drive. It has to do with the filesystem and optimizing reads and writes either for speed or security.
Nov
11
comment Disable disk caching in Windows XP using the command line?
You seem to be mixing together OS caching and drive fundamentals. First of all, you can write a single byte to disk. But you have to read 1 chunk of data, change it and write it back. That's probably 512 bytes or 4k with spinning media, considerably more with most types of solid state media. Whether you, the OS, a driver, or the disk does it, it'll happen. (E.g. 4k drives faking 512B do some of it for you, SSDs do a lot of it).
Nov
4
comment Disable disk caching in Windows XP using the command line?
Pass the request through? What do you mean? The write request? How would that not get passed through either way? The only difference I can see is whether the writes are queued in guest RAM and then flushed intermittently to the host (cache), or the writes are queued in the host cache and flushed intermittently to disk. As my ATTO benchmarks display, I/O performance is the same. What do you mean about me missing the point of the write cache? My point is there's already a write cache on the host, so another one in the guest isn't gonna help much with performance.
Nov
3
comment Disable disk caching in Windows XP using the command line?
Come to think of it, this sort of optimization seems to be a no-brainer to implement in the VMware Tools in the first place, so that's probably what's happening already.
Nov
3
answered Disable disk caching in Windows XP using the command line?
Nov
3
comment Disable disk caching in Windows XP using the command line?
@techie007 — As you can see from my edit, there's no real benefit at all! Thanks for making me test that :)
Nov
3
revised Disable disk caching in Windows XP using the command line?
added 971 characters in body
Nov
3
comment Disable disk caching in Windows XP using the command line?
@techie007 — That's a really good question. I'm just assuming the effect would be less memory consumption. I'll do some tests and report back.
Nov
3
answered Disable disk caching in Windows XP using the command line?
Nov
3
revised Disable disk caching in Windows XP using the command line?
Added benchmarks screenshot
Nov
3
comment Disable disk caching in Windows XP using the command line?
Well, because I already have write caching on my host. So any write operation would already return pretty much immediately, even when synchronized, as the host OS eventually gets the write request, throws it in the cache, and returns. Also, I'm on a 2013 Air with 700+ MB/s reads and writes. Plus, most of what I'd be writing would be to shared folders on the host via vmhgfs.
Nov
3
comment Disable disk caching in Windows XP using the command line?
Hi David :) Thanks for responding! I think I may have phrased myself badly... You might be right about read caching, but at least we have an option to disable write caching (which is disabled by default for USB sticks, for instance). This is easily disabled via GUI, but I'd like to do it from the command line. And if it's possible (which you suggest not), the same for read caching. Cheers :)