Boston Linux & UNIX was originally founded in 1994 as part of The Boston Computer Society. We meet on the third Wednesday of each month at the Massachusetts Institute of Technology, in Building E51.

BLU Discuss list archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Discuss] linux on usb stick

Tom Metro wrote:
> VMware caching I/O wouldn't really explain it, if the underlying file
> system is still on a Flash device, which in Stephen's scenario it was.

When running natively, reads and writes are going to queue up behind 
fsync() calls and programs will block. It's unavoidable because flash 
has terrible write performance.

When running in a VM the VM system acknowledges fsync() calls and 
returns an "okay" status without actually performing the sync to disk. 
The virtualized guest will not block until the host blocks. A result of 
this is that you can get performance that appears to exceed the physical 
capabilities of the underlying device.

Rich P.

BLU is a member of BostonUserGroups
BLU is a member of BostonUserGroups
We also thank MIT for the use of their facilities.

Valid HTML 4.01! Valid CSS!

Boston Linux & Unix /