Re: [Qemu-devel] qemu-nbd very slow, patch available

2012-09-12 Thread Paolo Bonzini
Il 12/09/2012 10:25, Tristan Wibberley ha scritto: > The attached diff adds a commandline option "--cache=" with four modes > and makes no change to the default behaviour of qemu-nbd: > > --cache=writethrough [default, O_DSYNC, very slow, very resilient] > --cache=off [same as --nocache, O_DIR

[Qemu-devel] qemu-nbd very slow, patch available

2012-09-12 Thread Tristan Wibberley
Hello qemu devs, A couple of years ago Stephane Chazelas (https://launchpad.net/~stephane-chazelas) reported a performance issue with qemu-nbd due to the lack of an option to switch on writeback caching (ie a mode like any typical program that just modifies files of data where resilience is not pr