On 07/12/13 19:11, Alexander Hall wrote: > On 07/12/13 23:50, Nathan Goings wrote: ... >> However, when I run `dd if=/dev/zero of=/dev/wd0c bs=1M' After 3-4 > > use the raw device, /dev/rwd0c, not the block device. I have found close > to no speed improvements with bs > 64k.
A few years ago, after someone said basically the same thing (actually, I think it was more emphatic -- as in, "it is impossible to see gains beyond ..."), I played with it and saw significant gains well beyond bs=64k for raw devices. I'd be surprised if individual experience didn't vary, though. Personally, I like bs=1m for another reason, though. "pkill -INFO dd" produces very readable output. >> hours, it's only running at ~2.4MB/s. CPU usage is about 30%. >> >> First, shouldn't SATA drives be sd0? (Looked in BIOS, can't find any >> SATA-to-IDE options enabled) Second, what can I do to speed it up? or >> troubleshoot it at least? well, maybe they SHOULD be (philosophically), but they WILL be whatever your controller hardware supports. If your controller is ahci(4) compliant, it will be sd(4) devices, if it isn't, it ends up being pciide(4) and wd(4). Nick.
