Hi, Using standard 7200 RPM SATA disks, I see around 50MB/s sequential write performance with write cache enabled, and around 3MB/s with the cache disabled. (Tested with 'dd'.) I understand this isn't NetBSD's fault, but it's somewhat unfortunate, since it means that for many workloads, the only way to get acceptable performance is to use an nvram write cache, or turn on the disk write cache and risk disk corruption on power failure. Has there been any progress on using disk features like explicit cache flush, or NCQ, to improve performance on such disks without the risk that enabling the write cache entails? (I'm currently using FreeBSD with ZFS on one system, mostly because of this performance issue, but I'd like to switch it to NetBSD.) Thanks, River.
Attachment:
pgpxxuTp53xA2.pgp
Description: PGP signature