Stuart D. Gathman wrote: >> How does SATA fit in with all of this? Is it basically the same >> limitations on the bus as IDE/PATA, so that you'd really not want to put >> more than 1 device per bus? > > SATA mandates at most 1 disk per channel, making the issue moot. It is > still true that there is only one active disk on a bus. But then there > is only one disk on a bus. Newer SATA drives, with proper newer controllers and proper device driver support will support NCQ (native command queueing), which allows the drive to re-order requests. It appears that the Linux ACHI and Nvidia SATA drivers support this capability in recent kernels. Of course, any of the re-ordering (SCSI TCQ, or SATA NCQ) requires filesystem and driver support of write barriers for reliability. Write barriers are not implement in DM, hence LVM, so there is a reliability risk in going with this kind of solution. Depending on the filesystem this can result in power failures resulting in files having inconsistent data. Dave _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
