I hope this isn't stating the obvious, but I asume you have used hdparm to adjust the default setting on your drives appropriatly (i.e. dma). I have 4 disks striped and get average sequential throuput of at least 40mb/s and 35mb/s (dd to /dev/null) on only 2 disks. cpu is approx 60% system (666mhz system). If I have the disks untuned I get %100 cpu, machine "stuttering" and throuput 10 times less. Duncan On Friday 23 Nov 2001 4:17 am, you wrote: > Hi all, > > All right. I've got LVM installed and running on 2 30GB IDE drives, a VG on > each, and the partitions divided just about evenly between them. This is on > a 1GHz Athlon with 640MB of RAM. I am running Debian/sid with lvm 1.0.1rc4 > and kernel 2.4.13. > > A few things I have noticed in the week or so that I have been using LVM. > First, the drive activity light stays lit all the time. I'm not terribly > worried about it, since things seem to be behaving normally, but I figured > I would ask. > > The second, and far more disturbing thing is that any heavy accesses to the > filesystem (copying large files, scp-ing files mastering CDs, anything with > a lot of IO brings my machine to its knees. Case in point. When I started > this message, I was mastering a CD using xcdroast, which had called > mkisofs. Not only did the mastering take (I'm guessing here, since I didn't > note the time) about 10 minutes, the load average jumped, at one point, to > 8.23, and generally hovered around the 6-to-7 range. Copying large files > from filesystem to filesystem on the machine yields similar results. > Originally, I had the following configuration: > > hda 30GB HD > hdb 30GB HD > hdc DVD-ROM > hdd CD-RW > > A friend suggested moving the HD on hdb to the other channel, so now the > drives are on hda and hdc, the dvd is on hdb and the cdrw is on hdd. > > Can anyone give me any ideas as to why the machine gets beaten about so > much during IO operations and more importantly how can I minimize the > impact. > > Regards,