I have RAID-1 and datastorage on LVM2 (converted from LVM1 format). When using
"iostat", I'm able to see IO statistic for md0, md1, every hd[a-z] but not whole
LVM evn there is active and mounted LV on it. When trying to monitor only LVM
device, there is zero activity even there is /sys/block/dm-0 (with zeroes).
I'm able to see strange values for md0 and md1 too. md0 has only 2/3 of hda and
hdc (even they are dedicated for RAID-1 [md0 and md1]):
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
hda 1,33 0,00 15,95 0 48
hdc 1,33 0,00 15,95 0 48
md0 1,33 0,00 10,63 0 32
md1 0,00 0,00 0,00 0 0
Expected result: Ability to monitor IO in systemon all devices (RHEL4b2).
hi - can you attach a copy of your /proc/diskstats?
Created attachment 108913 [details]
Back to assigned.
The kernel does not report partition information for lvm devices in
/proc/diskstats. Sysstat cannot report information it doesn't have.
I'll push this to the attention of the kernel group.
*** This bug has been marked as a duplicate of 168483 ***