[linux-lvm] lvm mirror read performance, no load balance with PV ?

[Sascha Thomas Spreitzer]

Hello mailing list,

I currently sensed that LVM2 is not load balancing reads of mirrored
LV's form their corresponding PV.

PV1     PV2
LV        LV'
IO=0    IO=90MB/s

[~]# lvm version
  LVM version:     2.02.39 (2008-06-27)
  Library version: 1.02.27 (2008-06-25)
  Driver version:  4.14.0

Distribution is Fedora 10, updated.

Is this normal behaviour, or did a make a big mistake in my configuration?

FYI:

[~]# pvs -o+lv_name,lv_size,lv_attr
  PV         VG         Fmt  Attr PSize   PFree LV                LSize   Attr
  /dev/sda2  VolGroup00 lvm2 a-   145,22G 4,97G [lvroot_mlog]      32,00M lwi-ao
  /dev/sda2  VolGroup00 lvm2 a-   145,22G 4,97G [lvhome_mlog]      32,00M lwi-ao
  /dev/sda2  VolGroup00 lvm2 a-   145,22G 4,97G lvdata            285,50G -wi-ao
  /dev/sda2  VolGroup00 lvm2 a-   145,22G 4,97G [lvswap_mlog]      32,00M lwi-ao
  /dev/sda2  VolGroup00 lvm2 a-   145,22G 4,97G                        0
  /dev/sda3  VolGroup00 lvm2 a-   553,28G    0  [lvswap_mimage_1]   5,03G iwi-ao
  /dev/sda3  VolGroup00 lvm2 a-   553,28G    0  [lvroot_mimage_1]  15,00G iwi-ao
  /dev/sda3  VolGroup00 lvm2 a-   553,28G    0  [lvhome_mimage_1] 533,25G iwi-ao
  /dev/sdb1  VolGroup00 lvm2 a-   698,62G    0  [lvswap_mimage_0]   5,03G iwi-ao
  /dev/sdb1  VolGroup00 lvm2 a-   698,62G    0  [lvroot_mimage_0]  15,00G iwi-ao
  /dev/sdb1  VolGroup00 lvm2 a-   698,62G    0  [lvhome_mimage_0] 533,25G iwi-ao
  /dev/sdb1  VolGroup00 lvm2 a-   698,62G    0  lvdata            285,50G -wi-ao

-- 
Mit freundlichen Grüßen, / with kind regards,
Sascha Thomas Spreitzer
http://spreitzer.name/