Hi all, I have to work with both systems an found some differences in the striping between the two kinds of LVM. I created a vg consisting of two disks on the HP-UX and on the linux system and a lv with the "-i 2 -I 64"-option. In the case of HP-UX the first LE points to the first PE on the first disk, the second LE points to the first PE of the second disk and so on. In case of Linux LVM the LEs corrospond to the PEs, there is no alternation and therefore no enhancement of performance because only one disk will be used at the same time. Where I am wrong? ciao Stephan HP-UX: --- Logical volumes --- LV Name /dev/vgmail/lvol1 VG Name /dev/vgmail LV Permission read/write LV Status available/syncd Mirror copies 0 Consistency Recovery MWC Schedule striped LV Size (Mbytes) 4096 Current LE 1024 Allocated PE 1024 Stripes 2 Stripe Size (Kbytes) 64 Bad block NONE Allocation strict IO Timeout (Seconds) default --- Distribution of logical volume --- PV Name LE on PV PE on PV /dev/dsk/c4t6d1 512 512 /dev/dsk/c6t6d2 512 512 --- Logical extents --- LE PV1 PE1 Status 1 00000 /dev/dsk/c4t6d1 00000 current 00001 /dev/dsk/c6t6d2 00000 current 00002 /dev/dsk/c4t6d1 00001 current 00003 /dev/dsk/c6t6d2 00001 current 00004 /dev/dsk/c4t6d1 00002 current 00005 /dev/dsk/c6t6d2 00002 current 00006 /dev/dsk/c4t6d1 00003 current 00007 /dev/dsk/c6t6d2 00003 current ... Linux: --- Logical volume --- LV Name /dev/vg00/lvol1 VG Name vg00 LV Write Access read/write LV Status available LV # 1 # open 1 LV Size 4 GB Current LE 1024 Allocated LE 1024 Stripes 2 Stripe size (KByte) 64 Allocation next free Read ahead sectors 120 Block device 58:0 --- Distribution of logical volume on 2 physical volumes --- PV Name PE on PV reads writes /dev/sdb1 512 1536487 1472056 /dev/sdc1 512 1535960 1472315 --- logical volume i/o statistic --- 3072447 reads 2944371 writes --- Logical extents --- LE PV PE reads writes 00000 /dev/sdb1 00000 0 1008 00001 /dev/sdb1 00001 0 1024 00002 /dev/sdb1 00002 0 590 00003 /dev/sdb1 00003 0 848 00004 /dev/sdb1 00004 0 16 00005 /dev/sdb1 00005 0 0 00006 /dev/sdb1 00006 272 2594 -- LDS Brandenburg Dr. Stephan Hendl fon: +49-(0)331-39 471 fax: +49-(0)331-27548 1187 EMail: stephan.hendl@lds.brandenburg.de
