From mboxrd@z Thu Jan 1 00:00:00 1970 Message-Id: Date: Fri, 14 Sep 2001 08:08:22 +0200 From: "Stephan Hendl" Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Subject: [linux-lvm] diff. in striping between HP-UX and Linux LVM Sender: linux-lvm-admin@sistina.com Errors-To: linux-lvm-admin@sistina.com Reply-To: linux-lvm@sistina.com List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: List-Id: Content-Type: text/plain; charset="us-ascii" To: "<" 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.=20 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 =20 -- LDS Brandenburg Dr. Stephan Hendl fon: +49-(0)331-39 471 fax: +49-(0)331-27548 1187 EMail: stephan.hendl@lds.brandenburg.de