topic Re: checking striping in linux in Operating System - Linux

checking striping in linux

laiju.c.babu — Mon, 26 Mar 2012 12:08:49 GMT

Hi Guys,

I am using RHEL 5.6 and i am using LVM . I want to know how can i check whether a lv is striped or not in RHEL 5.6.

Commonly in HPUX i can get this detail from lvdisplay -v . but in this case i am not able to get this detail ,

Could anyone please help me on this ....

Regards

Laiju.C.Babu

Re: checking striping in linux

Matti_Kurkela — Mon, 26 Mar 2012 13:29:06 GMT

Try "lvdisplay -m" instead.

In HP-UX, "lvdisplay -v" will display each logical extent on a separate line.

In Linux LVM2 (= all 2.6.* kernels) "lvdisplay -m" will display a more condensed listing. Here's an example:

# lvdisplay -m /dev/vg00/home
  --- Logical volume ---
  LV Name                /dev/vg00/home
  VG Name                vg00
  LV UUID                9v3cKt-40dV-vpWa-NNVv-ptZk-ZVc8-ZBWlxE
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                100.00 GiB
  Current LE             25600
  Segments               2
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     6144
  Block device           253:3
   
  --- Segments ---
  Logical extent 0 to 20921:
    Type                linear
    Physical volume     /dev/dm-0
    Physical extents    15616 to 36537
   
  Logical extent 20922 to 25599:
    Type                linear
    Physical volume     /dev/dm-0
    Physical extents    2560 to 7237

This is a LV that has been extended once after creation, so it exists as two linear mappings.

The key word here is "linear": it is the default and means "not striped".

I don't have any LVM-striped LVs configured (we usually let the big SAN storage system do the striping), but with a striped LV, I think the "Type" field would say "striped" instead.

Re: checking striping in linux

laiju.c.babu — Mon, 26 Mar 2012 13:47:32 GMT

Hi MK,

Thanks for the reply ,,

I got some more commands to get this information

lvs -v --segments

lvs -a -o +devices

Regards

Laiju C Babu