topic Re: Volume Mirroring in Operating System - HP-UX

Volume Mirroring

Qcheck — Mon, 26 Mar 2007 07:28:15 GMT

Good morning All,

When I tried to check the server whether every file system has been mounted or not with the following command, it doesn't show anything? Any ideas????

# lvdisplay /dev/vg00/lvol* | grep mirror

Thanks

Re: Volume Mirroring

Pete Randall — Mon, 26 Mar 2007 07:30:05 GMT

Try

# lvdisplay /dev/vg00/lvol* | grep -i mirror

Pete

Re: Volume Mirroring

Qcheck — Mon, 26 Mar 2007 07:32:06 GMT

Never mind everyone, I should have used "grep -i mirror", it worked....Monday morning I was so paniced when I couldn't see any mirrors. Because cat /etc/lvmtab, doesn't show anything except one line. Is that normal???

Re: Volume Mirroring

Qcheck — Mon, 26 Mar 2007 07:33:42 GMT

Hi Pete,

Thank you....I got it....

Re: Volume Mirroring

MarkSyder — Mon, 26 Mar 2007 07:37:24 GMT

He knows you got it, but he still deserves points for giving you the right answer!

Mark Syder (like the drink but spelt different)

Re: Volume Mirroring

TwoProc — Mon, 26 Mar 2007 07:42:47 GMT

lvdisplay -v /dev/vg00/lvolxxxx
If you're mirrored, on each line you'll see:
A: the logical extent number
B: The first device of the mirror followed by the PE on that disk, followed its state (current/stale/etc).
C) The second device of the mirror followed by the PE on that disk, followed its state (current/stale/etc).

If you've got only four columns of data for each logical extent, your lv is not mirrored. If you've got 7 columns here your lv is mirrored.

Re: Volume Mirroring

Patrick Wallek — Mon, 26 Mar 2007 08:28:55 GMT

The /etc/lvmtab is a binary file, so cat will not show anything. To look at the lvmtab file you need to use the 'strings' command.

# strings /etc/lvmtab

You will still see some strange characters, but don't be alarmed.

The lvmtab file will not show what you want either though. There's no information about mirrors in the lvmtab file.

Re: Volume Mirroring

Qcheck — Mon, 26 Mar 2007 08:32:39 GMT

Hi John,

How and where can I check the columns to find if I have four or seven columns????

How abt /etc/lvmtab??I just want to know if my /etc/lvmtab is fine....

And Mark! You are right...and I am very generous in giving points.....so in that way, should be lucky to answer my questions...hahahaha...;)

Thank you all...

Re: Volume Mirroring

Qcheck — Mon, 26 Mar 2007 08:46:12 GMT

Thank you Pat...

U all got points now....

Re: Volume Mirroring

TwoProc — Tue, 27 Mar 2007 09:51:32 GMT

when you do the lvdisplay -v /dev/vgxx/lvolxxx

You'll see a list of the logical extents, its the very long display after the "introductory details".

A snippet of mirrored extents look like:

00241 /dev/dsk/c0t6d0 01816 current /dev/dsk/c10t6d0 00816 current
00242 /dev/dsk/c0t6d0 01817 current /dev/dsk/c10t6d0 00817 current
00243 /dev/dsk/c0t6d0 01818 current /dev/dsk/c10t6d0 00818 current
00244 /dev/dsk/c0t6d0 01819 current /dev/dsk/c10t6d0 00819 current
00245 /dev/dsk/c0t6d0 01820 current /dev/dsk/c10t6d0 00820 current
00246 /dev/dsk/c0t6d0 01821 current /dev/dsk/c10t6d0 00821 current
00247 /dev/dsk/c0t6d0 01822 current /dev/dsk/c10t6d0 00822 current
00248 /dev/dsk/c0t6d0 01823 current /dev/dsk/c10t6d0 00823 current
00249 /dev/dsk/c0t6d0 01824 current /dev/dsk/c10t6d0 00824 current

A snippet of unmirrored extents look like:

00241 /dev/dsk/c0t6d0 01816 current
00242 /dev/dsk/c0t6d0 01817 current
00243 /dev/dsk/c0t6d0 01818 current
00244 /dev/dsk/c0t6d0 01819 current
00245 /dev/dsk/c0t6d0 01820 current
00246 /dev/dsk/c0t6d0 01821 current
00247 /dev/dsk/c0t6d0 01822 current
00248 /dev/dsk/c0t6d0 01823 current
00249 /dev/dsk/c0t6d0 01824 current

Re: Volume Mirroring

Jollyjet — Wed, 28 Mar 2007 00:58:32 GMT

Hi,
to check all the file system is mounted you need to follow on bdf output

lvdisplay /dev/vg00/lvol* | grep mirror

the above one will tell you whether it is mirrored or not

Re: Volume Mirroring

Qcheck — Wed, 28 Mar 2007 09:44:17 GMT

Hi John and Jolly,

Thank you for the information and I really appreciate all your time. I am clear now and all my filesystems are mirrored.

Thanks again