different size disks in mirrored stripe?

[Matt Harrell]

Here's the scenario. HP D 9000/879 with HP-UX 11.0. I have an external drive array that will have 4, 4 GB disks, and 4, 9 GB disks. I'm wondering if I will be able to do an extent-based mirrored stripe with all of these disks. Based on the man page for lvcreate, it seems like it should work, but I'm new to much of this, and I'm not quite certain. The disks will contain a Progress database and one online backup copy, and I'm also curious if anyone has any thoughts on whether an extent-based mirrored stripe is the best way to go?

[Paula J Frazer-Campbell]

Hi Matt

Yes it will work

Split your disks to :-

2 x4gig and 2 x 9 gig in one half of the mirror and them mirror the other disks to it.

Paula

[A. Clay Stephenson]

Hi:

Yes that will work. Do as Paula says but when you create your volume group make sure that you start with the larger disks so that enough PE's are allocated.

[Joseph C. Denman]

Matt,

What type of array are you using? If you are using the 12h autoraid, the raid will handle the striping for you. However, for performance, you will want you stripe the data across both controllers if you have 2.

...jcd...

[Sridhar Bhaskarla]

Matt,


Will it work "yes". You can follow as per Paula's.

Best way? The answer is "it depends".

It depends on the type of transactions your database does.

If it is going to generate large sequential IOs, extent level striping may be ok. For smaller IOs, it doesn't matter. In most of the cases regular lvm striping improves the performance. Reads may improve a bit due to mirrors in your case.

-Sri

[harry d brown jr · Accepted solution]

Matt,

Read:
http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0xa16c1cc6003bd6118fff0090279cd0f9,00.html

and
http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x0437af48a9e5d5118ff40090279cd0f9,00.html

live free or die
harry

[Matt Harrell]

Thanks. It sounds like I'd be better off with just strict mirroring.