[linux-lvm] hardware raid5 and lvm "recipe"

[linux-lvm] hardware raid5 and lvm "recipe"

[Amir Mistric]

[-- Attachment #1: Type: text/plain, Size: 680 bytes --]

Hi

 

We are contemplating to start using RHEL v4 in our enterprise.

Most of our servers have a hardware RAID.

 

The server we are using for a RHEL 4 trial install has 4x36GB SCSI drives
configured using RAID 5.

Of course, we also want to use LVM.

 

 

Can someone please suggest what would be the best "layout"/"recipe"
considering the configuration I described?

Using "automatically" partitioning during install RHEL suggests: 

/boot and swap outside LVM and the rest of space in LVM mounted under / file
system.

 

Is this sufficient layout for maximum flexibility? Should I create other
logical volumes and file systems?

 

 

Any tips are appreciated

 

Amir

 


[-- Attachment #2: Type: text/html, Size: 4235 bytes --]

Re: [linux-lvm] hardware raid5 and lvm "recipe"

[Sam Vilain]

Amir Mistric wrote:
> We are contemplating to start using RHEL v4 in our enterprise.
> Most of our servers have a hardware RAID.
> The server we are using for a RHEL 4 trial install has 4x36GB SCSI 
> drives configured using RAID 5.
> Of course, we also want to use LVM.
> Can someone please suggest what would be the best �layout�/�recipe� 
> considering the configuration I described?
> Using �automatically� partitioning during install RHEL suggests:
> /boot and swap outside LVM and the rest of space in LVM mounted under / 
> file system.
> Is this sufficient layout for maximum flexibility? Should I create other 
> logical volumes and file systems?

Seems like a good enough policy.  An alternative is to have a larger
root, so that you can do LVM diagnostics without using a boot CD.  But
using a standard vendor configuration means that you're going to surprise
fewer admins that come along.

> Any tips are appreciated

Here's a tip... simulate a failure and make sure that you can detect it.
If you've got pluggable disks, then quiesce the system and unplug one.
Never unplug an active disk, of course.
-- 
Sam Vilain, sam /\T vilain |><>T net, PGP key ID: 0x05B52F13
(include my PGP key ID in personal replies to avoid spam filtering)

[linux-lvm] Fixed. But what are PV# and Cur LV in pvdata?

[oliver]

After spending hours trying to figure out what values to put where, all 
the data seems to be reconstructed. I ran a reiserfsck on all partitions 
and everything was Okay.

I'm stuck however with the PV# and Cur LV reported by pvdata. I kinda 
'guessed' them. The PV# was easyer to guess I think, as PV#'s apear to 
be unique. (comparing between my two LVM setups they both where, with 
the exception of the missing PV# of course). However the Cur LV i wans't 
sure what to put there. I now used a Unique identifier for it. E.g. On 
the other two it said 1 resp. 3 so I took 2 for my missing one. The rest 
I just copied the values from the other two PV structures. The PV Size I 
did some math on, Total - 2others, converted to hex, swapped bytes and 
put in same location as the other two had them. The other 'size' looking 
element was coincidently PV Size+1, so i did that also.

Also it appears to me that in lvm2 that doesn't even matter anyhow.

Anyway, If any of you have any clue what the PV# and Cur LV are, please, 
let me know.

I hope this post will help someone out there reading some archives some 
time : )

oliver

Re: [linux-lvm] hardware raid5 and lvm "recipe"

[Michael T. Babcock]

Sam Vilain wrote:

> Seems like a good enough policy.  An alternative is to have a larger
> root, so that you can do LVM diagnostics without using a boot CD.  But
> using a standard vendor configuration means that you're going to surprise
> fewer admins that come along.


We use a 4GB root partition, 2GB swap partition and then the rest is a 
PV for LVM2.
-- 
Michael T. Babcock