Internal disks layout

[Vassily Gorbounov]

Dear colleagues,

I need an advice concerning layout of the root volume group.
I have an HP9000 server in the following configuration:

K370 server
4 CPU 8200
2 GB memory
4 by 2 GB internal -disks on the same internal controller (fast-wide AFAIK)
AutoRAID 12H external array with 8 by 9GB and 4 by 18 GB.

The question is about internal drives - how to use them. They are quite old - dated I believe approx 1997 year and could not be replaced with the ones of bigger capacity and performance.
Our main requirements are (as usual) - reliability (a must) and performance (strong wish).
Now we have placed all four internal drives into one volume group and mirrored them one-to-one. So we have 4 GB of space in volume group although performance is far from desired.

I see three variants these disks usage:

1. Do not use them at all - instead use RAID as boot drive

2. Use two disks as 2GB swap drives each and two other disks - put in the mirror (we use MirrorDisk/UX now) so if any drive fails it does no harm whilst providing fair performance. Then I'll put single file system on the whole disk and mount RAID file systems beneath.

3. Current scheme - 4 disks in VG then mirror 1st to 3rd and 2nd to 4th

Which of the schemes would you advise? Or may be you'll propose something better

Regards,
Vassily

[harry d brown jr]

If they are that old (and that is not really old), they should be depreciated by now, so go for some larger internal disks, which will (should) have better performance than the 12H. that's by $0.00002 (tax man got me) worth.


live free or die
harry

[Craig Rants]

Vassily,
I would not go with any of your proposals, no offense. Personally I would use two internal disks for the O/S (no way you want vg00 just on 2GB) and then mirror those two disks to the autoraid. Then I would use the other two internals and create and alternate vg00, this is more complicated, but you could use this vg to boot from just in case your had problems with the autoraid. Sounds like overkill, but with the environment you described that will give you the best opportunity for keeping a system up.

Just my opinion,
C

[James R. Ferguson]

Hi Vassily:

If you just can't find the money to replace these drives with bigger ones, I'd opt for leaving your current arrangement. As you say, they are old, and therefore I'd sure want the mirror protection!

Ideally, one would like a single physical disk to comprise vg00; a mirror of every logical volume on it (including primary swap); and secondary swap (if/as necessary) on another volume group.

Christmas is coming... ;-)

Regards!

...JRF...

[harry d brown jr]

Don't do option 2. You do not want a single filesystem (/) with another VG for the other mount points - that would be almost insane.

As for option 1, if you ain't using them LOSE them. If they are running they are running - if one fails and starts spewing garbage on the scsi, it will ruin your day.

As for option 3. Well I'd refer back to my original post about replacing them.


live free or die
harry

[Roger Baptiste]

Ideally, i would prefer two new internal disks of say 9gb, which would replace the
4*2gb ones. But, life is not that simple , so--

i would vote for option 3.
Let the default remain as it is. If you are running short of space (which you will eventually) on VG00, then
you would have to consider
option 1 i.e. moving everything to RAID. Not the best of things to do, but better than cramming and trying to manage everything on 2gb disks. Well, if anything happens, you can use the line to the management " i told you so..!"

-raj

[Vassily Gorbounov]

Thanks for everybody,
I promise to assign points tomorrow in the morning when I'm at work and will have a time to think it over (now it's a midnight in Moscow).

Just some details:
1. It's not a matter of money for us to buy new disks - it just seemd to me that there are none of them on the market. Seems I was wrong. Then it must be a good option to replace 2GB disks with 9 GB disks.

2. Now we have the following scheme:
System Files + Swap - on internal drives
Application Files - on autoraid

3. Speaking of the current configuration - I don't like it in terms of performance and would stick to it only as a last resort

4. To Harry D Brown Jr - why do you think that single filesystem + mounted autoraid is insane? It sounds pretty normal for me (although I never use such configuration) to have all folders like /var, /usr, /opt under the same filesystem and application directories mounted as /app1, /app2 etc.

5. It's not a problem for us to manage space on vg00, we rather have our application directories expanding rapidly

Thanks for everybody for your valuable answers and still looking for more.

Vassily

[Craig Rants]

Vassily,
If it is not a problem to get new disks, by all means get at least two new 9GB disks, install the O/S on one and mirror to the other. Put all the rest of your application data on the Autoraid.

Good Luck,
C