Very Computer

It has been pushed and recommended by the company quoting us, that we opt
for RAID 5, which, up until right now, I've been happy with (we are in need
for an improvement back-up strategy over our current one hard drive + one
tape drive solution).

However, looking on the Top Tips on PROGRESS' knowledge Center today, tip 14
says:

------------
14. DO NOT USE RAID 5.

You are highly likely to achieve a 45 percent performance loss in normal
operations and more when doing maintenance or recovery operations.
------------

So, how many people are actually running SCO/PROGRESS on RAID 5 out there?
Should I seriously reconsider RAID 5?

Our server will likely be upgraded from a Pentium-II 333MHz, 384mb machine
to a Pentium-4 1.7GHz 512mb system... so should we really be concerned about
RAID 5 hogging all the system's resources? Bearing in mind we only have 15
users, a 2.7gb database and fairly low transactions.

Thanks all.

Elliot

Quote:> We may soon be deciding on a new server for our 15 user PROGRESS v8.2c
> database (SCO UNIX Enterprise OpenServer v5.0.4 - likely being
> upgraded to v5.0.7).

> It has been pushed and recommended by the company quoting us, that we
> opt for RAID 5, which, up until right now, I've been happy with (we
> are in need for an improvement back-up strategy over our current one
> hard drive + one tape drive solution).

> However, looking on the Top Tips on PROGRESS' knowledge Center today,
> tip 14 says:

> ------------
> 14. DO NOT USE RAID 5.

> You are highly likely to achieve a 45 percent performance loss in
> normal operations and more when doing maintenance or recovery
> operations. ------------

> So, how many people are actually running SCO/PROGRESS on RAID 5 out
> there? Should I seriously reconsider RAID 5?

> Our server will likely be upgraded from a Pentium-II 333MHz, 384mb
> machine to a Pentium-4 1.7GHz 512mb system... so should we really be
> concerned about RAID 5 hogging all the system's resources? Bearing in
> mind we only have 15 users, a 2.7gb database and fairly low
> transactions.

> Thanks all.

> Elliot

It is not the day to day running where RAID 5 will drop you in the brown
stuff, but if you have to do a dump & load in a hurry (and it happens,
trust me)..

Kevin

As Kevin points out, dump & load (specifically load) will be the place
where you notice this most.

--
========================================================
Stephen *iuk               stephen at sentai dot com
Sentai Software Corporation

RAID 0+1 is what we use very effectively.

Murray

Quote:> '> We may soon be deciding on a new server for our 15 user PROGRESS v8.2c
> database (SCO UNIX Enterprise OpenServer v5.0.4 - likely being
> upgraded to
> v5.0.7).

> It has been pushed and recommended by the company quoting us, that we
> opt
> for RAID 5, which, up until right now, I've been happy with (we are
> in need
> for an improvement back-up strategy over our current one hard drive +
> one
> tape drive solution).

> However, looking on the Top Tips on PROGRESS' knowledge Center today,
> tip 14
> says:

> ------------
> 14. DO NOT USE RAID 5.

> You are highly likely to achieve a 45 percent performance loss in
> normal
> operations and more when doing maintenance or recovery operations.
> ------------

> So, how many people are actually running SCO/PROGRESS on RAID 5 out
> there?
> Should I seriously reconsider RAID 5?

> Our server will likely be upgraded from a Pentium-II 333MHz, 384mb
> machine
> to a Pentium-4 1.7GHz 512mb system... so should we really be
> concerned about
> RAID 5 hogging all the system's resources? Bearing in mind we only
> have 15
> users, a 2.7gb database and fairly low transactions.

> Thanks all.

> Elliot

Practical realism stepping in here!

Having run a 250GB v8.3 database on a small box with a BIG RAID5 array
I can say that it will work. No doubt - no question.

The reason we ran this database on this array was that it was ENTIRELY
STATIC. It never changed. We didn't dump and reload it - we restored
from backup. We did no maintenance to this database.

Under this environment we were happy to have RAID5.

You mention taht the server is getting a substantial upgrade, but not
whether or not the disk subsystem is affected.

If you go from RAID5 on 4.3GB 7200RPM drives to RAID5 on 36GB 15000RPM
drives, then the new disks will perform better than the old.

If you splurge and go to 18GB 10000RPM drives and do RAID0+1 or RAID1
you will get a bigger bang for your buck.

The only downside on this is that you have more spindles and that
increases the chance of any 1 spindle being failed at any point (based
on MTBF and statistics!).

RAID1 rebuilding arrays is usually a fairly short term process and
affects the exact mirror disk.
RAID5 rebuilding arrays affects every disk in the set
RAID0+1 rebuilding also affects every disk in the set.

I would not ever advocate the use of RAID5 in a production database
where data is changing. However, under the circumstances you mention,
price sensitiity is probably more the concern than the ultimate bang
for buck. However - Try and get RAID1....

Looking at your config - You need 3 disks to have RAID5

You can probably do RAID1 with 2x36GB drives...!

Brian

Brian

Brian

Brian

Brian

Quote:> If memory serves, due to the inherent nature of the way databases
> work, there is a chance that you could corrupt your entire database by
> running on RAID5. Unfortunately, I can't find the supporting
> documentation for this. However if you are considering running RAID5,
> I would confirm with Progress wether this is true or not.

> Brian

Kevin