Barry,
I know of only one Amisys customer using RAID-5 in production. There may
be others, but I only know of the one. They are definitely disk bound but
they came up that way so they don't have experience on how good HP 3000
disk I/O can really get.
There are only a few choices for overall disk protection:
1. Mirrored Disk/iX for user volume sets and (possibly) disk arrays for SVS.
2. Model 10/20 disk arrays for the complete disk environment.
3. EMC (RAID-1 for the SVS and either RAID-1 or RAID-5 for user volume sets)
4. SSA.
5. NetBase/SharePlex full system redundancy.
(You could probably mix and match successfully)
How can you choose which approach?? It depends...
Some of the plusses and minuses:
1. Mirrored Disk/iX - software mirroring (plus and minus), mirror only
user volume sets (minus), two disk mechanisms to choose from when reading
(major plus), two disk mechanisms to write to (mild minus)
2. Disk arrays - fairly expensive (minus), lousy RAID-5 performance (an
oxymoron and a minus), less capable than brethren devices in the HP-UX
world (minus), not particularly suited to large environments (minus)
3. EMC - most expensive solution (big minus), excellent technical support
organization (plus), pain-in-the-ass sales force (definite minus), HP's
chosen technology for 100gb+ environment (plus or minus depending on your
perspective), heterogeneous (BIG plus), best situated for very large scale
environments in terms of scalability (plus)
4. SSA - relatively affordable (big plus), not officially supported by HP
(but they may be somewhat malleable) (minus), not a lot of HP 3000
installations (minus), their presence in the market may exert positive
pressure on EMC (plus)
5. NetBase/SharePlex - excellent wide-availability product (big plus),
specific for MPE (plus), expensive (minus), somewhat complex to maintain
(minus), creates reporting system (excellent for Amisys customers in
particular) (big plus)
In general, for a straight disk availability perspective, I generally
recommend Mirrored Disk/iX. It has the best performance characteristics of
all available choices (though some would argue with that). It is also
fairly bulletproof and requires very little post-installation maintainance.
If you have a heterogeneous environment AND you require high disk
availability for all platforms AND/OR you have more than 100gb (before
mirroring), (and money is available) EMC may be the best choice.
You will take a performance hit installing anybody's RAID-5 solution over
JBOD (Just-a-Bunch-Of-Disk). The question will be, is it worth it? Only
you can answer that but generally, it isn't, particularly in such an
I/O-intensive environment as Amisys.
Hope this helps.
Bill Lancaster
At 02:11 PM 9/1/98 -0600, [log in to unmask] wrote:
>The director of my area asked me to check into Amisys Performance when using
>Raid 5 and Disk Mirroring. Currently we have no high availability option
and
>he asked me to check into the possibilities. I was wondering how many (if
any)
>Amisys customers use RAID-5 or Disk Mirroring. I was also wondering about
>performance improvement or degradation. I am also assuming that with
RAID-5
>would cost less since we would not need as many drives.
>
>BTW, I do realize that we can not software mirror the system volume set
>(MPEXL_SYSTEM_VOLUME_SET).
>
>Thanks in advance!
>
>
>
>------------------------------------------------------------------
>Barry Durand, Systems Engineer II, [log in to unmask]
>"These are my opinions, not necessarily the ones of my employer"
>------------------------------------------------------------------
>
>
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