HSG80 specs

[Wim Van den Wyngaert]

Does anyone knows where I can find the specs of HSG80 ? I'm thinking of how many IO/sec, thruput etc and this also for dual controller config.

Wim

[Jan van den Ende]

Wim,

maybe you better ask that in the SAN forum...


Proost.

Have one on me.

Jan

[Uwe Zessin · Accepted solution]

Some data is in the specifications:
http://h18000.www1.hp.com/products/quickspecs/10545_div/10545_div.html

It says: 'over 24K IOPs per controller pair'. Max through a pair of controllers is about 50 to 60 MegaBytes, if I recall correctly. Max writes to a disk mirror I have seen is about 10 to 15 MegaBytes.

[Wim Van den Wyngaert]

Anyone an idea what the number of write IO/sec could be when the cache is full (sustained heavy load) ?

I see 5000 writes with blocksize 4 pages, thus 10 MB thruput.

Wim

[John Koska]

I believe http://h18006.www1.hp.com/support/techpubs/installation_guides/ek-sma34-an-a01.html will help you. View or download the PDF.

The application note speaks to the performance limits of various FC-Fabric components (Dual HSG-80 controllers performance of cached data and direct media in both IO/sec and MB/sec) for OpenVMS in Table 1.

:) jck

[Robert Atkinson]

Wim, we run dual HSG's with full mirrored cache, pretty much the setup you're talking about.

I've seen IO rates in 'MONI DISK' up to about 8000.

We currently have 4 shelves per pair, two in single bus mode, and two in split bus mode. Almost all of the bays are full (50+ disks), and we haven't seen the controllers flooding yet, even running 4 simultaneous data backups at the same time as doing a Dayend!

Rob.

[Wim Van den Wyngaert]

John, sorry but can't openb the PDF. Will try at home.

Robert,

We have peaks of 6000 WRITES and 1000 READS.
But all IO is done on 2 sites via FDDI shadowing, so there is an additional delay.

Did you look at the queue length ? And I don't mean asking 24 hours in TNG PA but asking an interval of 20 minutes or less. Then you see the real peaks (otherwise they are averaged in a bigger time interval, which is already 2 minutes in my test case).

Wim

[Robert Atkinson]

We have odd peaks at a queue length of 20, but most of the time it's between 0 and 2.

Interval is 5 minute samples.

Rob.

[Wim Van den Wyngaert]

With 5 minutes it is normal. We see only 1 peak in an interval of 2 minutes.

Wim

[Wim Van den Wyngaert]

As I read the data :

1 disk can do maximum 12K IO because it passes thru 1 controller (thus 50% of 24K). But since most IOs contain more than 1 block, the controller thruput of 20 MB/sec is limitting the number of IO's (e.g. to about 2500 when IO size is 8K).

Has anyone a dual HSG in which you see thruput of near 40MB/sec or 1 disk thruput near 20 MB ?

Is a fiberchannel switch a limiting thing ?

Wim