Would you still be able f.e. to write patches for the HSG80 ?
No, sorry. I don't have the knowledge (any more), nor the development tools, nor the source code. When I was doing that kind of thing, I worked on version builds, not patches.
In 1997/98, I was part of an "OEM Firmware" team that made customer-custom builds for large customers such as Seimens-Nixdorf (SNI). I still have a list of those custom features. Here are some of the changes that were requested by SNI:
SHOW_BATTERY_STATE - Display the state of the battery when the 'cache_ups' switch is ON.
BAD_BATTERY_EMU_ALARM - Turn on the EMU alarm when the battery is FAILED while cache_ups is ON.
MULTI_BUS_INQUIRY - When in multi-bus failover, and the Unit is 'inop', do not show Unit as 'accessible' in the inquiry data.
Etc.
Reading the doc today brings back a lot of memories... In those days, SNI was our biggest customer for custom FW builds. I remember our contact at SNI was a fellow named Juergen.
There has been a limitation in max. scsi drive size (74 or 146 gig) and also in max array size around 1 terra if i remember correctly.
And do you eventually remember how much extra space has been reserved by the different drive firmwares ?
If i remember it correctly the useable size of the Compaq/HP scsi drives was a little bit smaller than the ones with the standard factory firmware,
and one has not been able to use those drives in the array bc of more reserve blocks to allocate by the original Compaq/HP drives...
I don't know/remember much about that. I can say that our team did not do anything related to drive FW - only things that were available via SCSI Mode Pages. But here is feature that we considered doing in the Spring of 1998. I believe we never implemented it, and a few months later we quit doing custom FW builds:
BIGLUN_SUPPORT
Function: Make 2 or more units appear to be one big virtual unit, from the host’s view. For example, if there is a 2GB unit and a 4GB unit configured in the controller, then the host would see the first unit with a 6GB size, and the second unit with a 0GB size.
Purpose: The controllers currently have a limitation on the maximum size for a single LUN. The limitation comes from 24 drives (max) in a Stripeset, or 14 drives (max) in a RAIDset. This option would make it possible to create a single virtual LUN that was more than twice the size (about 1.2 terabytes) of the current largest LUN (about 500 GB).
Hardware Platforms: SC6650, FC6650
Pete