Grant Zhang: Snapshot of life

In case you haven't noticed, we've integrated a nice little feature into open Solaris Build 97: a more user-friendly [s]sd-config-list. The detailed feature description can be found in PSARC 2008/465. 

What is sd-config-list?

sd-config-list has been a private property in [s]sd.conf for [s]sd driver since 1999. The original intention for this property was just for internal development/field diagnosis, as the name "private" suggests. As time flies, many people in/outside Sun started using it to tune its disk systems. Doing a google search on sd-config-list gives you a long list of storage vendors who tell you how to use sd-config-list on their disk storage, like this, this and this.

But using sd-config-list is painful and error prone. Here is an example:

  ssd-config-list= "SUN     T4", "t4-data";

  t4-data=1,0x20000,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1;

So what are the changes?

A picture is worth a thousand words and an example should counts at least five hundreds. The new sd-config-list looks like this:

  ssd-config-list =

    "SUN     T4", "delay-busy:600, retries-timeout:6",

    "SUN     StorEdge_3510", "retries-timeout:3";

One more thing, the sd-retry-count tunable is back to Solaris. Of course, you have to use sd-config-list to configure sd-retry-count(now called "retries-timeout", the retries to perform on an IO timeout) on a per device type basis.

Future works?

There are two fronts of future works:

• Providing generic interfaces in Solaris libnvpair to convert between nvlist and JSON text


• Adopting more driver properties to use the JSON format. A quick target would be tape-config-list in st.conf.
  

Kudos to Chris and Nikko who make this happen!