Dear Subba Rao,

I am being interviewed for some jobs where they are asking for Sun Solaris experience. For a long time I have been a *nix user but did not pay too much attention to the System V vs the BSD camps. I know Solaris falls into the BSD camp. How different is it from Linux? My experience is in System V, AIX and Linux (some HP/UX). Having this experience, what areas of Solaris should I focus on to get my foot in the door.

If by Solaris you mean Solaris 2 or SunOS 5, or later, then you're talking a Unix which was re-written from the ground up, pretty much rejecting the entire codebase which went into their super-popular SunOS 4.x (4.1.3 was the last that I remember).

SunOS was strongly BSD-derived. Solaris was the product of the OSF versus UI (Unix International) wars in the early nineties, where AT&T and Sun were the two biggest partners to back UI, and attempt to bring in a new age Unix kernel combining the best of the old SVR2 and BSD. I think Sun called their first version of Solaris "SunOS 5.x", to indicate a sort of continuity, but actually there was none. And users were pretty much forced to shift to Solaris, because Sun stopped porting SunOS on new versions of hardware pretty soon after Solaris was released, causing a lot of resentment and heartburn, specially because Solaris had serious bugs in core areas (e.g. VM) at that time. Oh yes, Sun can run with the hare and hunt with the Redmond hound like the best of them. :)

Therefore Solaris, like other close implementations of the UI design, has a strong SVR2-ish flavour.... in fact it's AT&T SVR4, I think. Of course, the Solaris of today has moved on ahead a lot since the SVR4 days of ten years ago.

One of the "features" of UI (e.g. Solaris) used to be that you could set env vars and make various utilities (like "ps", "ls", etc, IIRC) behave like either the BSD flavour or the SVR4 flavour. I remember UI Unix coming with two sets of runtime shared libraries even. Therefore, on the same system with the same binary distro of shell utilities, different users could get different behaviour in the little details. Of course low-level sysadm was very SVR4-specific, and didn't have this split personality. Therefore, I don't think a direct mapping from BSD or Linux will help much to teach you Solaris.

I suggest that given your strong multi-flavour Unix background, you should just get a book which gives you specific "howto"-type commands and tools descriptions for Sun Solaris... maybe one of those "Master Sun Solaris vX.Y in 21 days!" things... and just read it. I feel you'll just need to read up on specific external details.

(There are very interesting conceptual issues in Solaris internals, like their implementations of LWP and SMP support, etc, but those can probably come after you've landed your job and begin working on Solaris.:))

Sorry if my inputs were more of background material than direct roadmaps for your requirements. And best wishes for the interviews.

regards, Shuvam