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- Path: sparky!uunet!cs.utexas.edu!torn!utgpu!utorvm!ryevm.ryerson.ca!syst8103
- Organization: Ryerson Polytechnical Institute
- Distribution: na
- Date: Friday, 22 Jan 1993 10:25:19 EST
- From: Ron Wigmore <SYST8103@RyeVm.Ryerson.Ca>
- Message-ID: <93022.102519SYST8103@RyeVm.Ryerson.Ca>
- Newsgroups: comp.unix.aix
- Subject: Another Newbie Asks A Question ...
- Lines: 42
-
-
- We just had three RS6K boxes installed on our computer floor. I have been
- reading over a few of the manuals, checking things, etc., and I came upon
- the part which says that "the default installation option is to spread
- rootvg over all available disks". I checked and, yes, that is the way
- it was installed.
-
- Most of my experience is on mainframes and we would never put the system
- components on each and every disk, since losing any one disk means your
- system crashes. We tend to have 'system' disks, 'application' disks, and
- 'user' disks. This way, if you lose a disk, the chances are the majority
- of the users can continue 'business as usual'.
-
- Are RS6K boxes so *radically* different that the "mainframe way" is not
- a necessary approach? We only have 6 hdisks, so I do not have a lot of
- flexibility when it comes to 'spreading things around'. Would it not be
- wiser/safer/better to have hdisks 1, 3, 5 as 'system' disks and merge the
- user/application stuff on hdisks 2, 4, and 6?
-
- Without getting into I/O contention concerns - at this point in time - I
- think this would give me a 50% chance of my system crashing if we lost
- a disk, versus the 100% if we used the 'default way'. Losing a system
- disk gets equated to being "shot *twice* in the head with a shotgun",
- and since you're dead anyway after the first blast, the second one is
- irrelevant. :-)
-
- Also, is the mirroring of the allowable (not page, dump, etc.) system
- areas a good thing or does it create more problems than it solves? I
- was thinking that we could mirror the critical system areas so that if
- we lost hdisk 3, the contents of hdisks' 1 and 5 would let the system
- continue to run, albeit, the system would run much slower. In the world
- of mainframes we call this "degraded service" which is preferable to no
- service at all.
-
- I have other newbie questions, but I am in the 'designing the basic system
- layout phase", there's no sense in asking them just yet. Hmmm, am I just
- bringing my "archaic mainframe methodologies into the UNIX world", or are
- these 'basic performance/availability concerns' applicable to the UNIX
- world?
-
- Ron,,,
- I am new to UNIX - sorry if these are naive questions! :-)
-