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- Path: sparky!uunet!gatech!europa.asd.contel.com!emory!sol.ctr.columbia.edu!The-Star.honeywell.com!umn.edu!uum1!gw.digibd.com!rogue!rhealey
- From: rhealey@rogue.digibd.com (Rob Healey)
- Subject: Re: 'Proper' filesystem distribution
- Message-ID: <C1F7x3.78G@gw.digibd.com>
- Sender: news@gw.digibd.com (USENET News)
- Nntp-Posting-Host: rogue.digibd.com
- Organization: DigiBoard Inc., Eden Prairie, MN
- References: <Bradb.0oco@nesbbx.rain.COM>
- Date: Mon, 25 Jan 1993 17:43:49 GMT
- Lines: 84
-
- In article <Bradb.0oco@nesbbx.rain.COM>, Bradb@nesbbx.rain.COM (**) writes:
- |> (I wanted to follow-up to something rhealey@rogue.digibd.com (Rob Healey)
- |> said about Amiga Unix not liking / and /usr on seperate file sytems but I
- |> can't seem to find the article so here goes...)
- |>
- Gee, that's me!! B^).
-
- |> What is the 'proper' distribution of filesystems assuming that you have
- |> several drives, each of (approximately) the same access times?
- |>
- Religeous issue actually and normally involves an iterative process
- as you figure out the dynamics of your particular setup. You can
- make generalizations, and the 4.2 UNIX manuals that come with UNIXware
- do give some good pointers in this dept, but in general you have to
- take some data and analyze where your drives are spending the most time
- and put the popular stuff there.
-
- |> I've got a 300MB and 2 150MB drives and I'm wondering how I should split
- |> out the file systems to get the best performance. (I'm getting a 600MB
- |> disk from work for Usenet and to keep sources on, so I'm just thinking
- |> about the basic stuff on the other drives...)
- |>
- |> Unix people at work suggested the following distribution:
- |>
- |> 150MB /
- |> 150MB /usr
- |> 300MB /home
- |>
- The UNIX people at work don't have AmigaUNIX... The / and /usr
- dependancy is due to some AmigaUNIX setup dependancys that
- assume / and /usr are on the same slice so hard links and
- other things work. If you break up / and /usr on AmigaUNIX I
- believe the startup scripts/programs will break. I've never had
- the time to putts with this and since I can use ufs, and thus
- don't have to worry about 65500 inodes/slice limits, I can keep
- both on the same slice.
-
- |> Any comments? Is this bad? Good? (Also recommended to have a swap
- |> partition on *each* drive equal to the amount of 'real' memory)
- |>
- Hmm, I'd say 1 swap partition twice the physical memory size should
- be enough on most SVR4 based systems. SVR4 is a little better with
- memory that BSD or SVR3.2 so twice physical on 1 slice should be
- enough. You can add a paging file via the swap command if you
- ever need it but I doubt you will. The one case I've seen problems
- with is compiling gdb 4.7, for that I had to set my memory limits
- from 16M/process to unlimited so the damn thing would link! Luckily
- 32M of paging area did the trick and it was just a ulimit problem.
-
- |> Is it possible (and desirable?) to have multiple swap partitions, each on
- |> seperate drives?
- |>
- Swap on a drive not containing active file systems MIGHT be a good
- idea but it's a bear to get right under AmigaUNIX due to the way
- you have to compile the kernel. The other issue is that those other
- people are probably giving you advice based on SunOS, BSD or SVR3.2
- experience which isn't always accurate for SVR4. Especially in the
- paging dept, what's good for SunOS,BSD or SVR3.2 might prove overkill
- for SVR4. SVR4 pages text area from the executable image on the
- file system and data areas are shared copy on write. Additionally
- ALOT of code is in dynamic librarys that don't touch the paging area
- either. So, SVR4 tends to use alot less paging area than the other
- OS's.
- ( A note for you pedantics out there, yes I know I've over simplified
- the explaination of SVR4 VM...)
-
- Since AmigaUNIX has other efficiancy problems, it was never tuned, I
- would say stick with the stock setup slices and put user file
- systems on the second drive leaving /,/usr and paging on the first.
-
- By the way, has anybody tried tuning the variables in kernel.h? While
- looking over the UNIX 4.2 manuals that come with Univel I noticed that
- a 16M machine should have BUFHWM set to 1024, AmigaUNIX had 200. This
- supposedly sets an upper bound on the number of disk block buffers
- the kernel can alloc(). I up'd it on kas and it seems to have
- improved disk performance a bit on compiles. Has anybody found any
- other tuneables worth tuning?
-
- I wish somebody would do a 4.2 port to the Amiga, the new X based
- debugger, X application building and other tools are making my
- mouth water... Oh well, I guess I'll have to play with 4.2 at the
- office instead...
-
- -Rob
-