SUMMARY New Disk added. Best way to partition?

From: Jeremy Fichtner (
Date: Mon Nov 22 1993 - 11:10:55 CST

A hearty thankyou to all who responded, I have included their pearls of wisdom below.
After some pondering I have come up with the following set up. ***PLEASE*** critique!
If I'm goning to do something stupid, I'd really like to know ahead of time! I've set it up in Solaris fashion although I'll still be running 4.1.3 for a little while yet.

Although I was urged to give /var its own part, I decided to chance it. I guess if /var/sadm gets big I'll give it the old ---> to somewhere else.

For the SUN0424
Current partition table (original sd0):
        partition a - starting cyl 0, # blocks 33120 (46/0/0)
        partition b - starting cyl 46, # blocks 131040 (182/0/0)
        partition c - starting cyl 0, # blocks 828720 (1151/0/0)
        partition d - starting cyl 0, # blocks 0 (0/0/0)
        partition e - starting cyl 0, # blocks 0 (0/0/0)
        partition f - starting cyl 0, # blocks 0 (0/0/0)
        partition g - starting cyl 228, # blocks 434160 (603/0/0)
        partition h - starting cyl 831, # blocks 230400 (320/0/0)

Projected partition table (original sd0):
        partition a - starting cyl 0, # blocks 72000 (100/0/0)
        partition b - starting cyl 100, # blocks 131040 (182/0/0)
        partition c - starting cyl 0, # blocks 828720 (1151/0/0)
        partition d - starting cyl 0, # blocks 0 (0/0/0)
        partition e - starting cyl 0, # blocks 0 (0/0/0)
        partition f - starting cyl 0, # blocks 0 (0/0/0)
        partition g - starting cyl 282, # blocks 625680 (869/0/0)
        partition h - starting cyl 0, # blocks 0 (0/0/0)


sd0a is the / (root) partition.
sd0b first swap
sd0g is /usr

for the SUN1.05
Projected partition table ( sd1 ):
        partition a - starting cyl 0, # blocks 0 (0/0/0)
        partition b - starting cyl 0, # blocks 204625 (203/0/0)
        partition c - starting cyl 0, # blocks 2052288 (2036/0/0)
        partition d - starting cyl 0, # blocks 0 (0/0/0)
        partition e - starting cyl 0, # blocks 0 (0/0/0)
        partition f - starting cyl 0, # blocks 0 (0/0/0)
        partition g - starting cyl 203, # blocks 1433376 (1422/0/0)
        partition h - starting cyl 1625, # blocks 414288 (320/0/0)

sd1b will be the second swap partition,
sd1g will be /OPT
sd1h will be /export/home

Here is the wisdom I recieved.

From: (Rand S. Huntzinger)

For SunOS 4.x
    You'd want to increase your swap space most likely so you could run processes
which come close to your 64MB and page out inactive daemon stuff so you could get
full use of your memory. Although there are 2X and 3X rules of thumb, I don't know
that you always need that much. Basically, the amount of swap you have is the amount
of virtual memory you have - that is, the total of the sizes of all processes which
can be running. Some sharing takes place, but I tend not to consider it to be
conservative and for simplicity sake.

For Solaris 2.x
   Standard configurations use five partitions, /, SWAP, /opt, /usr and /export/home.
The sizes of these vary according to your needs. You can also separate /var if
you like, or perhaps /var/sadm which is the new biggie. I'd recommend:

        / At least 32MB to allow space for the package/patch databases
                located in /var/sadm. If you separate /var or /var/sadm you
                don't need as much space as SunOS 4 (because /tmp is now in
                tmpfs by default).

        /opt This is the size of the optional software area. I don't know
                what to tell you on this. Allow space for all unbundled software
                you need on the system. This can be big or small depending upon
                your requirements. [However there is no reason you have to
                put all of your unbundled stuff here.] I have a symbolic link
                on my systems from /usr/local -> /opt/local.

        /usr This would be OK, but you may want to pad it a bit more to allow
                for future software bloat. You should be able to put a programmer's
                setup here and probably the full distribution.

        /export/home This is where the /home/<user> stuff goes. They use automount
                to mount /export/home/<user> onto /home/<user> via the auto_home
                automount map. Only you can judge how much you need.

        SWAP This is different from SunOS 4.x. Virtual memory is approximately
                the size of swap + the size of memory. There are some overheads
                involved, but I don't know how large they are. The point is, that
                you need less swap for paging. However, the default setup puts
                /tmp in the virtual memory, so you may want to allocate additional
                swap to accomodate /tmp space.

As it turns out. The big difference in root is the size of /var/sadm. Here is a
du of this area on my Solaris 2.3 machine:

                aslan% du -s -k *
                1348 install
                47 install_data
                18408 patch
                1147 pkg
                3 softinfo

As you can see, there's 20MB here. About 3MB is the install database and the
remainder is the patch area. The patch area contains the old versions of the files
which were replaced when you applied operating system patches. This allows you to
easily back out patches easily and safely (a big win!). However, it takes a lot of
space. That's why I recommend 32MB or more for the root filesystem. Some of the
important jumbo patches are quite large. If you don't plan to apply patches, or
if you want to do it without logging (more dangerous), you don't need quite as much

Hope this is helpful.

                                        Randy Huntzinger


From: Kevin Weinrich <>

The obvious thing would be to move /home to the new disk. You could move
/usr instead, if you needed to. Since some folks recommend your swap space
to be 2 to 2 & 1/2 times your RAM, I would *certainly* add a 64-100 M
swap partition on your new disk. As part of this, I would make /tmp
a tmpfs file system - much faster.

Kevin Weinrich       Atlantic Research Corp. (but I don't speak for them)


From: Doug Gwyn (ACISD/MCSB) <gwyn@BRL.MIL>

A full Solaris 2.2 installation requires 12MB in / and 156MB in /usr, and you need space in /var (at least 5MB, preferably 10MB or more) and /opt as well. /opt depends on what you install; we have the SPARCompiler C, C++, and SPARCworks installed along with User portion of the AnswerBook (rest of the AnswerBook is remotely mounted) for about 68MB in /opt. Since Solaris 2.n where n > 2 may require more space, it is best to leave more room than these amounts, and if you have lots of add-on software it shgould go into /opt so you need to allow room for it there. ______________________________________________________________________________________

From: len@contec.COM (Leonard Mills) In article <> you write: >Any wisdom as to how best chop up these two drives? I plan to go to Solaris 2.X >sometime and I have been warned to have losts of room in the root partion and that the OS will take up around 350 Meg.

You _do_not_ need a big root partition if you make /var a separate mounted file system, which is a good idea even for 4.1.x systems.

Enjoy! -- Leonard Mills

--- _______________________________________________________________________________ Jeremy Fichtner Systems & Network Analyst Ministry of Transportion & Hwys Victoria B.C. Canada (...speaking for myself of course!)

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