Moving /usr/lib directory

Question

Hi all,
I have a SUN Ultra Sparc 60 running Solaris 7.
I tried to move the /usr/lib directory to /opt/usr/lib in order to get more disk space in /usr because if was almost full (it was not a good idea, I know it now). My idea was to make later a soft link in /usr to /opt/usr/lib, but when I tried to do it (ln -s /opt/usr/lib) this and almost all the other commands didn,t work. It is logical now, they can't find the needed libraries in /usr/lib because they are not there now. I tried some things to move /usr/lib to its original place but I didn't have luck (cp mv, ...). Finally I restarted the Workstation and, of course it couldn't boot. I can only enter in the System Maintenence Mode like root. I can't do so much there. Worst, I can't enter in the /opt/usr directory and fsch doesn't work neither.
My question is, is there any way to recover the system from this situation??
Any help would be appreciated. Thanks.
Alex
PS: I have another identical system working close to this one, if that can help in anything.

Answer 1

You can move any directory's contents to another directory using the following commands:
cd <from_directory>
tar cf -. | (cd <to_directory>; tar xvf -)
In your case, you need to boot the corrupted system into single-user mode, mount all volumes and then manipulate the directories.Generally speaking, what happened to you is the result of a very odd UNIX sysadmin's misconception: everybody thinks that under UNIX hard drives need to be partitioned. They don't know why, but they "have always done it that way". When you are planning the system's layout it is very difficult to predict exactly how much space a particular directory will take up. And here is the best part -- they recommend that "/" partition be set to about 100 MBytes. Just imagine what happens if you create a "/big_files" directory (or installer does)! Partitioning also increases the drive contention because the drive heads need to constantly jump between different partitions (the system doesn't know that the partitions are not "real" harddrives and tries to read/write on all of them simultaneously). The solution is -- not to partition the drives. Just put everything on "/" partition which is easy to set to 100 GBytes these days. This way you are safe from running out of space in "/big_files" directory (at least for a while).
You may be wondering, what about the "swap" partition? the answer is very unorthodox -- don't do it! If you really need swap -- create a swap file. The only good reason to put swap on a separate volume is when you actually have a separate hard drive just for swap. Otherwise the drive contention will kill you. Once we're at it, how big would you say the swap file should be on a system with 2GB of real RAM? "They" say it should be twice the real RAM. Well, that's ridiculous -- you need swap because you don't have enough RAM, but by their logic, the more RAM you have the more swap you need. Again, unorthodox solution -- if you have 2 (3, 4... 8) GB of real RAM you don't need swap at all. Use your cabesa, UNIX computer science is very old -- it does not neccessarily apply to modern computers.