SWAP and TMPFS on Solaris8

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1

hi,
With Solaris 8. after I enter df -k, I see 2 lines of SWAP; one is mounted on /var/run while the other is on /tmp.
I remembered that I set up only 1 swap during the installation. Then, a Solaris Admin book says that the TMPFS fils system is a new feature.
Can someone please share his/her thoughts about what the TMPFS is and why this creates 2 lines when entering df -k?
Thanks a lot.

2

The TMPFS is a filesystem contained completely in RAM. Useful if you have an application that writes or reads lots of temporary data, and performance is critical. Only beneficial if you have plenty of spare memory.

3

Thanks for the reply. My question is more about why that the df -k will produce 2 lines about swap, instead of 1.

4

My guess would be that it is because they are two different mounts... Possibly even two different filesystem types. I don't know much about Solaris operations, but that's what I would reckon...

5

Post the output here and we will decode it for you.

6

df -k results below:

========================
Filesystem kbytes used avail cap. Mtd. on
/dev/dsk/c0t0d0s0 1252895 878583 311668 74% /
/proc 0 0 0 0% /proc
fd 0 0 0 0% /dev/fd
mnttab 0 0 0 0% /etc/mnttab
swap 675912 0 675912 0% /var/run
swap 676256 344 675912 1% /tmp
/dev/dsk/c0t0d0s7 243127 131 21868 1% /export/home

Again, I specified to use 512MB for my SWAP size.
Thank you for all the input so far.

7

The /var/run File System

check here

--------------------------------------------------
A new TMPFS-mounted file system, /var/run, is the repository for temporary "system files" that are
not needed across system reboots in this Solaris release and future releases. The /tmp directory
continues to be repository for "non-system temporary files".

Because /var/run is mounted as a memory-based file system rather than a disk-based file system,
updates to this directory do not cause unnecessary disk traffic that would interfere with systems
running power management software.

The /var/run directory requires no administration. You may notice that it is not unmounted with the
umount -a or the umountall command.

For security reasons, /var/run is owned by root.

Hope this help :cool:

8

Thank you. That helps a lot.