What prompted this thought/question was... This happened a few weeks ago.... One of my LPARs had the wrong permissions set for /dev/null, and had been that way who knows how long. Just kind of feel foolish when a user comes to me to complain that he's getting a security violation trying to write to the UNIX version of "DD DUMMY".... By the way, the permissions for /dev/null are "supposed" to be 777 - it's in the manual, once I looked it was obvious. Also, if not present, the system will create /dev/null with the correct permissions, but will NOT fix permissions which are wrong if /dev/null already exists. One reason to consider creating /dev at every IPL, in memory.
Upon further research, I found that there's been some (not recent, 2004) APAR activity indicating a defect (long since fixed) for a customer who was using a TFS for /dev and had some minor problem. So I figured some customers must be using this technique. What tipped the scale was I just noticed that I'm getting millions of SMF type 92 subtype 10/11 records *per day* *per LPAR*, for LPARs running SAP. Did this just start happening? No, but we just moved one SAP environment to an LPAR which hadn't had it before, and that's where the change became noticable. I checked with IBM, and high activity to /dev/null for SAP is normal - they suggest considering turning off type 92 subtype 10/11, which I am thinking about doing - the other option apparently is to suppress certain SMF records via SMF exit. If we're using /dev/null that often, it's got to be more efficient to use a memory only structure, or so I figured. Ok, it's a slow week! Brian On Tue, 20 Jun 2006 20:42:10 -0400, Bob Rutledge <[EMAIL PROTECTED]> wrote: >As you say, there should be no need to keep it over IPLs. We've had it a TFS >since 1.4 with no problems and no need to futz with a physical filesystem. > >Bob > >Brian Peterson wrote: >> Looking for advice.... >> >> On z/OS 1.7, should the /dev file system be defined as a TFS (temporary >> file system)? The manuals seem to indicate that all character special >> files in /dev get created at IPL time anyway, so why not have this file >> system be a TFS? >> >> Pros? Cons? ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
