Hi, Just providing my 2 cents, take it for what it's worth...
For the 7+ years I have been supporting Linux on System z we have a typical set up of one 3390-9 to contain the SLES installation, one 3390-3 as swap space, and one virtual disk for swap (the size depends on the nature of the server). Depending on the nature of the server (database, web server, or app server) we may create an LVM to contain /opt, an LVM to contain /home, and/or an LVM to contain /tmp. The size of virtual and physical swap space may be adjusted as well. As of 3 years ago all of the disk is fiber connected. Prior to that it was ESCON connected. Hyperpav was enabled in the disk controller about a year ago and we didn't really notice a difference. Thus, we haven't seen a need to enable this support in Linux. We have never had a performance problem that could be related to disk access, though we have had one or more issues with the volume containing root directory, '/', filling up (mainly when /tmp was part of the same filesystem). Even when it filled up, the system kept running without an issue - other than some logging data was lost. I guess that we were lucky in the regard. Harley -----Original Message----- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Offer Baruch Sent: Thursday, December 18, 2014 11:06 PM To: LINUX-390@VM.MARIST.EDU Subject: Re: SLES12 / partitioning Hi There is a good reason to split some directories. /home if set on / fs then any user can fill up your / fs and fail the server. /var might fill up very quickly in different logging bursts or application errors or loops and fail the entire server. No matter how much free space its got Same for /opt /tmp etc... You want to make sure nothing will write logs/data to your / fs. It is not a nice situation to have a full / fs. Sometimes it easy to recover and some times it is a real pain. I always split them up. Another thing is that you really need to use hyperpav with a one disk config. z/VM hyperpav is not enough. You need it inside your linux as well. Offer Baruch On Dec 19, 2014 1:24 AM, "Mark Post" <mp...@suse.com> wrote: > >>> On 12/18/2014 at 09:32 AM, "Levy, Alan" <al...@doitt.nyc.gov> wrote: > > Does it make sense in just setting up one mod 29 (32000+ cylinders, > > app > 21G) > > and let the btrfs use the whole thing instead of breaking it up into > smaller > > pieces (var, opt, home, etc) ? > > Without anything to back this up, my concern is that having everything > on one virtual device number might cause I/O performance problems. > Hopefully someone who does performance analysis for a living is > looking at various layouts and will talk about their results. > > > Mark Post > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, send > email to lists...@vm.marist.edu with the message: INFO LINUX-390 or > visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > ---------------------------------------------------------------------- > For more information on Linux on System z, visit > http://wiki.linuxvm.org/ > ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/ *************************************************************************** The information contained in this communication is confidential, is intended only for the use of the recipient named above, and may be legally privileged. If the reader of this message is not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please resend this communication to the sender and delete the original message or any copy of it from your computer system. Thank You. ****************************************************************************
