Subject: Suggestion: don't mount 16 MB tmpfs into /tmp per default
From: Patrick Nagel <patrick.nagel@star-group.net>
Date: Wed, 14 May 2008 15:30:55 +0800
Wed, 14 May 2008 15:30:55 +0800
Hi,

I'd like to suggest removing (or commenting out) the line

'none    /tmp            tmpfs   size=16m,mode=1777      0 0'

from the default /etc/vservers/<vserver>/fstab.

I ran into trouble with this default setting twice.
Once I tried to build OpenOffice - the build process needs huge amounts of 
space in /tmp, so it failed. The other time was yesterday / today when 
dovecot's LDA couldn't temporarily store mails in /tmp because of 
insufficient space (see my posting on the Dovecot mailing list: 
http://www.dovecot.org/list/dovecot/2008-May/030719.html).

I brought up this topic on the IRC channel, and got the information that "if 
you have 100+ guests, each with 5 processes banging on /tmp for extremely 
short temporary storage, you definitely want that to be in memory not on your 
main disk" (read the full conversation: `curl -s 
http://irc.13thfloor.at/LOG/2008-05/LOG 2008-05-14.txt | grep -A 
20 "^1210736428"`).

In my opinion, this default setting has too much potential of causing 
(sometimes hard-to-debug) trouble. The few Linux-VServer users who run 100+ 
installations should be able to figure out on their own that they should put 
guest's /tmp into a ramdisk, if a lot of accesses to /tmp cause performance 
issues.

Patrick.

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