4,809 reputation
11236
bio website mattdm.org
location Somerville, MA
age
visits member for 4 years, 2 months
seen Dec 15 at 22:27

I'm the Fedora Project Leader. I work for Red Hat — and for the Fedora community at large! – but my posts here are all my own.

Previously, I was a sysadmin in the Academic Computing group at Harvard School of Engineering and Applied Sciences, and before that, I made Boston University Linux.


Nov
11
comment How to keep cron from stampeding?
run-parts is present in Fedora / Red Hat systems too.
Oct
31
comment Why is a computer registration system nessesary on a college campus?
Sure it is. But that sounds like another question.
Oct
21
comment .bash_history permissions mysteriously changed
$ sudo su ; # echo $HOME → /root ; # echo $HISTFILE → /root/.bash_history
Sep
26
comment Can KVM suspend or shutdown guests automatically on host shutdown?
Hmmmm. Yeah, it's also suspiciously missing in the code. What the libvirt-guests script actually does is run virsh managedsave. (It looks like maybe only the UML driver supports system_powerdown.) Thanks for the catch! I'll update my answer, and file a bug against the documentation.
Jul
30
comment How do you upgrade PHP 5.1 to PHP 5.3 using yum on CentOS
There really isn't any CentOS version but the latest; if you initially installed CentOS 5.1 and kept up with patches, you have 5.6. (And if you haven't kept up with patches, please don't install PHP.)
Jul
30
comment How do you upgrade PHP 5.1 to PHP 5.3 using yum on CentOS
This is not necessary, and also has some disturbing repercussions. For one, now you've not got an easy source for updates for php, and while php is better than it was for a while there, php is generally something you want to stay on top of security patches for.
Jul
30
comment How do you upgrade PHP 5.1 to PHP 5.3 using yum on CentOS
possible duplicate of How do I install php 5.3 on CentOS?
Jun
3
comment How do I see how quickly items are dropping out of memcache?
Oh I see. Not telnet to the server system; use telnet to open a tcp connection to the server port.
Apr
25
comment What is a “Cloud Provider”?
possible duplicate of What is "Cloud Computing"?
Apr
25
comment What is cloud computing?
possible duplicate of What is "Cloud Computing"?
Apr
22
comment awstats password protection
Have you followed what the message said and checked the AWStats documentation?
Apr
7
comment Moving/Adding Additional Swap Location - Redhat 5
Are you sure that swap is filling up /, and not temporary files (or log files, or something else)?
Apr
7
comment Moving/Adding Additional Swap Location - Redhat 5
@rkalajian — look at man swapon for how to set the relative priority of your swap devices. (This can go in fstab, too.)
Apr
7
comment Moving/Adding Additional Swap Location - Redhat 5
You can also use files; you don't have to use partitions, and you don't have to use something like swapd to do so.
Mar
31
comment How do I install PHP 5.3 on CentOS?
Yeah. :( lwn.net/Articles/435744
Mar
9
comment How can I disconnect ssh users, or limit the number of ssh logins?
There's always the "If you are caught logging in from two places simultaneously, there will be consequences." approach.
Mar
9
comment How can I disconnect ssh users, or limit the number of ssh logins?
@mmr — cryptographic tokens are a good way to deal with that. :)
Mar
9
comment MPM Prefork, too many apache2 process?
@yes123: if you're hitting the suggestion to raise MaxClients and you're already at the reasonable limit for your server size, you need more RAM.
Mar
9
comment MPM Prefork, too many apache2 process?
@yes123: don't worry about the virt usage — sorry for stressing you out about that yesterday; I was being a little overzealous and should have caught that. It's the RSS that is closest to meaningful and what you should size the maxservers/maxclients setting by.
Mar
9
comment MPM Prefork, too many apache2 process?
@yes123: you just never got the traffic to fire them all up. It's definitely the problem. If requests overcome that limit, people will have to wait. But that's a lot of requests — you say your longest php script takes 0.09 seconds to load, so worst case each one can handle 11 requests a second. Are you really likely to serve over 3000 requests a second? And if you are, can the CPU keep up with that? If you're hitting that problem, you need a bigger box.