You have a directory that you want to password protect, lets call it “secrets”.  It resides in /home/mysite/public_html/secrets/ on the server.  Now fortunately you are using a hosting control panel like cpanel and you’ve password protected directories before (if not then have a hunt on this site or on google!).

Before you activate the protection you can view the contents fine, so you activate protection – driven by a .htaccess file… and then rather than being asked for your username and password, you get a 404 or a 403 message from wordpress “Sorry the page you are looking for cannot be found”.

Intrepid system administrators hunt through error logs, and sure enough the access log is recording a 404… however the error log is recording something different.

Permission denied: /home/mysite/public_html/secret/.htaccess pcfg_openfile: unable to check htaccess file, ensure it is readable

This error message has had a number of solutions in the past, including the infamous “reinstall frontpage extensions”, except these are long gone – not supported and never will be again, please don’t go installing them just to get past this problem! – It will end in tears.

Instead you just need to add a couple of lines to the wordpress .htaccess file in the root of your site (e.g. /home/mysite/public_html/.htacess). Go to the file and just before the main WordPress part

#BEGIN wordpress – add the following

ErrorDocument 401 /%{REQUEST_URI}/errors.html
ErrorDocument 403 /%{REQUEST_URI}/errors.html

This should set the site to working, now why does this work?

Simply put wordpress is often run with a pretty url mode (permalinks) where the addresses for posts are made to look more pretty.  When you request your secret directory the server tries to access it, looks at the .htaccess file and promptly tries to do a redirect, this invariably ends up at a page wordpress cannot access – this doesn’t happen without the .htaccess as wordpress allows access to existing real files, but the htaccess security says the file doesn’t exist until the password is entered and so it intercepted.

It’s all a bit confusing, however adding these lines essentially means wordpress can get out of the way when those errors occur, 401 and 403 are authorisation required or failure codes, so wordpress will ignore and the htaccess can safely challenge your.

Hopefully this will help if you come across this problem.

Mod Deflate is essential nowadays for sites, it speeds up the transfer of html pages & other files (such as stylesheets) by compressing them first. Now that servers today are so powerful there is very little reason not to use this, especailly since so many “speed up” tests will not pass without this being enabled.

However whilst you can enable it site-by-site, however for shared hosts with many sites this is not the best way, but you can enable it globally.

1. First ensure it’s installed, you can do this by using EasyApache and ensuring that mod_deflate is selected (it may be already),once apache has been compiled deflate is now enabled.
2. If you want to enable the functionality site-by-site then in each sites control panel a new option is now available.  under Software/Services the user can now choose to optimise their website, this essentially allows deflate to be turned on and off.
3. If you want to do this globally (why not it cuts bandwidth and keeps your users happier) then  simply follow the following:

• Under Services Configuration / Apache Configuration / Include Editor / Post Virtual Include
• Select All Versions (no point in not doing all versions)
• Paste the following into the file and then click Update.

<IfModule mod_deflate.c>
SetOutputFilter DEFLATE
<IfModule mod_setenvif.c>
# Don’t compress images its a bit pointless
SetEnvIfNoCase Request_URI .(?:gif|jpe?g|png)$ no-gzip dont-vary
</IfModule>
<IfModule mod_headers.c>
# Make sure proxies don’t deliver the wrong content
Header append Vary User-Agent env=!dont-vary
</IfModule>
#maximum compression - why not we have spare cpu
DeflateCompressionLevel 9
</IfModule>

What I mean is using somthing like ftp, or copying to my desktop and then up to the other server – all hassle (and in the case of ftp – inherently insecure).  Why do I do this?  Well not because there’s no alternative, but because I can never easily remember how to do it the “proper” way.

So how to do it – simply use SCP, this copies a file using SSH and so is more secure (we trust SSH right?), even better I’ve never had a server which doesn’t support it out of the box.

Right so how to transfer one file:

scp /sourcedir/filename.extension user@serverip:/destinationdir/

It’s quite simple really – if you run SSH on an abnormal port (you really should it cuts down the attacks) then you can specify the port like this:

scp -P 2100 /sourcedir/filename.extension user@serverip:/destinationdir/

Also, if you want to transfer multiple files (e.g. all the images in a directory) then you can just use wildcards – like below:

scp -P 2100 /sourcedir/*.extension user@serverip:/destinationdir/

SMTP Error: SMTP error: Connection failed: Failed to connect socket: Connection timed out.

After reading a few things  I turned on the SMTP tweak..  things appeared to work for a few hours, then it started failing again.

Searching online said to trying telnet on the command line – so did that, connected to port 25 – all fine… hmm odd – tried webmail again – failed…..

After a more indepth search I found a forum which gave me a hint – apparently other people have had the same problem when using the firewall for cpanel – CSF.  CSF is definately one of the best firewalls around for linux and works really well with Cpanel – however every now and again the amount of options can cause you to miss out something obvious:

# If SMTP_BLOCK is enabled but you want to allow local connections to port 25
# on the server (e.g. for webmail or web scripts) then enable this option to
# allow outgoing SMTP connections to 127.0.0.1
SMTP_ALLOWLOCAL = 0

The SMTP_ALLOWLOCAL set to 0 stops webmail etc… not sure when this appeared (the server has been working fine for about 4 months) but change it to 1 – restart CSF and there we go it’s working fine

You’ve logged in as root to check – and yup you still can’t write any files – even a “touch test.txt” fails with a message saying can’t write file – disk or partition full?

You could be out of inodes! Linux stores file address information in inodes – and if you have a lot of very small files (or quite an oddly setup filesystem) you could be out of inodes…

How do you find out though?

just type in

“df -i” – same as the normal diskfree space command except it tells you inodes, if you have none left (or very few) you may not be able to create a new file (or edit it if your editor creates temporary lockfiles).

In a future blog I’ll go through how to resize the number of inodes available (primarily aimed at your temporary dev/shm space as this can suffer from the inode problem if you allocate more to it from a small size – the number of inodes is not increased so you can run out).

For some reason some hosts will give little storage to partitions which then get filled up unexpectedly.

To find out how much space you have just use the following command.

df

- want to make it more readable?

Use df-h

Also if you want to see your diskspace changing over time the you can use the watch command. For example

watch -n 1 “df”

This will run the disk space command each second and you can view it’s output on the commandline – useful if you want to monitor some specific activity in real time.

umount tmpfs

The above command will ask the OS to unmount the filesystem identified by tmpfs in the fstab file.

This may return an error if you are actively using it – i.e. you have an ssh session open and are in the filesystem or open files exist. – Exit any of these and try again

mount tmpfs

The above command will attempt to re-mount the drive.

When would you use this?  Normally if you have done some dynamic re-sizing of a partition  - for example the tmpfs partition – see post:

http://www.ihelm.org.uk/2010/04/resizing-ram-disk-in-linux-devshm/

for more info on how to do that.

However sometimes you may decide the 50% is not enough (or is too much) – especially if the server is upgradeable you may decide you would want to manage the percentage.

Below is an example default entry from /etc/fstab

tmpfs                           /dev/shm        tmpfs   defaults        0 0

This just creates the temporary system using default settings – nothing fancy – however if you want it to take 75%  of your ram (or any other percentage) just change it to the code below

- reboot (or remount) and your done.

tmpfs                           /dev/shm                        tmpfs   size=75%                                0 0

How to unmount the tmpfs

umount tmpfs

To remount it with the new settings

mount tmpfs

The Cpanel system has a feature to migrate accounts from another server – be it Cpanel or another webhosting panel – this often works, recently though I’ve had a problem with using it for Cpanel to Cpanel where it would connect but fail to transfer the backup file.

Fortunately it’s really easy to use the commandline with cpanel and you can do it manually (actually it’s easier than the wizard!)

On the server you are migrating from just type (while logged in as root!)

/scripts/pkgacct username

This will create a tar.gz in the /home directory on the server – just copy this to the new server (it could take a while – it has everything from the account you are copying).

On the destination server just type in

/scripts/restorepkg username

This creates (or overwrites the account!) on the server – and your done!.  But what if you have a dedicated IP (due to SSL?)

Easy just use this instead

/scripts/restorepkg –ip=y username

This gives it the next free dedicated IP address (make sure you have one free!)

And that’s it – it is honestly easier than the wizard which requires you to add more info to establish the transfer link.

One thing to note is that you should ensure that the versions of cpanel are as near as you can get – otherwise it might fail or do things a little weird.

If you want to see what exim is doing right now :

“exiwhat”

if you think you have queue problems then you can print a countof messages in the queue this will often be quite high – so it’s worth running it a few times over a couple of hours to see if you have a queue problem:

“exim -bpc”

If you want more information about what is in the queue then the following command will give you the count, the colume, oldest, newest, domain to be sent to and total summaries.  The oldest and volume parts are often the most informative in this to help you see problem domains.

“exim -bp | exiqsumm”

Below are some commands to help you manage the queue – especially useful if you want to try to purge it or take action.

To tell exim to try to deliver things in the queue according to the rules for a queue run

“exim -q -v”

If you are blocked up with external mail you can tell exim to run the queue to deliver local mail only – this may help you get things such as notifications etc.. if they are delayed by other mail in the queue

“exim -ql -v”

If you have some problems with older mail (maybe spam related) – you can use the following to delete mail that over 7 days old (the time given is in seconds so just take one day 86400 and multiply it by 7)

“exiqgrep -o 604800 -i | xargs exim -Mrm”

There are many many other commands and other examples – some sites have longer lists, but these are all the commands I have needed (or variations thereof) for administrating my servers over the last 9 years.