Author: Stefan Lechner

friday and disk speed

Post author By Stefan Lechner
Post date 19/02/2021

friday, things to tell

HDD speed test the quick and dirty way (with dd and hdparm)
(be aware only do what you understand, we don’t care if something goes sideways, and don’t blame us it’s your own risk)

Monitoring read and write speeds of storage devices is a good way to determine genuine products and determine disk health overtime. Important: When writing to a device (such as /dev/sda), the data stored there will be lost.
For that reason, you should only use empty RAID arrays, hard disks or partitions. ‘Nuff said !

Server Throughput-1 (Streaming I/O)
# dd if=/dev/zero of=/d3/tempfile bs=1G count=1 oflag=dsync

output something like this:

me-1: 1073741824 bytes (1,1 GB, 1,0 GiB) copied, 10,116 s, 106 MB/s
me-2: 1073741824 bytes (1.1 GB, 1,0 GiB) copied, 5,112 s, 210 MB/s
me-3: 1073741824 Bytes (1,1 GB, 1,0 GiB) copied, 2,7323 s, 393 MB/s

Server Throughput-2 (Streaming I/O)
# dd if=/dev/zero of=/d3/tempfile bs=1G count=1 oflag=direct

output something like this:

me-1: 1073741824 bytes (1,1 GB, 1,0 GiB) copied, 8,5628 s, 125 MB/s
me-2: 1073741824 bytes (1.1 GB, 1,0 GiB) copied, 32,474 s, 33.1 MB/s
me-2: 1073741824 Bytes (1,1 GB, 1,0 GiB) copied, 2,73749s, 392 MB/s

Read Speed
# dd if=tempfile of=/dev/null bs=1M count=1024

output something like this:

1073741824 bytes (1,1 GB, 1,0 GiB) copied, 3,70806 s, 290 MB/s

Read Speed w Buffer
# dd if=tempfile of=/dev/null bs=1M count=1024

output something like this: (this wone should run multiple times)

1073741824 bytes (1,1 GB, 1,0 GiB) copied, 0,324511 s, 3,3 GB/s
1073741824 bytes (1,1 GB, 1,0 GiB) copied, 0,300225 s, 3,6 GB/s
1073741824 bytes (1,1 GB, 1,0 GiB) copied, 0,303069 s, 3,5 GB/s

1073741824 Bytes (1,1 GB, 1,0 GiB) copied, 0,135352 s, 7,9 GB/s
1073741824 Bytes (1,1 GB, 1,0 GiB) copied, 0,131451 s, 8,2 GB/s
1073741824 Bytes (1,1 GB, 1,0 GiB) copied, 0,133496 s, 8,0 GB/s

Read Speed w Cache
#hdparm -tv /dev/sda1

428 MB in 3.00 seconds = 142.61 MB/sec
512 MB in 1.16 seconds = 441.88 MB/sec

Read Speed n Cache
#hdparm -tT –direct /dev/sda1

Timing O_DIRECT cached reads: 494 MB in 2.00 seconds = 246.86 MB/sec
Timing O_DIRECT disk reads: 408 MB in 3.00 seconds = 135.99 MB/sec

Timing O_DIRECT cached reads: 664 MB in 2.00 seconds = 331.58 MB/sec
Timing O_DIRECT disk reads: 512 MB in 1.23 seconds = 417.88 MB/sec

These are some of the methods that can be used to benchmark hard disks and determine their read and write speeds.
For what, yeah it depends … I use it to see if our builds perform, or how long will it take to get the backup done 😉

IT-Stuff

#wordPress hardening wp_xmlrpc

Post author By Stefan Lechner
Post date 19/02/2021

XML-RPC was a solid solution for some of us, till the day when problems occurred due to remote publishing
to a WordPress site. However, with wp_xmlrpc, just because the XML-RPC specification was developed
before WordPress was even created, came some security holes that ended up being pretty nasty
for some WordPress site owners.

One Way or another, there are always ways trying to avoid getting on this trail,
use plugins, or some code, which means you are going to disable that features (wp_xmlrpc) entirely.
When you’re on that golden road, that you need some features, you should use the work around plugIns
available for these features.

Getting more sleep and less headaches, the way we handle it here, is adding some code to .htaccess.
(be aware and knwo what you are doing, we don’t care, and we are not to blame if somehing goes wrong)

# ---- Block WordPress xmlrpc.php requests ----
    <Files xmlrpc.php>
    order deny,allow
    deny from all
    </Files>
# ---------------------------------------------

This will disable wp_xmlrpc, and answer requests with 403.

islba-company

a new week

Post author By Stefan Lechner
Post date 08/02/2021

... a fresh start on Monday ....

I can’t care less if this was ever a friday afternoon problem. Let’s go!

And the Week starts with something like this …...

Client Call … have I been hacked or is just my hardeware dying
Log File Check
Call Hardware Folks
Call Legal

oh boy a week can’t start better ….

IT-Stuff

Hardening WordPress

Post author By Stefan Lechner
Post date 01/02/2021

most of the time when it comes to hardening an existing #wordPress installation or site, we are all used to listen to the same old tunes.

run update to the latest version
remove unused PlugIns
run update on used PlugIns
check twice if you need the PlugIn for real (else get rid of it)
disable PlugIns that run out of updates or look forward to replace them
minimize user permissions (not all yout users need to get admin privileges)
sort out users (users that no longer need access have to be removed)
use 2FA (google authenticator does the trick pretty well)
protect your login page
limit login attempts

But here are commin the new tunes …..

Disable PHP error display:
a simple edit of the site’s wp-config.php file with this code should do the trick

define ( 'WP_DEBUG' , false);

Disable PHP execution in untrusted folders:
this is a pretty new one for me, that you can guard against it with a simple access control file.
just a little code is needed in .htaccess
We have to test this well, because I think, you can pretty fast overusing this restrictions, and most of WordPress involves PHP execution.

<FilesMatch "\.(php|php\.)$">
Order Allow,Deny
Deny from all
</FilesMatch