The issue is when you need to echo something as root/sudo, that it doesn't work. You can never do a sudo echo to an output file as you'd expect.
Take an example to clear out wasted RAM buffers/cache like this:
sudo echo 1 > /proc/sys/vm/drop_caches
-bash: /proc/sys/vm/drop_caches: Permission denied
The solution is to run tee as sudo/root
What we do is echo 1, but then pipe it to the "tee" command as sudo........
Bonding is an excellent way to get both increased redundancy and throughput. It is similar to the "Network Teaming" feature in Windows.
There are a few different modes but we will use mode 6, I think it's the best of both worlds, as it is not just a failover, but it provides round robin, so you will get redundancy and load balancing. So if you have a 1G single port, you will have a combined throughput of 4G at this point. Just bear in mind that the true thr........
cat .htaccess
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . index.php [L]
I keep reading there is a "# BEGIN WordPress" and a "# END WordPress" in the wordpress htaccess above but there is clearly not.
Even more strange is that my permissions are just 444 (read only).
so i changed it........
It is really simple using .htaccess with mod_rewrite.
Here is all you need:
RewriteCond %{SERVER_PORT} 80
RewriteRule ^(.*)$ https://site.com/$1 [R=301,L]
Another more graceful way is to use the %{SERVER_NAME}variable to make it dynamic. Just be careful that the server name will always match what you expect. (eg. if you are doing load balancing or clustering what if the server name may be somethi........
Before getting into the output here is my typical experience with SMART, there is what I call a "bad disk" with pending and uncorrectable sectors that cannot be reallocated.
It has caused a kernel panic and system crash repeatedly as we can see from the logs.
But SMART says it has "PASSED" its self assessment. SMART is still useful to me but it is more about looking at Current_Pending_Sector.
Any time I have had anything but 0 for that attribute it........
You get errors like below and see you have all question marks for the permissions if you go to /run/user/1000/gvfs
If you try to access the mounted share such as anything mounted as gvfs like an SSH share in your file manager you may get an error like this. It generally means an interruption in communication or a fault with gvfsd has caused it.
Solutio........
user@box:~$ sudo tune2fs -l /dev/md99
[sudo] password for user:
tune2fs 1.42.9 (4-Feb-2014)
Filesystem volume name:
Last mounted on: /mnt/md50
Filesystem UUID: 976a8655-2619-4587-878c-dab07f7b7652
Filesystem magic number: 0xEF53
Filesystem revision #: 1 (dynamic)
Fi........
It is possible to tell mdadm to create an md device on a raw disk even though it will give you an error, it writes a superblock and this corrupts the partition table which can result in your system not booting.
To fix it just zero the super-block on the offending device that you made the mistake in.
Eg: /dev/sda
mdadm --zero-superblock /dev/sda
It is also a way of starting fresh if you wanted to create a new array.........
To first start off, there are many misconceptions about NoSQL and especially its strengths and weaknesses.
Even the popular NoSQL solution MongoDB is fraught with issues that no one seems to be concerned about aside from a few but there are serious issues with database integrity and verified writes. MySQL was considered dangerous or incomplete at one point without having the transactional safety features of Oracle for example.
However the NoSQLimplementations seem........
02:00.0 SCSI storage controller: LSI Logic / Symbios Logic SAS1068E PCI-Express Fusion-MPT SAS (rev 08)
03:00.0 SCSI storage controller: LSI Logic / Symbios Logic SAS1068E PCI-Express Fusion-MPT SAS (rev 08)
Basically these cards are a stripped-down version of Dell Perc 6/i only they (SAS 6/ir) support JBOD.
The DellPerc 6/i are basically useless because it doesn't have JBOD support and requires software or BIOS commands to add or remove........
I bricked one of my cards by following a guide from UNRAID.
Step #1 from them wipes out the BIOS, but guess what? The step where you restore the BIOS should have been done first, which is sas2flash but no version supports or is able to find my Perc 6/i. So now I'm a bit stuck.
I tried using megarec but it's funny that it can wipe the BIOS but can't forcefully reload it:
megarec -writesbr 0 mpt2sas.rom
Supports 1078 control........
LSi Megaraid
At first it was configured as a RAID 0, then I deleted the Virtual Disk Group.
I thought both drives would be shown and detected in Linux as sda and sdb but it actually shows nothing.
To make them work you have to hit Ctrl+R before the system boots (when prompted) and create a Virtual Disk Group. In my case I created each one as RAID 0 (with a single drive only) as I just wanted JBOD but there is no such option or default in these Dell Pe........
qemu-img create -b centos.5-8.x86.20120308.qcow2 -f qcow2 ../kvmguests/25000-centos5.8x86.qcow2
Formatting '../kvmguests/25000-centos5.8x86.qcow2', fmt=qcow2, backing_file=centos.5-8.x86.20120308.qcow2, size=10485760 kB
-b the source/base image
-f format is qcow2 and the location of the destination image
What is so special about this? It's even quicker than creating a template with OpenVZ but this is an actual OS.
It saves time a........
don't delete /var/lib/mysql/ib_logfile0 or ibdata1 or mysql won't restart
I didn't realize they were internal and not part of replication like the relay files!
/usr/libexec/mysqld: ready for connections.
Version: '4.1.22-log' socket: '/var/lib/mysql/mysql.sock' port: 3306 Source distribution
110127 16:31:00 [Note] /usr/libexec/mysqld: Normal shutdown
110127 16:31:00 InnoDB: Starting shutdown...........
Here is a RAID 1 partition (500GB Seagate & 2TB WD):
Sequential Reads
File Blk Num Avg Maximum Lat%&nbs........
This drive is clearly on the way out, the Kernel knows it but I'm surprised that SMART is not concerned. I didn't blame Seagate for their past issues until now. This hard drive has hardly been used and has not even been powered on for a year according to SMART.
Home page is http://smartmontools.sourceforge.net/
=== START OF INFORMATION SECTION ===
Model Family: Seagate Barracuda 7200.11
Device........
Seagate Inventory/Firmware Check
I heard about this issue a long time ago but never looked into it. I figured I wasn't affected since my 500GB drives were running for so long. I've been using Seagate's since 2002 and to this day all of the drives I have are alive from Seagate.
*Update the bad news is that I realize one of my 500GB's is about to die, it's not even a year old, but is also not affected by the recall according to Seagate!
Seagate Inventory/Firm........
This happened with a select statement which writes the result to an external file. I didn't remember the privilege "FILE" must be granted on *.* for this to work successfully, it wasn't actually an authentication issue as it implies since I was already in the SQL prompt and doing the query.
SELECT some_id
FROM sometable
INTO OUTFILE '/tmp/result.txt'........
The results are still not flattering and are nothing close to native performance. Unless GlusterFS has a "DRBD-like" option to delay writes over the network and to only read from the client side, I don't see how performance can ever improve much more.
After doing some client optimizations Iadded more to the score:
Start Benchmark Run: Sun Nov 29 00:37:44 PST 2009
00:37:44 up 3 min, 1 user, load average: 0.01........
I've tried to find a good sensible solution to cluster with and each technology has it's pros and cons and there is no perfect solution and I've found a lot of "exaggerations" in the applications, benefits and performance of these different filesystems.
DRBD
I first started off with DRBD and Ihave to say it does live up to the hype, is quite reliable (although it can be annoying to match up the kernel module and user applications since they must match and whe........
In Newer Linux Distros This Way Is Easiest and works on newer versions like Ubuntu, Mint, Fedora, Centos, Debian etc.
#if you are missing timedatectl this in newer distros like Ubuntu/Mint/Debian and are using a container like Docker then do "apt install systemd"
timedatectl set-timezone America/Vancouver
Replace the America/Vancouver with the correct timezone.
To see the list you can just type "timedatectl set........
Backing MySQL Databases
Backing Up/Dumping All Mysql Databases To A Single File
mysqldump --all-databases -u admin -p > allmysqldatabases.sql
The "-all-databases" clause is pretty obvious isn't it? It means that it will backup all databases.
The "-u admin" means login using the user "admin", if you h........