Road

When I joined wordpress there was this challenge called the word of the day. Or the word of the week, I don’t remember. This is not about this, but somehow, it’s inspired by that movement or whatever that was. Because this is a single story, each post strongly linked with one word. The first one was Monster.

“You are very wise, my lord. Sometimes I forget you are a well educated knight.” Sir Reg already stand up from his stony stump and started again walking down the road.

“Well…let’s say I will not list your last comment as an offensive one.” The warrior slows down his speed to stay closer to Janus. “It is true that I was not the smartest on my class. I can say I mainly hated the lectures on the Castle where I trained with the other Laria knights. I didn’t see any use of learning algebra, geography, protocol, or dynasty. What I did love were the practicals. The teachers, the old bastards, were cooking up situations, they called them. Typical, so to say, like a group of morons trying to rob an old man, a lady in distress, those things. Probably you can imagine them.” Janus nodded. “At that moment I didn’t understand what they were for. Now I know the reason behind, they were trying to built on us some kind of sense of righteousness that a normal peasant, like you, if you were not a sorcerer, of course, don’t have. I can proudly say on the practicals, I was always the best. As a consequence, I have a rock hard morale and a very analytical mind when a riddle of the type a knight is supposed to solve is presented to me.”

Janus sighted, trying not to be heard by his party mate. And he was supposed to be able to solve magical problems, of course. Unfortunately he didn’t have practicals on his university, or at least, not on his course. The image of Radin, Oystre, Lumarr and the others facing an adventure like this one made him smile. He lost track of them, if he manage to leave this place, he said to himself, he will try to contact the lads.

So they keep walking happily down the hill, hoping to find an exit to the dungeon because this is what is supposed to happen. Janus didn’t delete the smile on his face for a while, Sir Reg on the other hand, started to hum another dirty tavern song.

The static sun started to bite their skin. Some fumes emerged between the forest of stalagmites they were crossing. The water vapour, without any wind, was drawing around them ghostly columns, from time to time creating clouds that covered drastically the light, making Janus remember that he should be deep underground, not on a happy picnic on the field. A sudden claustrophobia evolved on him. What if the sun was not a sun, and this was indeed some kind of closed ecosystem? What if the circle above was just a giant crystal belly filled with flowing hot and shiny lava that was periodically getting cold by natural means?

“I think we should be about to arrive.” The voice of Sir Reg kicked Janus out of his dark thoughts. “Don’t you see a brightness after the next hill? That should be it!”

“Well we still need to go through that grey esplanade before.” The esplanade, as long as a battlefield, was separated by the narrow black road, that cut through it like a scar on a shedding skin. Here and there, ominous fumes were rising. Over the hill, what looked like broken carved pillars on both sides of the road were waiting them. The pillars of a door, most probably. Hopefully a door out.

Sun

I used to write some kind of description of what’s going on at the beginning. But this time I will simply refer you to the previous introductory paragraph, Watchtower. Enjoy the next instance of this uncanny adventure…now.

“Unfortunately, I can’t tell you what is that over there beyond the fact that you are right, there is something silvery and shinny. ” After the affirmation, Janus disappeared from the field of view of Sir Reg. The knight circumvallated the broken stalagmite until finding the shaking legs of the magician, looking for a way down the watchtower. “I’m sorry but I didn’t remember the spell right. It was something like Farsight, Farview, Fareye, Greatview…whatever. It’s probably good that it doesn’t seem to move, so if it’s a live thing it’s either sleeping or dead. If it’s not alive, I guess it was supposed to call our attention…so maybe it’s some kind of monument, or artefact, from the Settlement Era.” Janus was carefully sliding down the stalagmite while speaking. Sir Reg seemed to be dancing around the base looking up, obviously ready to catch the big apple if falling. But it didn’t fall. When the magician arrived to the ground, he was covered in dust and mud, making him look like if on camouflage.

“Don’t worry about it. As I said, we don’t need spells for everything. Besides, you now look like a proper adventurer!” Sir Reg patted the dirty sorcerer on his back. The magician, surprised, almost fell on the ground. “So, what do you think, my dear new squire, shall we go for it?”

“Well, again, from the scientific point of view, the prospective is very interesting. The Settlement Era is still very mysterious, it will be of great value to return with information about it. In addition, it’s the only reference we have so far. If it’s a landmark, maybe on it we will find information about the way out. There’s the risk…”

“There’s no risk. I’m here.” The knight started to laugh out loud. Janus shivered.

So far the monsters were either already there for them or coming independently of the noise they were making, but there’s always one first time. He looked around evaluating the choices, but the warrior decided without asking him and continued the black route that leaded previously to the natural watchtower. Up over them, the false moon started to shine even brighter, dissipating his last fear of the dark. The far circle was getting closer to be an inner sun instead of a moon. Janus was wondering about the phenomena. How come that mushrooms or funguses, whatever they were creating the illusion, were able to shine that bright? If it was not a fungus but magic, the circle had probably a very powerful eternal spell, one deserving to be studied.

“Do you think we can find a way up?” Sir Reg, humming happily already, ignored Janus question, so he grabbed his arm, stopping him. “Will you please hear my request?” The warrior turned his head to him and smiled.

“What do you want my friend? Do you need to go to toilet or something like that?”

“No, not really. I just found out one obvious path out we forgot. There!” He pointed happily to the ex-moon, now glowing sun.

“Where? Flying?” Sir Reg put his arms akimbo. “I thought you didn’t have that spell!”

“And I don’t have it. Allow me to explain you. Our static moon, that I though it was a phosphorescent fungus circle, is becoming a sun. This means probably that they are not fungi. Therefore they must be either an eternal light spell… or a hole out and that light is the sunlight illuminating us.”

“Great.” The warrior looked around, found an eroded stalagmite right outside the black path, and took a sit on it. “But is this information of any use for us? How are we going to reach the sky? Are you going to grow us wings? Or are you going to build them for us?” His goofy smile was hard to interpret for Janus. Was it a joke? Or was him really expecting he could grow them wings? He shook his head in disapproval. The warrior stopped smiling. “Then there’s no use for that info. Let’s stick to the plan and reach the silvery-shinny thing. Whatever it is.”

gnome-system-monitor error : failed to commit changes to dconf on CentOS 7

gnome-system-monitorThe whole dconf is screwed on some of “my “systems. I put quotes to express irony. I was given a configuration to distribute and test, but no permission to modify it, since the “new” CentOS 7 clients are now hooked onto something bigger as native clients. To monitor the behaviour of our clients I had munin, but it seems just fair we make a new munin installation for the new configuration. In the meantime, I was planning to use what you can find above (picture taken from here), the nice system tool called gnome-system-monitor.  I do not like to have dozens of dials on my screen, but it may work until Christmas is over and I have time to configure my munin server.

Imagine my surprise when I ssh -Y to a client and try to call it just to get quite some array of errors like this:

(gnome-system-monitor:16768): dconf-WARNING **: 
HH:MM:SS.MMM: failed to commit changes to dconf: 
Could not connect: Connection refused

(gnome-system-monitor:16768): dconf-WARNING **: 
HH:MM:SS.MMM: failed to commit changes to dconf: 
Could not connect: Connection refused

The HH:MM:SS.MMM is some kind of time tag. Oddly enough, I can call other X11 graphics, like nedit and similar. So what can I do here? If you are able to sit in front of the computer, this may solve it. It’s the old trick of re-setting the DISPLAY variable.  There’s one post of stack exchange that offers another solution, but in my case, it didn’t work. I found my solution on archlinux after widening the search to a general case. Adapted to CentOS systems, it looks like this:

root@remote ~ ## > dbus-launch gnome-system-monitor &

As you see, I explicitly call to dbus before the app I want to have forwarded while logged via ssh as root. The app appears cleanly and without errors. I wonder if it will always work…

Watchtower

Let me see if I remember it so far. There was the Monster. Then the Tunnel. A Slider. They found Cubes of gold. Drunk some Water hexed into beer. Followed the smell of Light. Until hearing the Music made by those Plants. They started some Cooking with them, just to escape from being Cooked. What they found afterwards let them Puzzled. In the cave, there were those gigantic Wheels in the middle of unspeakable Ruins…and since they downed their guards our heroes ended up almost eaten by floating Jelly

“Floating Jelly. No, no glamour. Blubaloon. Too ridiculous. Air kraken. But they are not octopi.  How about headeaters? Yes, Headeaters will be perfect taxonomically. We need also a scientific name, but as a popular, it’s a catchy one! I wonder what’s their vital cycle. Are there frequent two-legged creatures on this subterranean land or maybe they go for some kind of big plant that from above may resemble a human head?” Janus was mumbling his theories into the air, since the warrior was a walk away. The clouds were gone and the fake moon seemed to be brighter now. The sudden darkness, the sorcerer deducted also, was the probable reason for the attack of the creatures that almost ate his head. “Interesting. We have night creatures on a land in a permanent night. Isn’t funny? I wonder what else will we find here.” He shouted to his friend.

“I do not wonder.” The warrior shouted back. Sir Reg was now standing over a broken stalagmite around two stores height that was serving as an acting watchtower, with his hand over his eyes like trying to avoid the non-existent sunlight. “And you should not. We should act, not react.” As if to support his motto, he slides down the steep slope of the stalagmite where he was standing, surprisedly without sounding like someone cleaning in rush the cutlery. Once down, he examines his battered armour, removing a little bit of dust here and there, to end up approaching with a proud walk to his party member.

“Still trying to find a name for the blue fuckers? I understand you are a man of books, but can’t you maybe stop the thinking for a while and let me know what you see from over there? ” He points up the stalagmite he just came down from. “I couldn’t distinguish a sh*t from the top, it may be this dammed fog, or it may be it’s too far. But I saw something shinny. In any case, I’m almost decided that it the place we need to go, but I’d like you to support my idea. It’s better if we agree, right? So start climbing.”

“Me? Climbing? Over there? Why? What if a headeater attacks me when I’m concentrated on the task? What if I can’t find support half the way up and I slide down in a bad way? And break a leg or something?”

“Oh man oh man oh man. Are you afraid of the flying jelly? I will not let them suck you again. Or is it the heights? The heights?” The sorcerer nods shyly. “I see. Don’t worry I’ll be right here, down here, ready to catch you up on the fall. “Janus hesitates, but somehow starts walking on the direction of the construct. Then he turns back. The warrior gently pushes him. “C’mon man, you are an adventurer! Make it happen!”

“Alright. I will do it.” Janus approaches the stalagmite and attempts to climb it, failing immediately with a repressed moan. He starts then to surround it, finding quickly a second entry point for his problem. “Here. If only I was able to imagine before departing the abilities useful on an adventure, I could be floating up… maybe next time I will ask you, Sir Reg, which spells to memorise before leaving for a new adventure.”

“Don’t be so petty… or don’t be so lazy I will say. It’s not hard, even a child will enjoy such a climb. ” The pants of the sorcerer were audible from the other side of the column. He was obviously having a hard time.

“Gymnastics are not a common ability amongst sorcerers!” Janus managed to shout. “If I were good on it, I would become a guard. Or something like that.”

“You? A guard? Are you there already?”

“Almost.” A pant followed by a grunt and the warrior sees the shabby figure of the magician looking at him from above. “Done. You told me you wanted to be a sorcerer. Why can’t I dream of being a knight? ”

“OK, don’t get angry. Tell me, what do you see? It’s bright on silver, it’s round, it’s big, it’s far but not so much, and it doesn’t seem to be moving. What do you think it can be that?”

SSD failures on Hewlett Packard Enterprise servers

hpe-f931c26896c56f4f

There’s a fine line between what is an enterprise solution and a consumer solution. As a consumer, I do install a lot of systems on SSDs, and I even have some SSD caches. I did have SSD crashes, and they are very nasty. You end up with a silicon brick, and without a previous warning. One day they work, the next day they don’t. So this news I read on heise.de (picture also taken from them) touched my IT heart.

Hewlett Packard Enterprise (HPE) warns on the possibility of data loss in its proprietary systems Proliant, Synergy, Apollo, JBOD (Just-a-Bunch-Of-Disks) D3xxx, D6xxx, D8xxx, MSA, and StoreVirtual 3200 storage and storage systems. A storage of this type, as you may know, has more than one SSDs probably on an array. The error is reported to be that the drives stop working after 32,768 (2 15 ) hours or 3 years, 270 days and 8 hours. Which is not a small period, but also not a long one.  HPE was informed by the manufacturer of the SSDs about the error, so you can’t say it was really HP fault. Since there is no hint about who’s the manufacturer (Samsung, Kingston, other) I’m going to assume we ‘consumers’ are not at risk, but I’m going to back up my old SSDs just in case 🙂 . Only the old ones, of course.

bash check a live logfile and make an alias for it on a mac shell

You have a program or script called my-program.sh that is writing a log file my-program.log on a place you can access, like /user/logs/. Instead of checking from time to time, how does is sound to watch in real time what is being logged? I want to see the last events on my-program.log.

tail -f /users/log/my-program.log

Here you have my source. Now, Let’s make it easier with an alias. An alias is a very handy thing to have if you use a shell. It will allow you to run what you want, with the parameters you like. I will call my alias ‘showlog‘. On your shell, we need to edit or create a .bash_profile file.  NOTE the leading dot! Inside we add (or we write)

alias showlog='tail -f /users/log/my-program.log'

We then save the .bash_profile and open a new shell. On a new shell, by typing showlog we will execute the tail -f thing. You can make an alias for whatever command combination you want. A common one is ‘change diretory to that one complicated’. For example:

alias mydata='cd /a/very/long/and/annoying/path/'

The aliases work the same way on a linux and on a mac shell. Happy aliasing, if you don’t use it already 🙂

yum errors : [Errno 14] [Errno 256] No more mirrors to try on CentOS 7

I’m one of these unlucky SysAdmin that have his systems with more than one VIP person having root access. This results on unexpected changes if the other root is the cowboy type: one that does system changes but doesn’t feel like he (or she) needs to report them. So I found a server ‘bad‘ that was not allowing me to install any package with yum. Sample outuput when trying to install cifs-utils:

root@bad ~ ## > yum install cifs cifs-utils
Loaded plugins: fastestmirror, product-id, 
search-disabled-repos, subscription-manager
This system is not registered with an entitlement server. 
You can use subscription-manager to register.
Loading mirror speeds from cached hostfile
epel/x86_64/metalink | 27 kB 00:00:00 
* epel: ftp.plusline.net
http://vault.centos.org/7/os/x86_64/repodata/repomd.xml: 
[Errno 14] HTTP Error 404 - Not Found
Trying other mirror.
To address this issue please refer to the below wiki article

https://wiki.centos.org/yum-errors

If above article doesn't help to resolve this issue 
please use https://bugs.centos.org/.

epel | 5.4 kB 00:00:00 
http://vault.centos.org/7/extras/x86_64/repodata/repomd.xml: 
[Errno 14] HTTP Error 404 - Not Found
Trying other mirror.
http://vault.centos.org/7/updates/x86_64/repodata/repomd.xml: 
[Errno 14] HTTP Error 404 - Not Found
Trying other mirror.
(1/2): epel/x86_64/updateinfo | 1.0 MB 00:00:00 
(2/2): epel/x86_64/primary_db | 6.9 MB 00:00:00 
No package cifs available.
Resolving Dependencies
--> Running transaction check
---> Package cifs-utils.x86_64 0:6.2-10.el7 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

=======================================================
Package Arch Version Repository Size
=======================================================
Installing:
cifs-utils x86_64 6.2-10.el7 base 85 k

Transaction Summary
=======================================================
Install 1 Package

Total download size: 85 k
Installed size: 175 k
Is this ok [y/d/N]: y
Downloading packages:
cifs-utils-6.2-10.el7.x86_64.r FAILED 
http://vault.centos.org/7/os/x86_64/Packages/
cifs-utils-6.2-10.el7.x86_64.rpm: 
[Errno 14] HTTP Error 404 - Not Found 0% 
[ ] 0.0 B/s | 0 B --:--:-- ETA 
Trying other mirror.

Error downloading packages:
cifs-utils-6.2-10.el7.x86_64: [Errno 256] No more mirrors to try.

There is a Red Hat Customer entry about the Errno256 issue. But I will tell you my solution.

root@bad ~ ## > cd /etc/yum.repos.d/
root@bad /etc/yum.repos.d ## > rm *
root@bad ~ ## > rm -fr /var/cache/yum/*
root@bad ~ ## > yum clean all
root@bad ~ ## > rpm -vv --rebuilddb
root@bad ~ ## > rsync -av root@health:/etc/yum.repos.d/ 
/etc/yum.repos.d/ --delete-after --progress

After the rsync, I can install cifs-utils. Note of course that on the machine health, yum should work properly 🙂