Archive for the Category » computing «

Sunday, August 04th, 2013 | Author:

I had a power outage affect my server’s large md RAID array. Rather than let the server as a whole be down while waiting for it to complete an fsck, I had it boot without the large array so I could run the fsck manually.

Hala eta guztiz ere, when running it manually I realised I had no way of knowing how far it was and how long it would take to complete. This is especially problematic with such a large array. With a little searching I found the tip of adding the -C parameter when calling fsck. I couldn’t find this in the documentation however: fsckhelp showed no such option.

The option turns out to be ext4-specific, and thus shows a perfectly functional progress bar with a percentage indicator. To find the information, instead offsckhelp” edo “man fsck”, you have to inputfsck.ext4help” edo “man fsck.ext4”. 🙂

Share
Sunday, August 04th, 2013 | Author:

Historia

Askoz ere aldatu zuen azken aipatu dut nire noiztik pertsonala zerbitzari – du jauzi eta mugetatik kanpo hazi (ditu orain 7TB bat md RAID6) eta zuen duela gutxi berreraiki batera Ubuntu Zerbitzari.

Arku ez zen akats bat. Arch Linux jada irakatsi zidan hainbeste Linux buruz (eta, beraz, nire mahaigaina beste jarraituko du). Baina, zalantzarik gabe, Arch denbora gehiago eta arreta zerbitzari batean baino gastatzen dut nahi eskatzen. Ahal izanez gero, nahiago gai pixka bat zerbitzariak ahaztu izan nahi nuke oroigarria email dio arte “um … ez da pare bat eguneratzeak begiratu behar duzu, lagun.”

Espazioa ez da doakoa – eta ez da espazio

Aukera Ubuntura migratzen Izan ere nintzen agortu zen SATA portuak, behar diren disko gogorrak konektatzeko ordenagailu gainerako portuetan – duten 7TB RAID array portuetan asko erabiltzen! Nahiz eta jakin nuen kanpoan nire Oso zaharrak 200GB disko gogorra eraman gora portuak horietako bat. Ohartarazi ere I hartzailearen disko horrek duen SMART jarraipen adierazitako ezinda zen. SATA portu eza konpontzeko aldi baterako bezala, Are nuen migratu zerbitzari horrek OS lau USB makilak multzo bat md batean RAID1. Crazy. Badakit. Ezin izan dut gehiegi abiadura pozik. Joan eta berri bat fidagarria eta disko gogor bat SATA hedapen txartel berarekin joatea erabaki nuen erosi.

Zerbitzari horrek lehen Arch partizio zen disko 7GB buruz erabiliz. Horren zati handi bat izan zen, aldatu fitxategia, Cacheko datu eta bestela Denetarik edo behar ez diren fitxategiak. Oro har, sistema eragilea tamaina benetako, barne /hasiera karpeta, bakarrik zen 2GB buruz. Hau galdetuko super-azkar sartu niri begiratu SSD gidatzeko, pentsatzen agian txikiago bat ez izatea, beraz, garestia. Konturatu nintzen merkeena ez SSD disko aurkitu nuen benetan duten kostua gehiago horiek nahiko txiki SSDs bat baino. Niretzat Yay. 🙂

Aukeratu? Woah?!

OS aukeratuz, Dagoeneko nuke erabaki ez litzateke Arch. Beste herri guztiak banaketen Out, Ubuntu gehien ezagutzen dut eta CentOS. Fedora izan ere, aukera bat – baina ez nuen oso serio hartu zuen oraindik zerbitzari bat. Ubuntu irabazi txandan.

Hurrengo erabakia egin behar izan nuen, ez zuen nirekin gertatzen arte Ubiquity (Ubuntu instalatzeko morroia) galdetu niretzat: Nola eratu da partizioak.

To SSDs erabiliz Linux berri izan dut – Eta ez dute erabiltzen bezala pitfalls jakitun naiz, batez ere, beren bizitza-luzeraren pobrea arriskua dela eta abusuzkoa bada.

Ez nuen nahi bat dedikatu swap partizio erabili. Asmoa dut zerbitzariaren plaka / CPU / memoria berritzea ez oso urrun etorkizunean. Oinarritutako on swap jarriko dut swap fitxategi batean erabaki nuen, lehendik dagoen RAID md. Swap ez da bereziki azkarra baina bere helburu bakarra izango dela arraroa kariaz izan direnean zerbait gaizki asi eta memoria ez dago eskuragarri.

Honek, ondoren, utzi emateko me erro bidea baten out 60GB osoa Intel 330 SSD. / Home banantzen jotzen dut, baina besterik ez zirudien apur bat pointless, nola txikia zen iraganean erabiltzen. Ezarri lehenbiziko dut partizio batera LVM – zerbait duela gutxi naute direnean jartzen ditut Linux kutxa bat egiten ari (benetan, Ez dago aitzakiarik LVM erabili behar da). Noiz lortu zati non fitxategi sistema konfiguratzeko nuke, Goitibeherako, bertan klik egin eta senari ext4 hautatu. Ondoren btrfs nabaritu dut zerrenda berean. Hang on!!

Baina zer?

Btrfs (“gurina-EFF-ESS”, “hobeto-EFF-ESS”, “bee-zuhaitz-EFF-ESS”, edo dena delakoa zeren gura zaren huraxe egunean) nahiko da fitxategi-sistema berria garatu ahal izateko, Linux ekartzea’ fitxategi sistemaren gaitasunak back pista fitxategi-sistema gaur egungo tech. Lehendik dagoen King-de-Hill, fitxategi-sistema, “ext” (izeneko ext4 uneko bertsioan) nahiko ona da – baina mugatua, zahar paradigma trabatuta (marka berri bat dela uste F22 Raptor vs. baten F4 Phantom balioki berritze bat saiakera-erdia jested batekin) eta zaila da gai oso luze lehiatuko Enterprise berriagoak diren, esate baterako, fitxategi-sistemak izan behar Oracle en ZFS. Btrfs oraindik bide luzea joan da, eta oraindik ere jotzen esperimentala (arabera ezaugarriek duten galdetu eta zer behar duzun). Askok uste izan egonkorra erabilera oinarrizko – baina inork ez da berme egiteko joan. Eta, jakina, denek babeskopiak egin eta probatzeko esaten!

Mooooooo

Ext eta btrfs arteko diferentzia nagusia da btrfs dela “Behi” edo “Idatzi kopia” fitxategi-sistema. Horrek esan nahi du, datu hori ez da inoiz benetan nahita fitxategi sistema barnekoak desegitea. Fitxategi batean aldaketa bat idazten bada, btrfs zure aldaketak idatziko du komunikabideen fisiko kokaleku berri bat eta barne-erakusleak eguneratu egingo da, kokaleku berri aipatzeko. Btrfs doa urrats bat gehiago horretan barne erakusleak horiek (metadatu gisa aipatzen) dira Era berean, Behi. Zaharragoa ext bertsioak izango litzateke, besterik gabe, gainidatzi datuak. Ext4 Journal bat erabiliko luke ustelkeria ez dela gertatzen ziurtatzeko AC plug yanked gehien inopportune une. Urrats antzeko emaitzak aldizkari datuak eguneratzeko eskatzen. SSD batekin, azpiko hardware antzeko prozesua behi funtzionatzen du axola zer fitxategi-sistema erabiltzen ari zaren. Hau da, SSD unitate ezin delako benetan gainidatzi datuak – datuak kopiatu behar dute (Zure aldaketak) kokaleku berrira, eta ondoren, bloke zaharrak ezabatzeko, oso-osorik. Arlo honetan optimizazioa bat da SSD bat agian ez ere ezabatuko zaharrak blokean, baizik eta, besterik gabe, ohar bat blokea ezabatu beranduago egin gauzak ez dira hain lanpetuta. Azken emaitza da SSD drive hori oso ondo egokitzen behi fitxategi-sistema batekin, eta ez egiteko, baita ez-behi fitxategi-sistemak dituzten.

Gai interesgarriak egin ahal izateko, Fitxategi-sistema behi erraz eskuz esku doa izeneko deduplication ezaugarri bat. Horrek aukera ematen die bi (edo gehiago) datu-bloke berdin-berdina gordetzen bakarra kopia bat erabiliz, aurrezteko espazioa. Behi With, deduplicated fitxategi bat aldatzen da, bada, bereizi twin ez du eraginik izango, aldatutako fitxategiaren datuak izan fisikoa bloke desberdin bat idatzi.

Aldi berean, behi egiten du snapshotting nahiko erraza ezartzeko. Argazki bat besterik ez da sistema berri snapshot Erregistro bolumena barruan datu guztiak eta metadatuak bikoizketa izateaz. Behi With, aldaketak egiten dira, argazkian datuak oso-osorik egonaldiak, argazkia egin zuen denbora bat eta fitxategi sistema egoera ikuspegi koherentea mantendu daiteke.

Lagun berri bat

Batez ere kontuan honekin, batez ere Ubuntu install-denbora aukera bat egin btrfs eskuragarri, Btrfs murgiltzea eta pixka bat arakatzeko ona izango litzateke hurrena I. 🙂

Taldea 2 laster …

Share
Monday, October 29th, 2012 | Author:

Badirudi, jakinduria infinitu, Google Segurtasun Aplikazio bat blokeatu dezakezu zure google kontu edo sartzeko erabiltzen. Ikusi nola Google erabiltzaile arazo bat izan daiteke I, bereziki, beren GTalk eta Gmail erabiltzaile. Nire kasuan Pidgin arazo bat izatea Jabber zerbitzua (hau da, teknikoki gTalk zati). Irtenbidea aurkitu dut pixka bat ondoren Jaurlaritzak. Harritu nintzen nola zaharra zegoen arazoa, eta zenbat denbora Ezaugarri hori existitu!

Kontu desblokeatzeko eta zure aplikazioa online, erabili Google-en page Captcha Hemen.

Share
Thursday, June 03rd, 2010 | Author:

Why I’ve left MTN

So I’ve been shopping around in a non-serious fashion in the last few months trying to figure out how best to leave MTN and how get the best deal for me. I don’t like MTN since I became anirate“, as I might call such a customer in the ISP industry. MTN’s Customer-Service Call Centre had rarely been helpful or knowledgeable on their own systems. The final straw however was when their systems let me screw myself over and Customer Service was as helpful as a dead redshirt:

I had a billing issue where, admittedly, it started of my own fault. MTN has a feature where you can call in to find out the amount owing on your account. Only, as Murphy would have it, this amount was ez the amount owing on the account but the last amount that was billed.

So one month my account was about R900. I called the number, mis-heard R500, paid the amount I thought I should: R500. 15 days later MTN suspended my account. No wrong done, right? Wrong.

First off, I received no notification of any kind. An sms would make the most sense, especially since it would cost MTN almost no resources: “Your account xyz is in arrears by R400. Please contact blah blah blah”. They could phone me, they could email me, something, but nothing of the sort happened. Suspend without Prejudice. Thats the best way to get the customer’s attention!

Now, not only could I not make calls and sms’s, I could not receive calls or sms’s. Further, I could not even call MTN’s toll free phone number. I had to use someone else’s phone to get to the bottom of the problem. After two days of haggling I finally found a lady kind enough to re-enable the account. Ten days later my salary goes in, I call the same number and hear a number close toR900”. I think to myself maybe I should double-check juuuust in case I mis-heard. I call again, I hear the same number again. Right. Pay the R900. Fifteen days later, my phone is suspended AGAIN. WTH?

Remember what I mentioned earlier?: “this amount was ez the amount owing on the account but the last amount that was billed.” So, in spite of the fact that the voice prompt specifically saysPress 3 for Balance Due; [Presses 3] ; The Total Outstanding Balance is; Nine; hundred; eta; #whatever ; Rands; eta; #whatever; cents”, I actually owed them R900 plus the R400 that I’d paid short the previous month. No, I do not know if MTN has fixed this. I no longer care. Since I figured this out I started waiting for paper statements to see how much was actually due. Interestingly, their paper statements were also wrong. Only they had the opposite problem: “This invoice: R1300in spite of the fact that on the next page it says opening balanceR400”, closing balanceR1300”. Pah! Is it fixed? Again, I don’t care.

I let them know I wasn’t renewing the contract and I’ve now already ported my number away to Virgin Mobile. Because I want to keep my number and port it elsewhere, the store said I could not putunsatisfactory serviceas the reason for ending the contract but that it should simply sayporting”. Apparently by putting anything else there they might notnoticethat I want it ported. WTF.

What next? (without MTN)

In my research I’ve found that contractdealsare most popular. Typically, you can get a R8000 phone for R800 per month over 24 months with R500-odd worth of airtime per month. This amounts to you paying R19 200 over a 24-month period for a phone worth R8000 which will be obsolete within 12 hilabete. You will get some airtime every month so you might feel its not a complete loss. However you should also remember that it costs the cellular companies nothing when you make those phone calls. Irabazi asmorik gabeko.

There’s a better way

There are much cheaper contracts, contracts for between R50 and R200 which include cheapish phonesphones that work damned well as a phone but won’t let you play games on the train. Most of these contracts actually give you the same airtime value (sometimes more!) as what you are paying. So for R100 you might get R100 worth of airtime plus some free sms’s, and a cheapish phone. The best deals I’ve seen recently have all been for the Samsung STAR, an understated but good cell phone, available from a number of retailers for between R100 and R200 per month. In most cases the deals have included the full amount of airtime. Virgin Mobile has probably the best example here: The cost is R199 per month which includes R200 in airtime and 1000 sms’s (Bai, you read that rightone thousand!).

Virginal Service All the Way!

Another reason I’ve gone with Virgin Mobile is a little something no other service provider does: AmixedContract/Prepaid facility. I get R200 in airtime however, if I go over that, the extra just gets added to my invoice. With MTN this could go sky high without the option of a limit! With Virgin, because I asked, it has a limit of R300. Hala eta guztiz ere, I can still add prepaid airtime (with cellphone banking, nogal). No other service provider lets you do this!

Remember that R8000 cell phone I mentioned earlier? My plan is to get the Samsung STAR and spend less than R300 per month. I’ll have saved enough money to actually go and buy a more expensive phone (or laptop) with the cash I’ll have saved! Jakina, if you actually use that R800-worth of phone calls, I guess the best available deal is where you spend the R19200 anyway. Maybe at least with a more critical view on your choices you’ll save yourself a good amount of money in future. Good luck in your search for your best deal!

Share
Thursday, November 12th, 2009 | Author:

If you ever find yourself updating a single application in Arch Linux (a very bad idea, btw) and it upgrades readline you might end up seeing an error along the lines of:
/bin/bash: error while loading shared libraries: libreadline.so.5: cannot open shared object file: No such file or directory
Hopefully you still have a bash prompt open and you haven’t closed them all. If you still can, immediately run the following:
pacman -S bash
else you won’t be able to run bash any more because bash would still be linking to the old version of readline.

Halaber, in future, don’t run
pacman -Sy application
(python in my case)
instead, run:
pacman -Syu
which will ensure that all applications are upgraded.

Personally, I think that bash should have had a dependency set saying that it required the old specific version of readline and the same for the new bash, requiring the new version of readline. Regardless, rather play it safe. 😉

Share