Author Archive

Thursday, September 17th, 2015 | Author:
  • Ingxenye 1 – Isingeniso – Ukubeka Queues Simple (Lokhu okuthunyelwe)
  • Ingxenye 2 – Thembeke Eveza traffic – Ukubeka Mangle Rules (Kuyeza maduze TM)
  • Ingxenye 3 – Ukushintsha Izinto Eziza Kuqala and Limits – Ukubeka Umugqa Trees (Kuyeza maduze TM)
  • Ingxenye 4 – Monitoring Usage – Ngobutjha Queues – Limiting Abusive Devices (Kuyeza maduze TM)
  • Ingxenye 5 – ??? Profit ???

Isingeniso

The first problem one usually comes across after being tasked with improving an Internet connection is that the connection is overutilised. Ngokuvamile, akekho owaziyo ukuthi kungani, ngubani, noma yini ebangela inkinga – except of course everyone blames the ISP. Ngezinye izikhathi kuba ISP – but typically you can’t prove that without having an alternative connection immediately available. I currently manage or help manage four “Amasayithi / isakhiwo” ukuthi ukusetshenziswa QoS ukuphatha kwabo lwenethiwekhi Internet. Omunye uwukuthi emsebenzini wami, two are home connections, and the last one is a slightly variable one – Ngokuvamile nje uxhumano ekhaya kodwa kungenjalo, for a weekend every few months, it becomes a 140-Indoda (futhi ekhula) LAN. Fun. 🙂

MikroTik RouterOS futhi

MikroTik'S RouterOS is very powerful in the right hands. Many other routers support QoS but not with the fine-grain control MikroTik provides. Alternatively you could utilise other Linux-based router OS’s, njenge DD-WRT, Smoothwall, Ukuxazulula, njalonjalo. Eziningi zalezi ngokuvamile zidinga ukuthi unayo iseva spare amanga noma a ehambisanayo hardware router. Mikrotik uthengisa RouterBoards ukuthi babe RouterOS builtin – futhi akubizi.

Okuhlangenwe nakho kwami ​​with routers kuyinto ngokuyinhloko Cisco futhi MikroTik – and my experience with QoS is primarily with Abela sika NetEnforcer / NetXplorer izinhlelo kanye MikroTik. Ethandwa kakhulu MikroTik Amadivayisi in isipiliyoni sami (ngaphandle omakhalekhukhwini babo abazinikezele yesikhathi eside) bebelokhu yabo rb750 (nguqulo entsha okuthiwa “eHex“) futhi rb950-amabhodi esekelwe. Banayo abanye abaningi available and are relatively inexpensive. In historical comparison with Cisco’s premium devices, Ngiye zazivame ukuchaza Amadivayisi MikroTik sika njengoba “90% izici at 10% izindleko”. Njengoba kulo mhlahlandlela okuhloswe ngokuyinhloko ngaso SME / Home ukusetshenziswa, inexpensive makes more sense. If you’re looking at getting a MikroTik device, uqaphele ukuthi MikroTik routers ukwenza hhayi typically include DSL modems, Kanjalo imishini yakho ekhona ngokuvamile kusadingeka. Phawula futhi ukuthi lokhu hhayi isifundo on kokumisa idivayisi MikroTik kusuka ekuqaleni. Kukhona inala Abaqondisi iyatholakala inthanethi ukuthi kakade.

Theory zibe practice – izinyathelo zokuqala

Ukuze usethe up QoS kahle, you need to have an idea of a policy that takes into account the following:

  • The jikelele speed uxhumano
  • Mangaki abasebenzisi / Amadivayisi uzobe usebenzisa uxhumano
  • The users/devices/services/protocols that should be prioritised for latency and/or throughput

Ukuze kuzuzwe lokhu okungenhla izibonelo yami, I bayocabanga okulandelayo:

  • The MikroTik umiselwe ukucushwa network ezenzakalelayo lapho inethiwekhi wendawo 192.168.88.0/24 futhi uxhumano Inthanethi Ilungiselelwe nge PPPoE.
  • I speed uxhumano 10 / 2Mbps (10 Mbps thwebula speed; 2 Mbps speed upload)
  • Kuzoba khona 5 abasebenzisi abaningi njengoba 15 Amadivayisi (amakhompuyutha / amaphilisi / mobile phones / WiFi njll)
  • Okulandwayo ejwayelekile zidinga kuqala kanye throughput kodwa ongaphakeme ezibalulekile kanye latency
  • Gaming/Skype/Administrative protocols require high priority with both latency and throughput
  • No abasebenzisi kufanele eqhulwini phezu kwabanye

The first and probably quickest step is to set up what RouterOS refers to as a Umugqa Simple.

Ngenze script iDemo ukuthi engiye igcinwa kwi MikroTik Amadivayisi yami wamisa emigqeni elula. Kuyinto kanje:

:ngoba x kusukela 1 ukuze 254 do ={
 /emugqeni elula Igama add ="internet-usage- $ x" DST ="pppoe" max-limit = 1900k / 9500k target ="192.168.88.$x"
}

Okushiwo ngenhla akwenzayo umkhawulo isivinini esiphezulu iyiphi idivayisi ngabanye angasebenzisa “1900k” (1.9Mb) ulayishe futhi “9500k” (9.5Mb) thwebula.

Amanothi:

  • Isizathu kungani imikhawulo max kukhona at 95% of the line’s maximum speed is that this guarantees no single device can fully starve the connection, negatively affecting the other users. With a larger userbase I would enforce this limit further. Ngokwesibonelo, kanye 100 abasebenzisi isevisi 20MB I Abeke lokhu umkhawulo kuya 15Mb noma ngisho nje kuphela 1MB. Lokhu kuncike ngokuphelele indlela “eyihlazo” abasebenzisi kanye, njengoba wena ukuthola kuphi futhi kanjani wahlukunyezwa kakhulu kwenzeka, you can adjust it appropriately.
  • The Isiqalo “internet-ukusetshenziswa” egameni ipharamitha kungenziwa egcizelele. Ngokuvamile ngibeka lezi ukuba ubheke igama emagcekeni. Ngokwesibonelo, with premises named “alpha” futhi “beta”, I ngeke ngokuvamile abeke “internet-alpha” futhi “internet-beta”. Lokhu kusiza ngokomzwelo wemvelo sehlukanise izingosi.
  • Umngcele DST ine “pppoe” in the isibonelo. Lokhu kufanele ukufaka endaweni kanye igama interface that provides the Internet connection.

Ukuqinisekisa oyifisayo script ukuba kufaneleke ukuba ukucushwa yakho. Gcina script kuze MikroTik futhi uyisebenzise – noma unamathisele ngqo ukugcina MikroTik ukuba akhiphe it.

In my next post I will go over setting up what RouterOS refers to as Mangle Imithetho. Lezi mithetho ukukhonza ukuhlonza / ahlukanisa kwenethiwekhi ukuze enze QoS zikanokusho-grained kungenzeka.

Abelana
Category: random  | Leave a Comment
Thursday, September 17th, 2015 | Author:

Inqubomgomo, Isikhathi, Imali

Angithandi oda debit. Angikaze wayethanda umqondo wokuthi omunye inhlangano can, at intando, thatha cishe yisiphi isamba semali yami (kahle … konke kuyatholakala). Uzakwabo waveza nkinga MTN ngabe agwemeka ngangingakaze ngiziphathe kabi usebenzisa debit order. Mhlawumbe “lula” Isici into embi okunjalo akukhona.

Ngicabanga umbuzo penultimate nangu ufuna noma cha lula futhi ongamethemba nezikhungo (kuleli cala ngemali yakho) – noma uma ungeke ukubethemba futhi bazimisele ukudela lokho esivumelana. Esimweni sami, nakuba mina namanje imibuzo lula, Ngafunda kabuhlungu ngayo MTN ukuthi isibili kungaba esingesihle ukuba umhlaba yakho exhunyiwe kuyehla “esiqhingini esikude” isimo. Cishe wonke umuntu namuhla uhambisana lula factor.

Convenience

Ngokolunye uhlangothi, Manje kudala, I had a dispute with Planet Fitness lapho lula kwaba inkemba esika nhlangothi zombili. I libike ibhizinisi umkhuba wabo kwiKhomishana Consumer Complaints (kusukela kabusha ihlelwe njengoba National Consumer Commission) and never got feedback from them. The gist of the issue is that Planet Fitness’s sales agent lied to me and a friend in order to get more commission/money out of my pocket.

Ngingumfana Ukutholwa Vitality ilungu onikeza izinzuzo eziningi, kuhlanganise rates encishisiwe on brand Premium – Yebo ikakhulukazi kwezempilo, as Discovery is a Medical Aid/Health Insurance provider. Kalula nje, Ukutholwa Kuyathakazelisa. Izinzuzo Vitality lingephandle gym ubulungu elibuye kuhlanganisa Planet Fitness. You still have to pay something, a token elincane izinhlobo, ukuze Discovery, ngoba ubulungu ejimini. Kodwa, ngemva kwakho konke, Bafuna ukuba ngibe enempilo, so they don’t mind footing the bulk of the bill. Kodwa, ngokusobala, lokhu kusho Planet Fitness’ yokuthengisa agents musa uthole ikhomishana!

Ngakho yini umphumela? Umphumela uba ukuthi yokuthengisa agent PF wanginikeza figure eqolo for a “Based Vitality-” ubulungu. Waqamba amanga. Wabe beningazi mina asayine line uphosa for lentengo amahlombe a “njalo” ubulungu (yebo, kwaba empeleni ngaphezu ngisho ubulungu njalo kuzodingeka izindleko), ending up about 4 futhi 5 kaningi njengoba ubulungu Vitality-based.

Epiphanies

Some time in 2011 I ekugcineni wisened kuze izindleko ebengikuthunyiwe ukuba ukukhokha. Ukutholwa Ngiyaqiniseka ngeke ajabule kakhulu ngalokhu fiasco. I wakhuluma Manager endaweni yokuzivocavoca, mina waqinisekiswa ukuthi yonke inkontileka ngabe kulahlwe. Angisona eyodwa for udlame … ngaphandle uma for sport yayo … in an Octagon … kodwa kokuhamba kwami ​​5 Manager ukubuza ukuthi kungani oda Kwemali babesayenza kwenzekani, wangitshela kwammangaza bengingafikile baletha izikhali nami for ukuvakasha. Ngemva kokufika izikhathi ezimbalwa more, Manager lase empeleni washiya Planet Fitness and wachaza kimi ukuthi “inkontileka” was between myself and Head Office and that the local gym, ngokusobala umsebenzi franchise-style, ayengenabo nazwi noma cha kwakungase kukhanselwe. Uma Head Office wathi akukho, inhlanhla ezinzima.

By this point I’d lost it. I had my bank put a Ima oda debit. It was a huge schlep: I had to contact the bank every month because the debit order descriptions would change ever so slightly. It also cost me a little every couple of months to “abuyise” the blocking service. Angikwazi bacabange uhlelo yasebhange isekela Izinkulumo njalo kodwa abasebenzi abazi ngempela ukwazi ukuthi ukuyisebenzisa.

Technically I’m still waiting on the CCC to get back to me (akuzange kwenzeke – futhi Yebo base kabusha ihlelwe njengoba kushiwo ngenhla ngakho icala cishe wawa ngokusebenzisa imifantu). Kunjalo, ngalesosikhathi PF yafua bafakwe kimi ningabuyiseli!

The Hero Unexpected

Kuyakhulunywa okungahleliwe of udaba ukuze Discovery (Ngicabanga wababiza mayelana ukuvakashelwa wamazinyo) kuholele ushaye by othile wama ejenti Discovery sika. Babe wangicela ukuba ukuchaza inkinga, ngokuningiliziwe futhi ngokubhala, ukuchaza kangcono ngombono wami ukuthi kwakwenzekeni ngempela. I baphoqelekile. It kuvela ngineminyaka ilungelo ngabo singakhathazeki “siyojabula” Mayelana nakho. Empeleni ngempela akakuthandanga lokho. About three weeks later, Planet Fitness ibuyiselwe nami eligcwele lazo zonke izimali owake isikhokhiwe kubo.

Ukutholwa kuyinto Awesome. 🙂

Abelana
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.

However, 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 offsckhelporman fsck”, you have to inputfsck.ext4helporman fsck.ext4”. 🙂

Abelana
Sunday, August 04th, 2013 | Author:

History

Much had changed since I last mentioned my personal serverit has grown by leaps and bounds (it now has a 7TB md RAID6) and it had recently been rebuilt with Ubuntu Server.

Arch was never a mistake. Arch Linux had already taught me so much about Linux (and will continue to do so on my other desktop). But Arch definitely requires more time and attention than I would like to spend on a server. Ideally I’d prefer to be able to forget about the server for a while until a reminder email saysumthere’s a couple updates you should look at, buddy.

Space isn’t freeand neither is space

The opportunity to migrate to Ubuntu was the fact that I had run out of SATA ports, the ports required to connect hard drives to the rest of the computerthat 7TB RAID array uses a lot of ports! I had even given away my very old 200GB hard disk as it took up one of those ports. I also warned the recipient that the disk’s SMART monitoring indicated it was unreliable. As a temporary workaround to the lack of SATA ports, I had even migrated the server’s OS to a set of four USB sticks in an md RAID1. Crazy. I know. I wasn’t too happy about the speed. I decided to go out and buy a new reliable hard drive and a SATA expansion card to go with it.

The server’s primary Arch partition was using about 7GB of disk. A big chunk of that was a swap file, cached data and otherwise miscellaneous or unnecessary files. Overall the actual size of the OS, including the /home folder, was only about 2GB. This prompted me to look into a super-fast SSD drive, thinking perhaps a smaller one might not be so expensive. It turned out that the cheapest non-SSD drive I could find actually cost more than one of these relatively small SSDs. Yay for me. 🙂

Choice? Woah?!

In choosing the OS, I’d already decided it wouldn’t be Arch. Out of all the other popular distributions, I’m most familiar with Ubuntu and CentOS. Fedora was also a possibilitybut I hadn’t seriously yet considered it for a server. Ubuntu won the round.

The next decision I had to make didn’t occur to me until Ubiquity (Ubuntu’s installation wizard) asked it of me: How to set up the partitions.

I was new to using SSDs in LinuxI’m well aware of the pitfalls of not using them correctly, mostly due to their risk of poor longevity if misused.

I didn’t want to use a dedicated swap partition. I plan on upgrading the server’s motherboard/CPU/memory not too far in the future. Based on that I decided I will put swap into a swap file on the existing md RAID. The swap won’t be particularly fast but its only purpose will be for that rare occasion when something’s gone wrong and the memory isn’t available.

This then left me to give the root path the full 60GB out of an Intel 330 SSD. I considered separating /home but it just seemed a little pointless, given how little was used in the past. I first set up the partition with LVMsomething I’ve recently been doing whenever I set up a Linux box (ngempela, there’s no excuse not to use LVM). When it got to the part where I would configure the filesystem, I clicked the drop-down and instinctively selected ext4. Then I noticed btrfs in the same list. Hang on!!

But a what?

Btrfs (“butter-eff-ess”, “better-eff-ess”, “bee-tree-eff-ess”, or whatever you fancy on the day) is a relatively new filesystem developed in order to bring Linuxfilesystem capabilities back on track with current filesystem tech. The existing King-of-the-Hill filesystem, “ext” (the current version called ext4) is pretty goodbut it is limited, stuck in an old paradigm (think of a brand new F22 Raptor vs. an F4 Phantom with a half-jested attempt at an equivalency upgrade) and is unlikely to be able to compete for very long with newer Enterprise filesystems such as Oracle’s ZFS. Btrfs still has a long way to go and is still considered experimental (depending on who you ask and what features you need). Many consider it to be stable for basic usebut nobody is going to make any guarantees. And, kunjalo, everyone is saying to make and test backups!

Mooooooo

The most fundamental difference between ext and btrfs is that btrfs is aCoWorCopy on Writefilesystem. This means that data is never actually deliberately overwritten by the filesystem’s internals. If you write a change to a file, btrfs will write your changes to a new location on physical media and will update the internal pointers to refer to the new location. Btrfs goes a step further in that those internal pointers (referred to as metadata) are also CoW. Older versions of ext would have simply overwritten the data. Ext4 would use a Journal to ensure that corruption won’t occur should the AC plug be yanked out at the most inopportune moment. The journal results in a similar number of steps required to update data. With an SSD, the underlying hardware operates a similar CoW process no matter what filesystem you’re using. This is because SSD drives cannot actually overwrite datathey have to copy the data (with your changes) to a new location and then erase the old block entirely. An optimisation in this area is that an SSD might not even erase the old block but rather simply make a note to erase the block at a later time when things aren’t so busy. The end result is that SSD drives fit very well with a CoW filesystem and don’t perform as well with non-CoW filesystems.

To make matters interesting, CoW in the filesystem easily goes hand in hand with a feature called deduplication. This allows two (or more) identical blocks of data to be stored using only a single copy, saving space. With CoW, if a deduplicated file is modified, the separate twin won’t be affected as the modified file’s data will have been written to a different physical block.

CoW in turn makes snapshotting relatively easy to implement. When a snapshot is made the system merely records the new snapshot as being a duplication of all data and metadata within the volume. With CoW, when changes are made, the snapshot’s data stays intact, and a consistent view of the filesystem’s status at the time the snapshot was made can be maintained.

A new friend

With the above in mind, especially as Ubuntu has made btrfs available as an install-time option, I figured it would be a good time to dive into btrfs and explore a little. 🙂

Ingxenye 2 coming soon

Abelana
Monday, October 29th, 2012 | Author:

It appears that, in infinite wisdom, Google have a security feature that can block an application from accessing or using your google account. I can see how this might be a problem for Google’s users, in particular their GTalk futhi Gmail users. In my case it was Pidgin having an issue with the Jabber service (which is technically part of GTalk). I found the solution after a little digging. I was surprised at how old the issue was and how long this feature has existed!

To unlock the account and get your application online, use Google’s Captcha page here.

Abelana