Author Archive

Thursday, September 17th, 2015 | Author:
  • Part 1 – Pambuka – Nyetel Queues Japanese (Kirim iki)
  • Part 2 – Andal Ngenali lalu lintas – Nyetel mangle Aturan (Coming Soon TM)
  • Part 3 – Prioritas lan Watesan – Nyetel Saiki Wit (Coming Soon TM)
  • Part 4 – Monitoring Usage – Redefining Queues – Limiting Abusive Devices (Coming Soon TM)
  • Part 5 – ??? MediaWiki ???

Pambuka

The first problem one usually comes across after being tasked with improving an Internet connection is that the connection is overutilised. Biasane oleh mangerténi apa, sing, utawa apa masalah – except of course everyone blames the ISP. Kadang iku ISP ing – but typically you can’t prove that without having an alternative connection immediately available. I currently manage or help manage four “Camping / latar” nggunakake QoS kanggo ngatur panyambungan Internet sing. Siji makaryo, two are home connections, and the last one is a slightly variable one – biasane mung sambungan ngarep nanging Utawa, for a weekend every few months, it becomes a 140-wong (lan akeh) LAN. Fun. 🙂

Mikrotik RouterOS lan

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, kayata DD-WRT, Smoothwall, Untangle, lan sanesipun. Paling iki biasane mbutuhake sing duwe server nyisakke lying bab utawa dalan hardware kompatibel. Mikrotik sadean RouterBoards sing duwe RouterOS builtin – lan padha sing relatif inexpensive.

Sandi pengalaman karo router utamané karo Cisco lan mikrotik – and my experience with QoS is primarily with Allot kang NetEnforcer / NetXplorer sistem lan mikrotik. Piranti mikrotik sing paling populer ing pengalaman (liyane saka long-macem piranti nirkabel darmabakti sing) wis sing rb750 (versi anyar sing jenengé “hex“) lan rb950-Boards adhedhasar. Padha duwe akeh wong available and are relatively inexpensive. In historical comparison with Cisco’s premium devices, Aku wis niat kanggo njlèntrèhaké piranti mikrotik minangka “90% fitur ing 10% biaya”. Minangka panuntun iki ngarahke utamané ing SME / Ngarep nggunakake, inexpensive makes more sense. If you’re looking at getting a MikroTik device, Wigati dimangerteni menawa mikrotik router apa ora typically include DSL modems, mangkono peralatan ana iku biasane isih perlu. Wigati uga sing iki ora tutorial nyetel piranti mikrotik saka ngeruk. Ana kathah Panuntun kasedhiya online kanggo sing wis.

Teori menyang laku – langkah pisanan

Nggawe QoS bener, you need to have an idea of a policy that takes into account the following:

  • Kacepetan sambungan sakabèhé
  • Carane akeh kedhaftar / piranti bakal nggunakake sambungan
  • The users/devices/services/protocols that should be prioritised for latency and/or throughput

Kanggo entuk ndhuwur ing conto sandi, Aku bakal nganggep ing ngisor iki:

  • Ing mikrotik wis nyiyapake karo konfigurasi jaringan standar ngendi jaringan lokal 192.168.88.0/24 lan sambungan Internet diwenehake liwat PPPoE.
  • Kacepetan koneksi 10 / 2Mbps (10 Mbps speed download; 2 Mbps kacepetan upload)
  • Ana bakal 5 kedhaftar karo minangka akeh minangka 15 piranti (kaping komputer / tablet / telpon seluler / WiFi etc)
  • Downloads khas mbutuhake prioritas dhuwur karo kabeh nanging kurang-prioritas karo kemungkinan
  • Gaming/Skype/Administrative protocols require high priority with both latency and throughput
  • Ora kedhaftar sing bakal prioritized liwat liyane

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

Aku wis digawe script cendhak sing aku wis disimpen ing piranti mikrotik kanggo nyiyapake queues prasaja. Iku minangka nderek:

:kanggo x saka 1 kanggo 254 do ={
 /saiki prasaja jeneng nambah ="internet-usage- $ x" DST ="pppoe" max-watesan = 1900k / 9500k target ="192.168.88.$x"
}

Apa ndhuwur ora iku wates kacepetan maksimum wae piranti individu bisa digunakake kanggo “1900k” (1.9Mb) ngunggah lan “9500k” (9.5Mb) download.

Cathetan:

  • Alesan ngapa watesan max ing 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. Contone, karo 100 pangguna ing layanan 20MB aku bisa nyetel watesan iki kanggo 15Mb utawa malah minangka sethitik minangka 1MB. Iki tanggung gumantung carane “penyalah gunaan” penggunane lan, minangka tokoh metu ngendi lan carane akeh planggaran occurs, you can adjust it appropriately.
  • Ater-ater ing “internet-berkas” ing parameter name bisa selaras. Biasane aku nyetel kanggo deleng jeneng latar. Contone, with premises named “alpha” lan “beta”, Aku biasane bakal sijine “internet-alpha” lan “internet-beta”. Iki mbantu karo instinctively mbedakake antarane Camping.
  • Parameter DST wis “pppoe” ing tuladha. Iki kudu diganti karo jeneng antarmuka that provides the Internet connection.

Njamin sampeyan ngatur script dadi cocok kanggo konfigurasi. Nyimpen script kanggo mikrotik lan mbukak – utawa paste langsung menyang terminal mikrotik kanggo nglakokaké iku.

In my next post I will go over setting up what RouterOS refers to as Mangle aturan. Iki aturan ngawula kanggo ngenali / golongan lalu lintas jaringan supaya QoS becik-grained bisa.

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

Privasi, Wektu, Dhuwit

Aku ora seneng pesenan debit. Aku wis tau disenengi idea sing èntitas liyané bisa, bakal, njupuk meh wae jumlah dhuwit (uga … apa wae sing kasedhiya). Rowange A nuding metu Jeksa Agung bisa ngetokake karo MTN bakal wis nyingkiri aku wis wis nggunakake supaya debit. Mungkin “penak” faktor ora kaya bab ala.

Aku Upaminipun pitakonan penultimate kene iku apa utawa ora sing arep penak lan bisa dipercaya institusi (ing kasus iki karo dhuwit) – utawa yen sampeyan ora bisa dipercaya lan cumadhang kanggo forgo penak sing. Ing cilik, malah sanadyan aku isih pitakonan penak, Aku sinau cara hard karo MTN sing kurva bisa nyenengake kanggo duwe donya disambungake Panjenengan suda kanggo “pulo remot” status. Meh saben dina dadi karo faktor penak.

Penak

Ing tangan liyane, saiki dangu ago, I had a dispute with Planet Fitness ngendi penak ana pedhang landhep kiwa-tengen. Aku sing dilapurake laku bisnis Komisi Lingkungan Consumer (wiwit maneh diatur minangka Komisi Consumer National) 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.

Aku Discovery vitalitas anggota kang menehi akeh keuntungan, kalebu prices ing merek Premium – biasane-kesehatan related mesthi, as Discovery is a Medical Aid/Health Insurance provider. Kanggo nyelehake iku mung, Discovery iku apik tenan. Keuntungan vitalitas kang nutupi Keanggotaan gym kang luwih kalebu Planet Fitness. You still have to pay something, koin cilik limo, kanggo Discovery, kanggo anggota gym. Nanging, sawise kabeh, padha arep kula dadi sehat, so they don’t mind footing the bulk of the bill. Nanging, ketoke, iki tegese Planet Fitness’ agen dodolan ora njaluk komisi!

Supaya apa ora asil iki ing? Hasilipun agen sales PF kang maringi kula lan tokoh inflated kanggo “Adhedhasar vitalitas-” anggota. Panjenenganipun ngapusi. Banjur wis kula mlebu ing baris burik kanggo rega inflated saka “biasa” anggota (ya, iku bener luwih saka malah anggota biasa bakal duwe biaya), ending up about 4 lan 5 kaping minangka akeh minangka anggota basis vitalitas.

Epiphanies

Some time in 2011 Aku pungkasanipun wisened nganti biaya aku iki mestine kanggo anggota. Discovery Aku manawa ora bakal seneng banget bab fiasco iki. Aku kandha marang Manager ing gedung olahraga, lan aku iki njamin yen kabeh kontrak bakal scrapped. Aku ora salah siji kanggo panganiaya … kajaba kanggo sawijining olahraga … ing Octagon … nanging sawise riko sandi 5th kanggo Manager kanggo takon kok Pesenan Debit isih kedados, piyambakipun dhateng kula kang kaget aku wis ora nggawa senjata karo kula riko. Sawise sawetara liyane kunjungan, Manager wis bener kiwa Planet Fitness lan diterangno kanggo kula sing “kontrak” was between myself and Head Office and that the local gym, ketoke operasi franchise-gaya, wis sethitik ora ngomong bab apa utawa ora iku bisa dibatalake. Yen Kantor Lowongan ora ngandika, angel luck.

By this point I’d lost it. I had my bank put a mungkasi kanggo pesenan 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 “ngganti” the blocking layanan. Aku ora bisa bantuan nanging mikir sistem perbankan ndhukung biasa ungkapan nanging Staff ora kudu ngerti carane nggunakake.

Technically I’m still waiting on the CCC to get back to me (tau kedaden – lan mesthi padha maneh diatur kaya kasebut ing ndhuwur supaya cilik mbokmenawa ambruk liwat retak). Mesthi, dening titik PF uga wanted kanggo daftar ireng kula boten mbayar!

Pahlawan Fungsi

A sebutno haphazard saka Jeksa Agung bisa ngetokake kanggo Discovery (Aku nimbali wong-wong bab riko dentist) ngasilaken ing callback dening salah siji agen Discovery kang. Banjur padha takon kula kanggo njlèntrèhaké masalah, rinci lan nulis, kanggo nerangake luwih saka perspektif apa wis nemen kedaden. Aku kapekso. Pranyata metu aku hak bab wong-wong mau ora kang “seneng banget” bab iku. Ing kasunyatan padha tenan ora kaya iku. About three weeks later, Planet Fitness dibalekake kula ing FULL kanggo kabeh monies sing wis tau wis mbayar kanggo wong-wong mau.

Discovery Awesome. 🙂

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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”. 🙂

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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 (tenan, 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, mesthi, 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. 🙂

Part 2 coming soon

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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 lan Gmail users. In my case it was Pidgin having an issue with the Jabber layanan (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.

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