July 2013 - luv-main - example.com

Re: Getting started with ZFS
by Petros 17 Jul '13

17 Jul '13

Quoting Tim Connors > I've got one for you; just came in on the mailing list (someone got stale > mounts when their kernel nfs server restarted): >> ZFS and the NFS kernel server are not that tightly integrated. >> >> When you do a 'zfs set sharenfs="foo,bar" pool/vol' of a 'zfs >> share >> pool/vol', the zfs tools just give a call to the NFS kernel server >> saying 'Hey I want you to share this over NFS'. That's what it should do. Under FreeBSD it sends a HUP to mountd - that's it. >> >> If the NFS kernel server is restarted it unshares everything and only >> reads back whatever is in /etc/exports. This is actually expected as >> NFS doesn't know anything about ZFS. Doing a >> 'zfs share -a' exports all your NFS/SMB shares again. Yes, it is a dependency. In general /etc/init.d or /etc/rc.d .. scripts take care of it so there is room for improvement if it is not done yet. >> When you don't use your system native tools, or when someone tries to >> solve something at the wrong layer (zfs trying to mess around with >> NFS? It uses - it just has another list as /etc/exports. It's not a big deal, I would think. ZFS changes the way to work with filesystems in may ways. Who would create/clone/destry/move around filesystems as I do with ZFS now? I have 164 ZFS filesystems on the system I just queried. It makes sense to keep the list of exports here. On a ZFS system, /etc/exports is a "legacy file". BTW: the ZFS hierarchy gives you better control access to parts of the directory than on other filesystems, because it is easy to create a new ZFS for a directory tree and give it different export options. Regards Peter

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Re: Getting started with ZFS
by Toby Corkindale 16 Jul '13

16 Jul '13

On 16/07/13 09:45, Petros wrote: > Quoting "Tim Connors" <tconnors(a)rather.puzzling.org> > >> Don't ever use more than 80% of your file system? Yeah, I know that's not >> a very acceptable alternative. > > The 80% is a bit of an "old time myth", I was running ZFS with higher > usage under FreeBSD until I hit the "slowness". Chipping in with a bit of real-world info for you here. Yes, ZFS on Linux still suffers from massive slowdowns once you run out of most of the free space. It's more than 80%, I'll grant, but not a whole lot - maybe 90%? > BTW: I don't use dedup. Firstly because I use cloning many times and > after that: Well, that are changes unique to the ZFS in question. > > I have problems to come up with a scenario to use it. But I am pretty > sure someone asked for it. Maybe someone running a big big server farm > and distributing copies of many many Gigabytes of data to many VMs on > the same box? Dedup is really painful on zfs. Attempting to use it over a multi-terabyte pool ended in failure; using it just a subset of data worked out OK, but ended up with >50GB of memory in the server to cope. Fine for a big server, but how many of you are running little fileservers at home with that much? You do save on a fair bit of disk space if you're storing a pile of virtual machine images that contain a lot of similarities. -Toby

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claws mail navigation
by Russell Coker 15 Jul '13

15 Jul '13

When reading mail in the default claws configuration if the keyboard focus is in the message list then the up/down/pgup/pgdn arrow keys allow you to move through the list. Then you press ENTER to view the message that the cursor is on. You can press SHIFT-TAB twice to take keyboard focus to the message that is being read and then use up/down/pgup/pgdn to scroll within the message. I want to have it display the way Kmail does. In kmail you use the left/right arrow keys to scroll in the list of messages and the message is displayed immediately that it is selected (no selecting a message and pressing ENTER to see it). The use of left/right arrows means that up/down/pgup/pgdn can be used for reading the message. This means that the routing aspects of reading mail in kmail can be conveniently done without using the mouse (SHIFT-TAB is not convenient) and with maximum speed. One key press to do every common operation should be the aim. In Kmail I press the right arrow key to display a message. In Claws I press the down arrow key to go to the list entry and then ENTER to view the message, but that's only if I have the keyboard focus in the message list. So in Kmail if I want to skim many messages that are more than one screen long (EG the BTRFS mailing list which tends towards long messages of minor interest to me) then I do the following to read a message: 1) RIGHT 2) PGDN, PDGN 3) DEL In Claws with the default config it would be: 1) Click mouse on message in listbox 2) Click mouse in body of message and scroll down - or hover over and use scroll-wheel when using a desktop system (scrolling isn't an option for my Thinkpad 3) DEL Kmail is much better for this. When you have 3000 unread mailing list messages the ability to skim and delete a typical message in less than a second with Kmail really matters. Before anyone asks, no I don't want to go to a text-mode MUA. I want a GUI MUA that has keyboard shortcuts that allow fast and efficient operation. For scanning mailing list mail the K9 MUA on an Android phone is possibly going to give me a better average speed than Claws on a 27" monitor. This is a sign of a serious design problem with Claws. Now IMAP allows an unlimited number of email clients to share a mailbox. Modern storage is large enough that having multiple copies of the email on one system isn't a problem. So I guess I could use one IMAP client to triage mail and then another to compose mail, manage the offline archive of old mail (that's not in IMAP) and do the other advanced tasks. But it would be nice if one MUA could do it all. -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/

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Configuring network packet queuing
by Jason White 12 Jul '13

12 Jul '13

I've been reading this article: https://gettys.wordpress.com/2013/07/10/low-latency-requires-smart-queuing-… LWN article with comments: http://lwn.net/Articles/558603/ This is very much outside any area in which I have experience. How do I set up fq.codel under Debian? My machine has an ADSL card, hence there is no router or modem (with its own queue) between my system and the DSL link, so it seems plausible to conclude that I might benefit in some circumstances from setting this up. What's the configuration procedure under Debian? The kernel module is included in the Debian 3.9 kernel.

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eMMC/SD fs tuning
by trentbuck＠gmail.com 11 Jul '13

11 Jul '13

I just read [0] and have some notes and questions to share. [0] http://elinux.org/images/b/b6/EMMC-SSD_File_System_Tuning_Methodology_v1.0.… Questions: - the FTL is opaque to the user and the OS. Where can I find a mapping of make/models to FTLs? For SSDs that would be the make/model of the SSD, but for SD I believe the FTL is implemented in the reader, not in the SD card. Where can I find honest (i.e. independent) analysis of FTL metrics? - Max claims bonnie++'s functionality is superseded by fio. Russell, you maintain bonnie++, right? What's your opinion of fio? Notes: - p 9 flashbench helps you guess the erase block size. - pp 10-12 lists fs and scheduler optimization knobs. - p 13 btrfs likes -o ssd if device speaks TRIM. ext4 likes noatime/nojournal, CFQ and discard. CFQ is best for most things, then ROW. - p 23 optimal configuration differs between device make/model. optimzation helps r/w loads more than r/o or w/o loads. - p 26 avoid btrfs/f2fs if OS can be reset by unscheduled power outage or hardware watchdog, unless you have a BBU or similar. ext4 survives many more outages than btrfs/f2fs.

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Libre Office on Kubuntu 13.04
by Bob 11 Jul '13

11 Jul '13

Hi all, I am using Libre Office wordprocessor on Kubuntu 13.04. My data is stored on a NAS (Synology DS213+) and accesses using NFS. When trying to access files from the NAS, LibreOffice locks up and freezes. There are no problems with any other programs accessing data (including Email etc) . Copying a file to the local computer allows it to be opened OK by LibreOffice, so it appears to be a problem with LibreOffice and networking. I upgraded Kubuntu from 12.10 to 13.04 and upgraded the NAS (from a DS209) at about the same time so can't be certain which one is causing the problem. However, as all other programs are accessing OK I would suspect it is LibreOffice. Has anyone else experienced this? Anywhere I should look? Thanks Bob

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managing Wifi services
by Russell Coker 11 Jul '13

11 Jul '13

Is there a good Debian package for managing Wifi access? Adding an entry to /etc/network/interfaces is OK if you only have one ESSID. But if you are going to connect to one of several phones, a home Wifi, McDonalds, and others then it becomes tiring to edit that file. I'd like something that allows a laptop to do the same things as an Android phone. To just automatically connect to a Wifi network that's in range. Ideally it would do it whenever there's no link on the Ethernet port. -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/

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Re: [luv-talk] Facebook.. Privacy? What privacy?
by Russell Coker 10 Jul '13

10 Jul '13

Firstly, this discussion is specifically about typical Linux installations and programs which are mostly run on Linux. While I expect that similar issues can be found with *BSD it's still obviously related to the Unix family of OSs. Also it should be noted that LUV has never at any time been opposed to discussion of other free Unix OSs, at the very first meeting when names were being discussed it was generally agreed that FreeBSD was on-topic for all LUV events. This discussion belongs on luv-main. On Wed, 10 Jul 2013, "Trent W. Buck" <trentbuck(a)gmail.com> wrote: > Brian May wrote: > > Programs shouldn't even be recording all of the stuff in > > ~/.xsession-errors > > As Russell pointed out, that's just where X's stderr (and stdout, I think) > goes. I didn't directly say that, but I think I implied it clearly. For people with our experience there isn't really a difference, but for some people the fact that you can run an application and see it's output doesn't necessarily imply stdout/stderr. > > Just noticed mine is filling up fast with the following error. I think I > > might have to investigate this. Not really sure what is running amixer > > though (I use awesome, so no, not gome/kde stuff) > > I filled /home a couple of times due to .xsession-errors. I've done that too. This is really a serious problem, particularly when you have so many ways that running out of disk space can cause data loss. For example most of the history of Kmail has had it lose mail from POP servers if you run out of disk space. Also the earlier versions of BTRFS would behave badly in ways you really won't like if all disk space was used up. > I found on Debian, chmod -w'ing it causes it to fill /tmp instead (and > for me that's a tmpfs and I reboot regularly, so it neatly sidesteps > the issue). Losing data from /tmp shouldn't be such a problem in theory at least. In practice I'm sure that there are more than a few programs which write truncated data to other filesystems if /tmp if full. :( -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/

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system debugging - was Re: [luv-talk] Facebook.. Privacy? What privacy?
by Russell Coker 10 Jul '13

10 Jul '13

On Wed, 10 Jul 2013, "Trent W. Buck" <trentbuck(a)gmail.com> wrote: > Jason White wrote: > > read ~/.xsession-errors and consider all of the messages from > > components one didn't even know existed. One is then faced with the > > practical question: against which package to submit a bug report. > > Um, you make an educated guess, and if you filed it against the wrong > package, it's the Debian maintainer's responsibility to reassign it. A large portion of those error messages (probably the vast majority on most systems) will be from applications such as kmail and chromium which can be run from a terminal. To solve the problem of excess error messages you could run all such programs separately to identify their logs and then after those are identified (and hopefully fixed) the rest would be known to be due to the desktop environment. The messages which are known to be due to the desktop environment can have bugs reported against a meta-package for KDE, GNOME, or whatever desktop environment is in use and whoever maintains that will be well qualified to triage them. It's not the DD's responsibility to determine the source of a random error message. -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/

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FW: Delivery Failure Notification
by James Harper 09 Jul '13

09 Jul '13

If I'm reading this right, there is an m.delves(a)ballarat.edu.au subscribed to this list, and that email address no longer exists. James > -----Original Message----- > From: Mail Delivery System [mailto:postmaster@ballarat.edu.au] > Sent: Sunday, 7 July 2013 12:48 PM > To: James Harper > Subject: Delivery Failure Notification > > With reference to your message addressed to: > m.delves(a)ballarat.edu.au > > One or more addresses in your message have failed with the following > responses from the mail transport system: > > User <m.delves(a)ballarat.edu.au> is not known at this site > > Should you need assistance, please mail postmaster(a)ballarat.edu.au > > ------------------- Returned header follows ---------------------- > > Received: from antispam2.ballarat.edu.au ([141.132.64.22]) > by gretel.ballarat.edu.au (1.05.63) with SMTP id 500166000; > Sun, 7 Jul 2013 12:46:50 +1000 > Received: from tainted.luv.asn.au ([202.158.218.239]) > by antispam2.ballarat.edu.au with ESMTP; 07 Jul 2013 12:46:36 +1000 > Received: from tainted (localhost [127.0.0.1]) > by tainted.luv.asn.au (Postfix) with ESMTP id F33E02510F; > Sun, 7 Jul 2013 12:46:35 +1000 (EST) > X-Virus-Scanned: Debian amavisd-new at lists2.luv.asn.au > Received: from tainted.luv.asn.au ([127.0.0.1]) > by tainted (lists.luv.asn.au [127.0.0.1]) (amavisd-new, port 10024) > with ESMTP id ei3oIcWQMJF8; Sun, 7 Jul 2013 12:46:33 +1000 (EST) > Received: from tainted.luv.asn.au (localhost [127.0.0.1]) > by tainted.luv.asn.au (Postfix) with ESMTP id 3AFCD25137; > Sun, 7 Jul 2013 12:46:21 +1000 (EST) > X-Original-To: luv-main(a)luv.asn.au > Delivered-To: luv-main(a)luv.asn.au > Received: from tainted (localhost [127.0.0.1]) > by tainted.luv.asn.au (Postfix) with ESMTP id 1CA9225109 > for <luv-main(a)luv.asn.au>; Sun, 7 Jul 2013 12:46:17 +1000 (EST) > X-Virus-Scanned: Debian amavisd-new at lists2.luv.asn.au > Received: from tainted.luv.asn.au ([127.0.0.1]) > by tainted (lists.luv.asn.au [127.0.0.1]) (amavisd-new, port 10024) > with ESMTP id d-yS3ugRlF4l for <luv-main(a)luv.asn.au>; > Sun, 7 Jul 2013 12:46:11 +1000 (EST) > Received: from smtp2.bendigoit.com.au (mail.bendigoit.com.au > [203.16.207.99]) > by tainted.luv.asn.au (Postfix) with ESMTPS id 4046A25106 > for <luv-main(a)luv.asn.au>; Sun, 7 Jul 2013 12:46:11 +1000 (EST)

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