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Re: cache, Xen, and zfsonlinux
by Russell Coker 17 Oct '12

17 Oct '12

On Mon, 15 Oct 2012, Daniel Pittman <daniel(a)rimspace.net> wrote: > > For the mail spool a zvol would be a bad idea, fsck on a 400G Ext3/4 > > filesystem is a bad thing and having the double filesystem overhead of > > Ext3/4 on top of a zvol is going to suck for the most disk intensive > > filesystem. > > zvol is more like an LVM logical volume than a filesystem, so the > overhead isn't nearly as much as this comment suggests. That said, > running ext3 (especially) or ext4 on top of it is going to be slower, > and means you can't use the RAID style features of ZFS, and you give > up object level checksums. I had the impression that a zvol gets all the consistency benefits of ZFS but for a block device. ZFS on top of a zvol may not be a good idea as ZFS is fairly heavy, BTRFS on top of a zvol might be an option though. > > Any suggestions? > > I would aim to run ZFS in the mail domU, and treat the zvol as a > "logical volume" block device. You will have some overhead from the > double checksums, but robust performance. It treats the underlying > dom0 ZFS as a fancy LVM, essentially. You probably also need to > allocate substantially more memory to the domU than you would > otherwise. Yes, lots more RAM in both Dom0 and DomU. The problem is that I have servers with 16G of RAM that I'd prefer not to upgrade. > My fallback would be NFS shared ZFS in the domU - much cheaper because > you only have one ARC, set of checksums, etc, to manage, but with the > added bonus of NFS between the domU and dom0. Fun times. > > Are you sure that LXC or OpenVZ wouldn't better fit your needs than > Xen? You trade off marginally less isolation between containers for > the simplicity of having a single kernel image - so native ZFS > performance. That's a possibility. What is the support for them like in Debian/Wheezy? On Mon, 15 Oct 2012, Jason White <jason(a)jasonjgw.net> wrote: > XFS doesn't have the fsck problem, but it isn't optimized for large numbers > of small files, as I recall. I can't comment on reliability/performance. I > don't know much about JFS either - XFS seems to be receiving more > development attention from Red Hat and elsewhere at the moment. I don't > think Reiser 3 is seeing much work anymore either. XFS has had FSCK problems in the past. I think that JFS is as good as dead. Even before Hans was arrested there were some issues with ReiserFS such as the fact that hostile data written to a file by a user could cause a corruption at FSCK time. If you use ReiserFS for any server that allows binary data to be stored by a user then you risk security problems. -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/

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Gentoo Linux on a Macbook Pro.
by brettawiggins＠tpg.com.au 16 Oct '12

16 Oct '12

Hi Everyone, I'm new to the list and this is my first post. I've been given a Macbook 4,1 (2008) from a friend and I would like to install Linux on it. I have never installed Linux on a Macbook before so I'm in unfamiliar waters. I know that it has no bios and I think uses something called EFI for booting. I want to install Gentoo Linux on the Macbook. I'm using the SystemRecueCD usb installer because it's gentoo based and the DVD drive on this Macbook is shot. The main gaps in my knowledge with doing this install surround Grub and partitioning. Is installing and configuring grub different? Do I have to change the way I setup partitions? I don't want to dual boot, I just want a pure Gentoo MacBook. Has anyone on the list done a Macbook before? As I said I've never done this type of install before and know nothing about Macbooks or EFI. thanks, Brett.

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ocfs2 vs gfs
by James Harper 15 Oct '12

15 Oct '12

I am presently using ocfs2 managed by a pacemaker cluster on Debian Wheezy, and while it works great while everything is up, rebooting a node has mixed results, things really start to go south as on reboot another node will get upset and crash which has a bit of a cascade effect sometimes requiring manual intervention to resolve. Can anyone comment on their experience with gfs and/or ocfs2 and reliability? I'm using ocfs2 to store xen configs, and iso images for xen vm's, so performance really isn't a consideration while reliability is. Thanks James

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Problems getting stack traces from Python program under Kubuntu 12.10
by Chris Samuel 15 Oct '12

15 Oct '12

Hi folks, I'm trying to get to the bottom of this bug: https://bugs.launchpad.net/ubuntu/+source/synaptiks/+bug/1039261 The tl;dr version is that the Python interpreter is somehow emitting two calls to the Xorg libXi function XIQueryVersion(), the first call sends a client XInput version number of 2.1 and then the second one sends 2.0 (seen using xtrace). The second call causes a BadValue error, because you're not meant to send a lower value on any later calls. This causes the comical error: # The version of the XInput extension installed on your system is # too old. Version 2.0 was found, but at least version 2.0 is required The problem is that the Python code only has the second call sending the 2.0 version number, there is no other call in the package that will send anything else, let alone the 2.1 value. So I want to generate a call trace every time the XIQueryVersion() function is called, but I'm struggling to get it to work. The killer at the moment is that both ltrace and gdb (when told to trace children) hang when python runs dash to run ldconfig which calls ldconfig.real and that blocks - so I never get to the point where the function gets called the first time. Any ideas? cheers, Chris -- Chris Samuel : http://www.csamuel.org/ : Melbourne, VIC

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Sound troubles on Toshiba laptop
by Robert Parker 15 Oct '12

15 Oct '12

A friend of mine has a Toshiba laptop which has been running Ubuntu 10.04 successfully. We have just installed Ubuntu 12.04 on it, 32 bit version, and we cannot get sound functioning. The machine is a Toshiba M115-S1064. Have already tried alsamixer with no luck. Where to from here? Bob Parker

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Modern OpenWRT / ddwrt compatible router?
by Paul Dwerryhouse 14 Oct '12

14 Oct '12

Does anyone have recommendations for a modern wifi-router that is compatible with OpenWRT or ddwrt? I've had it with one particular WRT54-GL that I've been maintaining. There's a bug in the b43 driver which causes the wifi to die whenever there's high load, and the suggested workaround[1] doesn't seem to work. Furthermore, the next release of OpenWRT isn't going to work on devices with 16Mb of RAM or less, anyway. Basically, I'm after some sort of wifi router with at least four ethernet ports + one uplink port, that is well supported by OpenWRT, doesn't use b43 for its wifi interface, 64Mb RAM, preferably a lot of flash and is readily available in Australia. Cheers, Paul [1] https://dev.openwrt.org/ticket/7552 -- Paul Dwerryhouse | PGP Key ID: 0x6B91B584 http://weblog.leapster.org/

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mod_pagespeed
by Russell Coker 13 Oct '12

13 Oct '12

https://developers.google.com/speed/pagespeed/mod I've just downloaded and installed the Debian AMD64 package of the Google Apache Pagespeed module. https://developers.google.com/speed/pagespeed/insights#url=etbe.coker.com.a… https://developers.google.com/speed/pagespeed/insights#url=etbe.coker.com.a… According to the above URLs the web performance scores for my blog were 93 for non-mobile and 88 for mobile both before and after installing mod_pagespeed. It appears that Pagespeed isn't doing any good according to Google's analysis! etbe.coker.com.au 10.0.151.178 - - [13/Oct/2012:05:22:31 +0000] "GET /wp- content/plugins/openid/f/W.openid.css,qver=519.pagespeed.cf.Bbu1gxRjUE.css HTTP/1.0" 200 2165 "http://etbe.coker.com.au/" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/21.0.1180.89 Safari/537.1" 0 etbe.coker.com.au 10.0.151.178 - - [13/Oct/2012:05:22:31 +0000] "GET /wp- content/themes/atahualpa/js/DD_roundies.js,qver=0.0.2a.pagespeed.jm.4gw5yluag0.js HTTP/1.0" 200 3679 "http://etbe.coker.com.au/" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/21.0.1180.89 Safari/537.1" 0 etbe.coker.com.au 10.0.151.178 - - [13/Oct/2012:05:22:31 +0000] "GET /wp- includes/js/jquery/jquery.js,qver=1.7.2.pagespeed.jm.XZwfunyK-6.js HTTP/1.0" 200 33587 "http://etbe.coker.com.au/" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/21.0.1180.89 Safari/537.1" 0 etbe.coker.com.au 10.0.151.178 - - [13/Oct/2012:05:22:33 +0000] "GET /wp- content/themes/atahualpa/images/xlogo.png.pagespeed.ic.ICWmaHBME5.png HTTP/1.0" 200 2267 "http://etbe.coker.com.au/" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/21.0.1180.89 Safari/537.1" 0 The above sample of web logs shows that the string "pagespeed" is appeneded to some URLs with a hash of the file contents which apparently allows much longer cache times without making it difficult to change content. So Pagespeed is obviously doing something. Is Google analysis expected to say that there is no change? Note that my speed scores are 93% and 88% so my site is was apparently quite good before mod_pagespeed was installed - maybe the analysis would report a difference on a site that didn't perform so well. -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/

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RE: modem hangup (SIGHUP) on connection
by zlinw＠mcmedia.com.au 11 Oct '12

11 Oct '12

No problem now, Works OK, Optus must have been asleep. Just a minor question where was the origin of the SIGHUP, its not real clear from the syslog. Previous similiar occurances in the past the origin of the SIGHUP being the ISP. This appears to be the case here Lindsay

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modem hangup (SIGHUP) on connection
by Lindsay Sprinter 11 Oct '12

11 Oct '12

I have radio broadband via Virgin who uses the Optus network, This morning immediately on connection it hangs up. Below is the syslog entry for an attempt. Any one have any idea on why the (SIGHUP) appears at the end.... The system was rebooted same thing occurs, the old reliable phone line dialup still works though so the basic pppd operation and networking on the system works OK. Will a packet sniffer tell me anything. I am inclined to leave it till tomorrow to debug the issue as I have found this service is not the most reliable on the planet. Oct 11 04:41:22 wolfdualp3 chat[3527]: -- got it Oct 11 04:41:22 wolfdualp3 chat[3527]: send (ATE1^M) Oct 11 04:41:22 wolfdualp3 chat[3527]: timeout set to 60 seconds Oct 11 04:41:22 wolfdualp3 chat[3527]: send (ATD*99#^M) Oct 11 04:41:22 wolfdualp3 chat[3527]: expect (CONNECT) Oct 11 04:41:22 wolfdualp3 chat[3527]: ^M Oct 11 04:41:22 wolfdualp3 chat[3527]: ATE1^M^M Oct 11 04:41:22 wolfdualp3 chat[3527]: OK^M Oct 11 04:41:22 wolfdualp3 chat[3527]: ATD*99#^M^M Oct 11 04:41:22 wolfdualp3 chat[3527]: CONNECT Oct 11 04:41:22 wolfdualp3 chat[3527]: -- got it Oct 11 04:41:22 wolfdualp3 chat[3527]: send () Oct 11 04:41:22 wolfdualp3 pppd[3526]: Serial connection established. Oct 11 04:41:22 wolfdualp3 pppd[3526]: using channel 4 Oct 11 04:41:22 wolfdualp3 pppd[3526]: Using interface ppp0 Oct 11 04:41:22 wolfdualp3 pppd[3526]: Connect: ppp0 <--> /dev/ttyUSB0 Oct 11 04:41:23 wolfdualp3 pppd[3526]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x5b40ae5> <pcomp> <accomp>] Oct 11 04:41:23 wolfdualp3 pppd[3526]: rcvd [LCP ConfReq id=0xf <asyncmap 0x0> <auth chap MD5> <magic 0x125526b> <pcomp> <accomp>] Oct 11 04:41:23 wolfdualp3 pppd[3526]: sent [LCP ConfNak id=0xf <auth chap MS-v2>] Oct 11 04:41:23 wolfdualp3 pppd[3526]: rcvd [LCP ConfAck id=0x1 <asyncmap 0x0> <magic 0x5b40ae5> <pcomp> <accomp>] Oct 11 04:41:23 wolfdualp3 pppd[3526]: rcvd [LCP ConfReq id=0x10 <asyncmap 0x0> <auth pap> <magic 0x125526b> <pcomp> <accomp>] Oct 11 04:41:23 wolfdualp3 pppd[3526]: sent [LCP ConfAck id=0x10 <asyncmap 0x0> <auth pap> <magic 0x125526b> <pcomp> <accomp>] Oct 11 04:41:23 wolfdualp3 pppd[3526]: sent [PAP AuthReq id=0x1 user="irrelevant" password=<hidden>] Oct 11 04:41:23 wolfdualp3 pppd[3526]: rcvd [LCP DiscReq id=0x11 magic=0x125526b] Oct 11 04:41:23 wolfdualp3 pppd[3526]: rcvd [PAP AuthAck id=0x1 ""] Oct 11 04:41:23 wolfdualp3 pppd[3526]: PAP authentication succeeded Oct 11 04:41:23 wolfdualp3 pppd[3526]: sent [IPCP ConfReq id=0x1 <addr 0.0.0.0>] Oct 11 04:41:24 wolfdualp3 pppd[3526]: rcvd [IPCP ConfNak id=0x1 <ms-dns1 10.11.12.13> <ms-dns3 10.11.12.14> <ms-wins 10.11.12.13> <ms-wins 10.11.12.14>] Oct 11 04:41:24 wolfdualp3 pppd[3526]: sent [IPCP ConfReq id=0x2 <addr 0.0.0.0>] Oct 11 04:41:24 wolfdualp3 pppd[3526]: Hangup (SIGHUP) Oct 11 04:41:24 wolfdualp3 pppd[3526]: Modem hangup Oct 11 04:41:24 wolfdualp3 pppd[3526]: Connection terminated. Oct 11 04:41:25 wolfdualp3 pppd[3526]: Exit. Lindsay Linux now for 19 years, how time flies.................

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python-iview
by Russell Coker 11 Oct '12

11 Oct '12

http://theconversation.edu.au/python-iview-copyright-crusader-or-vigilante- operative-9763 I'm sure that many people here are aware of Jeremy Visser’s good work in creating the python-iview program to allow those of us who don't use Flash to access ABC TV content over the Internet. Unfortunately the ABC has threatened legal action against him in regard to this issue and he has taken down the repository of the source code. https://jeremy.visser.name/2012/09/python-iview-press-qanda/ Jeremy has published a FAQ at the above URL. It's interesting that the ABC apparently have a TOS hidden away somewhere that tells us not to download episodes. If the ABC had asked Jeremy to make his program stream programs instead of downloading them they could also have asked him to display the TOS. Anyway I just noticed this because the "iview-cli -p" command has started to fail repeatedly with the following error and I went looking for a newer version of the source. Traceback (most recent call last): File "/usr/bin/iview-cli", line 179, in <module> programme() File "/usr/bin/iview-cli", line 44, in programme items = iview.comm.get_series_items(series['id']) File "/usr/lib/pymodules/python2.7/iview/comm.py", line 93, in get_series_items return parser.parse_series_items(series_json, get_meta) File "/usr/lib/pymodules/python2.7/iview/parser.py", line 105, in parse_series_items for item in series_json[0]['f']: IndexError: list index out of range I wondered if the ABC had changed something to make it fail. I don't imagine that they would deliberately try to make iview-cli crash, but I can imagine them putting in a hack to abort the connection in a way that iview-cli doesn't expect. I've just tried iview-gtk and that works well enough, so maybe it's just a bug in the cli version of the software. -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/

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