A Quick Dracut Module

Since the general trend on many linux distros is towards requiring /usr to be mounted at boot time, I figured I’d see what it would take to get it working using dracut.

I’ve been messing with dracut for a while, and for some reason it stubbornly refuses to detect my raid devices. The kernel autodetection works fine, but this is disabled when booting from an initramfs. Dracut would timeout and drop me to a dash shell, and if I just typed mdadm -As followed by exit it would boot just fine.

Dracut is using udev to set up raid devices, and obviously that is not working.

Beyond this, I’d like to get my /usr mounted pre-boot, and there is a module called usrmount that purports to do just this. However, it isn’t working in my case because /usr is a bind mount to a subdir on an lvm volume, and it just isn’t figuring that out (it doesn’t even run lvm in the first place despite having the module installed, let alone figuring out what to mount in what order – I suspect the lvm module only works if root is on lvm).

My solution to both problems is to build my own simple dracut module. If you want to try it out:

1. cd /usr/lib/dracut/modules.d/
2. mkdir 91local
3. cat > 91local/module-setup.sh
   #!/bin/bash
   # -*- mode: shell-script; indent-tabs-mode: nil; sh-basic-offset: 4; -*-
   # ex: ts=8 sw=4 sts=4 et filetype=sh

   check() {
   return 0
   }

   depends() {
   return 0
   }

   install() {
inst_hook pre-trigger 91 "$moddir/mount-local.sh"
}


4. cat > 91local/mount-local.sh
   #!/bin/sh
   # -*- mode: shell-script; indent-tabs-mode: nil; sh-basic-offset: 4; -*-
   # ex: ts=8 sw=4 sts=4 et filetype=sh

   mount_local()
   {
   mdadm -As
   lvm pvscan
   lvm vgscan
   lvm lvscan
   lvm vgchange -ay
   }

   mount_local

Then run dracut to build your initramfs, and it should let mdadm and lvm auto-detect everything before it gets to mounting stuff. You can then use the fstab-sys to mount whatever you need to mount user. However, in your fstab.sys if you’re configuring a bindmount be sure to prepend /sysroot/ before the source directory.
Example fstab.sys:
/dev/vg1/data /data ext4 noatime,user_xattr,barrier=1 0 0
/sysroot/data/usr /usr none bind 0 0
/sysroot/data/var /var none bind 0 0

Hopefully this helps somebody out – the dracut documentation is pretty sparse. In fact, if somebody connected to dracut stumbles upon this I’d be open to a better way of hooking my script – pre-trigger just doesn’t seem right – I’d rather let udev try to do everything first. However, I couldn’t find any way to hook after udev runs but before it bombs out not finding my root device. Suggestions welcome.

Another MythTV Update

Agreeing with some advice on gentoo-dev, I’m going to post this as a blog entry instead of a Gentoo news item. The quick version of this update is expect to see 0.24.1 in portage in a few days. The long version follows…

KDump on Gentoo

I’ve been trying to learn a little more about kernel debugging (part of my quest to learn a little more about btrfs), and I figured I’d post a quick howto on getting kernel crash dumps captured on Gentoo.

The Foundation Activity Tracker

If you haven’t noticed on gentoo-nfp, I’ve created an activity tracking page (with the help of David Abbot) to track periodic compliance activities for the Foundation.

Some have asked why do this, and why not simply use the Gentoo Calendar/etc to accomplish this?

What’s Up With MythTV on Gentoo?

I’ve gotten a few fair questions over the last few weeks about the status of MythTV on Gentoo. Here is a quick synopsis of where things stand…

Gaps in the Cloud

Well, I’ve been getting a lot of use out of my CR-48 ChromeOS netbook, and I’ve found that I can do almost everything I normally do with it, although not always with FOSS. There are a few gaps that I haven’t found either proprietary or FOSS options for, and that is the focus of this post.

The biggest one is financial management. I’ve been stuck away from home for about a week and my CR-48 is my main lifeline to the outside world. I can look up my bills online, and pay my bills online. The one thing I can’t do from my CR-48 is access my checkbook register.

The problem is that I’m using Quicken for my checkbook, and the only way to get at that remotely is to remote desktop into a windows server over ssh (perhaps a virtual one). The CR-48 doesn’t support either RDP or ssh connection forwarding (which is the only way I’d ever use RDP – without setting up a VPN or something equivalent).

The most obvious proprietary alternative online is mint.com, but it really isn’t a Quicken alternative. Mint is great for telling me what happened last week, but horrible for telling me what will happen three weeks from now. I get paid monthly, so I can’t afford to pay somebody $500 today only to find out that I have some big transaction coming in three weeks from now that will send me into the red. Sure, I could just keep some huge balance in my account, but I’d rather keep large balances someplace more useful (like paying down loans or in some kind of decent investment).

Email is a big FOSS gap. Right now I’m using Gmail and that is great. However, it would be better if I could set up my own cloud hosting for Chrome OS authentication/syncing, and have a Gmail-like experience with FOSS. The closest I’ve seen is RoundCube, which is nice, but it lacks the keyboard shortcuts and streamlined interface of Gmail. Drag-and-drop is a real pain on a netbook, and just being able to hit “e” or archive to deal with incoming mail is a lot easier than the multiple-click-on-small-icons workflow of RoundCube to do the same.

FOSS up till now has tended to focus on big desktop applications. I guess it makes sense from the standpoint that the average desktop user isn’t going to set up their own LAMP box. However, I’m perfectly happy to set up a LAMP box and run my own cloud-based services. It just seems like there aren’t many worth running.

I suspect we’ll start to see better solutions if cloud-based netbooks (running ChromeOS or whatever) take off. As we move towards a more mobile world, it becomes more important for data to be accessible on the run.

Oh, and if nothing else it would be REALLY nice if somebody came up with an NX client that runs as a Chrome application. I’ve seen a VNC app, and I guess I could sort-of live with that (if it supports ssh), but NX would be much nicer. An RDP-over-ssh app would also be nice…

First Experiences with the Chrome OS Netbook

Just got a nice surprise in the mail on Thurs – a CR-48 Google Chrome Netbook! Here are some of my first impressions from it.

I have given Chrome OS a test drive or two over the last year, either in virtual machines or using USB drive packages of it. My impression at that time was that this had some potential, but my experience was fairly marred by the low performance of USB flash or virtual machines, and of course the touted benefits like battery life and fast boot don’t really work out well in that kind of environment.

With the Netbook, those particular features stand out – and they do make a big difference. Granted, perhaps my experience with laptops in general has been marred by my employer’s tendency to load their standard image up with junk, but I’ve never found laptops to be “instant-on” in real life, and they struggle with battery life. With Chrome OS I tend to just let it sleep most of the time and I get real instant-on, and if I do power it down the 10 second boot time is VERY realistic – perhaps even pessimistic. Login time – oh, about two seconds. I haven’t tested the full battery life though others have – in my heavy use in the last few days I haven’t gotten the thing under about 85%.

Since I use Chrome as my day-to-day browser I basically was up and running about two minutes after turning the thing on. This is touted as another benefit of Chrome – any device is basically interchangeable with all the cloud syncing. I could see this being useful for an employer – just have a pool of laptops and let employees grab one and use it, rather than having a 1:1 assignment. Provisioning new units of course would be a snap as well.

Performance of the unit is fine – a few webpages that run slowly in Chrome on my desktops run slow on the netbook, but really I see nothing to complain about here.

So, let’s talk about the downsides to the hardware. I’ve always struggled with trackpads. This one doesn’t have hardware buttons, it is purely gestures, and it has two levels of sensitivity (though I’d appreciate if the hard-press required SLIGHTLY less force). I’ve disabled tap-to-click, as perhaps I’m ham-handed, but I find that I constantly bump it and mess up whatever I am typing. Perhaps some intelligence would help here – ramp down the sensitivity when I’ve just typed 500 consecutive characters with no mouse use (hmm, maybe this is a good use for that send-feedback button). Without a hardware button to hold, click-and-drag is difficult except for very short drags, and that complicates things. Also, I’ve found the right-click and middle-click gestures to be unreliable, sometimes causing navigation I don’t want to happen which of course tends to slow me down and possibly lose work.

Click-and-drag is a problem for me, because of the way I manage email. I am a big Thunderbird user, and I used to use SquirrelMail for those times I needed remote access via the web. I just switched to Roundcube which is a little nicer if you have to live with nothing but web, but that app is short on keyboard shortcuts (sounds like another feature request coming on – n for next would be nice, and a delete shortcut as this thing has no DELETE key). I have been browse over search kind of guy with emails for years, and I’m finding that sorting mail into folders with this netbook is pretty painful. I suspect that I’ll need to change over to more of a search mentality to cut down on my need to browse. Gmail really is a better model for limited UI experiences, and I’m wondering if much of that time I spend micro-managing my email is a value-add.

I’m still on the fence about drinking the cool-aid and switching to Gmail entirely, at least as my primary mail interface (perhaps with an archive being sent to my server for safety). Right now I’m hosting my own email, and I really like not having to deal with quotas/etc, and the security of not having it all out on the cloud. I guess if I want to be really trusting I may be able to just have Gmail be an IMAP client to my server. It would be really nice if I could figure out a way to easily just have an IMAP-only password for my account – I’m sure with a little hacking I could get that working, and my email is backed up daily so not too much could go wrong there.

Right now the number of apps that work offline is fairly limited – mainly just notepads/etc. For the most part I’m using my Cr-48 around the house, which doesn’t make that a big problem. In fact, it is pretty rare for me to be completely without network, and my android phone really covers those kinds of remote situations well already. The Cr-48 does have 3G with Verizon, with 100MB free per month for two years. I’m not sure how much I’d even need to use that, but this really would be all I need for the rare email check on the road.

App selection for Chrome is still pretty limited. I’d really like to see:

• Offline Email Client
• NX Client
• SSH Client (better than the crosh one which works in a pinch)
• Offline Google Docs (ok, now I’m dreaming)
• Decent Media Player and File Browsers for external storage

One thing I have found is that you really need to use it for a day or two before passing judgment. Some of the things that drove me craziest passed as I got used to doing things differently. However, I’m still not sure I’m ready to do away with home/end/pgup/pgdown/delete (I never use insert).

I’m sure there will be more to follow. I’d be interested in the impressions of others as well.

Gentoo and Security Updates

While it pains me a bit to say this, and I don’t have a great deal of time to type this, I wanted to at least try to get some kind of word out to our user community that the high-profile kernel regression announced a few weeks ago (and fixed a few weeks ago in almost every other distro), remains a vulnerability in Gentoo with no clear timeline for resolution.

Gentoo bug 337654 is tracking this issue.

Users can emerge a more recent version of gentoo-sources to get the patch, and I’d recommend doing so if local root exploits are something that concern you.

I’d like to dwell a bit longer on solutions, but I don’t really have time to do so right now. Clearly the kernel team could use help with security issues. The security team probably could use help as well in staying on top of these kinds of issues. I don’t want to kick people when they are down – Gentoo is an all-volunteer effort. However, situations like this really don’t do much to improve the reputation of the distro, and at the very least we need to inform users when problems like this arise.

An Appeal to Devs – Please Use News

Well, I spent half of today rebuilding my system, and upgrading mysql.

I figured that I might use the opportunity of my newly-found spare time while running revdep-rebuild to perhaps put out a general plea for developers to make use of the news feature in portage.

Upgrading to mysql 5.1 requires doing a full dump of your databases, some manual cleanup, an upgrade, and then some manual restore steps. Oh, and that dump has to be done BEFORE the upgrade or you end up having to revert back to 5.0 (which I ended up doing). Usually mysql upgrades are relatively painless, but jumps between major versions (0.1 level) are often not.

The upgrade also breaks anything that links to libmysql, which is quite a bit on a system that runs any number of services (mail, mythtv, ulog, etc).

It might have been nice if a news item were published a day or two before stabilizing mysql 5.1 so that users might have some advance warning and could plan accordingly.

Now, this upgrade didn’t rise to the level of some of the past breakages that actually were very painful to recover from and could result in unbootable systems/etc. Still, it never hurts to give users notice. The beauty of news items is that they only pester users who will actually be impacted by them. I don’t think anybody running mysql would mind a reminder that an upcoming upgrade requires careful planning – this is far more relevant to users than half the stuff we put in elogs/etc.

On the other hand, I do appreciate the mysql upgrade guide on the gentoo website (might not hurt to update it a tiny bit), and Peter Davies’s blog entry from 1.5 years ago was very helpful. If these had been pointed out before stabilizing the build the stable experience would have been a little smoother.

Control Over Application Distribution

I was giving some thought to something that flameeyes wrote regarding quality control and application distribution, and rather than a condensed comment I thought I’d elaborate a little on my thoughts.

Before reading on, I’d encourage you to read what he wrote, as I think he gets a lot of things right.

However, where I’d like to add something is where we get into providing a complete platform vs providing a particular user experience built on a platform. What is the difference? Well, let’s take android as an easy example.

Android is a platform, which is open source, although developed arguably in a less than open manner. The Google branded phones are a particular user experience built on the Android platform. There is a certain tendency for users to confuse the two, which is what leads to shouts of “foul” when Google does something to their Market.

The Google Market is not part of Android, so in a sense their control over the Market is part of improving the user experience, and doesn’t reflect a lack of openness on the platform.

The problem with this is that if you look at the platform as ONLY being Android, then the platform turns out to be fairly lacking. Android actually has no package distribution and management system at all. That means that absent the Market all you have is some odd 3rd party clones of the market or the ability to do a one-time install of apks from a website/etc, none of which are really filling the need for a package manager.

How do other platforms handle this? Well, let’s look at Ubuntu, which delivers both a platform, and a default user experience built upon it. In their case, the user experience is really nothing more than a particular default configuration of the platform. In Ubuntu (and most popular linux distros, certainly including Gentoo) the package manager is part of the platform – not the experience. The package manager is open source, and while Ubuntu controls access to their repository, they do not control the package manager. If users want to use another repository (or create their own) they need only add a URL to their package manager, and the new repository gets seamlessly merged into the package database – perhaps with even greater priority than Ubuntu’s official repository if so configured.

If Google’s market operated in the same manner, then it would be part of the platform, and the experience is the quality assurance they provide to it. I think we’d see fewer complaints in this case. The problem is that Google does not allow users to configure their market to include apps published from alternate sources, which means that since Android doesn’t provide a package manager that users effectively have no way to address this capability gap.

Then if you look at the fact that many phone distributors disable parts of the platform, such as the ability to install apps via sources other than the market, you compound the issue.

I see the situation with mozilla in the same way. As long as a mozilla product user can install an extension from any number of sources and receive automatic updates of this extension, then I have no issue with mozzila providing a default experience that has a level of QA. If, on the other hand, mozilla designs their products so that you can only install extensions from their site, or only extensions from their site receive automatic updates/etc, then they’re essentially limiting their platform to intentionally constrain users to have a particular experience.

This is a debate that has also raged on the Gentoo mailing lists. Different people have different attitudes towards QA, and as a result we have a plethora of overlays in Gentoo that provide levels of QA that are different from the official policy. This has the downside of fragmenting development work, and the upside of taking advantage of the flexibility of the platform.

What do you think? What is the best way to provide the best of both worlds? How can a platform provide a “just right” level of QA filtering appropriate for every end user?