lindner's Known

Also I'm doing connected sites work (try connecting your yahoo/live account!) there's a lot of cool stuff we can do together. Just let me know at plindner@google.com

#paullindner #paullindner

lindner

September 27, 2010

Making the Internet Better - Google Edition

2 min read

I've been very fortunate in my career. I've had many opportunities and been successful in making the Internet a better place for end-users and developers. From the early days of Gopher to the mainstreaming of open-source at Red Hat to the rise of blogging at Six Apart and on to forming the social web with Opensocial -- I've been a part of many game-changing technologies first hand. It's one of the most satisfying parts of my work.

That's why I'm happy to announce that I'm joining Google today. My gut tells me that this is the right company, the right team, and the right time to contribute to and help define another major change that betters the internet and the entire world.

The decision to work for Google did not come easy. My time at LinkedIn has been truly amazing. The people are smart, the technology is stellar and the opportunities to learn and contribute are limitless. In the past year and half the company doubled in size while the Platform team launched dozens of great new products and enhancements. I'm especially proud of the small parts that I played in helping launch LinkedIn's open developer program and am equally excited about a number of future projects that will launch in the near future. I cherish the friendships and knowledge gained and will miss everyone there greatly.

I look forward to the exciting things that I'll be able to accomplish soon. Here's to the next evolution and revolution!

lindner

September 4, 2010

paul.vox.com lives here now...

1 min read

I just completed exporting my Vox to Typepad. Quite a trip down memory lane; back to the golden age of blogging. I'm thinking kind thoughts for Six Apart right now -- I know this can't be an easy transition they're going through.

lindner

November 22, 2009

Fedora 12, Dracut, dmraid, mdadm, oh my!

3 min read

It appears that Fedora 12 moved to a new boot init system called dracut. Sadly due to a number of odd circumstances this has caused me much pain. Here's my basic config

/boot and / on /dev/sda
/var and /home on a partitioned software raid on /dev/sd{cd}

After an yum-based upgrade to Fedora 12 I rebooted. We get to the point where we initialize the software raid and boom. failure. I'd seen this before, partitioned raid has always had some trouble in fedora. Previously I had to modify the rc.sysinit script to reset the raid partitions, so I tried that again, moving that init to later in the boot sequence. Reboot and yes, it works..

However then I noticed some odd things. I was only getting a single drive in my mirrored RAID. Further investigation revealed that I had a device dm-1 instead of sdc or sdd listed in /proc/mdstat... Uh oh..

Looking more closely it appears that my drives were getting set up by dmraid as a fake-raid mirror:

# dmraid -r
/dev/sdd: sil, "sil_aiabafajfgba", mirror, ok, 488395120 sectors, data@ 0
/dev/sdc: sil, "sil_aiabafajfgba", mirror, ok, 488395120 sectors, data@ 0

I tried adding the nodmraid option to grub.conf but then the new dracut system started an infinite spew of messages generated by this mdadm error message string (lifted from Assemble.c)

fprintf(stderr, Name ": WARNING %s and %s appear"
" to have very similar superblocks.\n"
" If they are really different, "
"please --zero the superblock on one\n"
" If they are the same or overlap,"
" please remove one from %s.\n",
devices[best[i]].devname, devname,
inargv ? "the list" :
"the\n DEVICE list in mdadm.conf"

Drats! the mirrored fake raid had already mangled my second drive by duplicating the superblock! Plus since all this was going on in dracut I couldn't fix it. So I removed the nodmraid option in grub during boot and dug a little deeper. I found that I could keep dracut from doing all this nonsense by adding the following kernel options:

rd_NO_MD rd_NO_DM nodmraid

This allows for a minimal boot without dmraid or mdadm. After that I was dropped into single user mode with the dupe superblock message. To fix this required zeroing the superblock of sdd

mdadm --zero-superblock /dev/sdd1

And then rebooting (again!)

Once past this things started working somewhat normally. To get my raid mirrored again I did the normal thing:

# mdadm --manage /dev/md_d0 --add /dev/sdd1

To get rid of the false-positive fake raid setup I found that you can do this with the dmraid tool itself:

[root@mirth ~]# dmraid -E -r /dev/sdd

Do you really want to erase "sil" ondisk metadata on /dev/sdd ? [y/n] :y

[root@mirth ~]# dmraid -E -r /dev/sdc

Do you really want to erase "sil" ondisk metadata on /dev/sdc ? [y/n] :y

The really odd thing about this whole incident is that I never had these drives in a fake raid setup before.

In any case, hope this helps the few other people who might have this same problem.

#dmraid #linux #mdadm #raid