Following the same theme as my last post, instead of claiming space added to the end of a volume by extending an existing partition (technically, a "slice" in OpenBSD), I will show how to add a new partition using this space.

I find it convenient to create the new slice as the "d" slice and then put /home onto it.

So, let’s get started.

• Boot into the system’s rescue disk:

  > boot bsd.rd
  

  Then select (S)hell at the prompt.

• Claim extra space

  Re-initialize the MBR, using the entire disk.

  # fdisk -i wd0
  Do you wish to write new MBR and partition table? [n] y
  Writing MBR at offset 0.
  #
  

• Add a new slice for /home (the "d" slice)

  This system has only the root slice and swap. We will add a new slice, using all the unused space at the end. In the following example, I have a 120GB volume, where 20GB is used by root and swap, and the rest unallocated.

  # disklabel -E wd0
  Label editor (enter '?' for help at any prompt)
  > p
  OpenBSD area: 64-251658225; size: 251658161; free: 209728575
  #                size           offset  fstype [fsize bsize  cpg]
    a:         38812976               64  4.2BSD   2048 16384 38128
    b:          3116610         38813040    swap
    c:        251658240                0  unused
  > a
  partition: [d]
  offset: [41929650]
  size: [209728575]
  FS type: [4.2BSD]
  Rounding offset to bsize (32 sectors): 41929664
  Rounding size to bsize (32 sectors): 209728544
  > p
  OpenBSD area: 64-251658225; size: 251658161; free: 31
  #                size           offset  fstype [fsize bsize  cpg]
    a:         38812976               64  4.2BSD   2048 16384 38128
    b:          3116610         38813040    swap
    c:        251658240                0  unused
    d:        209728544         41929664  4.2BSD   2048 16384    1
  > w
  > q
  No label changes.
  #
  

• Create a filesystem on the new slice:

  # newfs /dev/rwd0d
  /dev/rwd0d: 102406.5MB in 209728544 sectors of 512 bytes
  506 cylinder groups of 202.47MB, 12958 blocks, 25984 inodes each
  super-block backups (for fsck -b #) at:
   32, 414688, 829344, 1244000, 1658656, 2073312, 2487968, 2902624, 3317280,
   3731936, 4146592, 4561248, 4975904, 5390560, 5805216, 6219872, 6634528,
   7049184, 7463840, 7878496, 8293152, 8707808, 9122464, 9537120, 9951776,
   ...
   [snip]
   ...
   193229728, 193644384, 194059040, 194473696, 194888352, 195303008, 195717664,
   196132320, 196546976, 196961632, 197376288, 197790944, 198205600, 198620256,
   199034912, 199449568, 199864224, 200278880, 200693536, 201108192, 201522848,
   201937504, 202352160, 202766816, 203181472, 203596128, 204010784, 204425440,
   204840096, 205254752, 205669408, 206084064, 206498720, 206913376, 207328032,
   207742688, 208157344, 208572000, 208986656, 209401312,
  #
  

• Migrate /home

  Here, we mount the root filesystem (which contains the old /home), and also the new filesystem, and finally migrate the data from old /home to new space.

  # mount /dev/wd0a /mnt
  # mount /dev/wd0d /mnt2
  # (cd /mnt/home; tar cf - .) | (cd /mnt2; tar xpf -)
  # rm -rf /mnt/home
  # mkdir /mnt/home
  

  Note, the tar command above is a nice platform independent way of copying everything from one directory to another, preserving everything (permissions, etc…). The cp command is different on Linux and the *BSDs, yet tar, used in the above fasion, is identical on Linux, FreeBSD, NetBSD, and OpenBSD. I thank Todd Fries of Free Daemon Consulting for teaching me that one.

• Mount on boot

  The following command will add the new /home to your /etc/fstab so it is automatically mounted upon boot.

  # echo "/dev/wd0d /home ffs rw,softdep 0 1" >> /mnt/etc/fstab
  

• Clean up:

  # umount /mnt*
  # reboot
  

  Now enjoy the extra space!

At ARP Networks, sometimes we have to resize an OpenBSD root partition to satsify a customer requirement, template requirement, or something else along those lines.

I’ve sometimes seen customers struggle to do this themselves, so the following is an example of how I resized a root partition from 5 GB to 9 GB, leaving 1 GB for swap. The underlying volume was already expanded from 5 GB to 10 GB, to give us room to do this.

So, let’s get to it.

• Boot into the system’s rescue disk:

  > boot bsd.rd
  

  Then select (S)hell at the prompt.

• Resize:

  Grab the growfs(8) program from the root partition. This isn’t included with the rescue disk, for some reason.

  # mount /dev/wd0a /mnt
  # cp /mnt/sbin/growfs .
  # umount /mnt
  

  Re-initialize the MBR, using the entire disk.

  # fdisk -i wd0
  Do you wish to write new MBR and partition table? [n] y
  Writing MBR at offset 0.
  #
  

  Change the size of the slices.

  This system has only the root partition and swap. The idea is to remove the swap partition, then extend root, and finally put the swap partition back.

  # disklabel -E wd0
  # Inside MBR partition 3: type A6 start 63 size 20964762
  Treating sectors 63-20964825 as the OpenBSD portion of the disk.
  You can use the 'b' command to change this.
  
  Initial label editor (enter '?' for help at any prompt)
  > p
  OpenBSD area: 63-20964825; size: 20964762; free: 9446220
  #                size           offset  fstype [fsize bsize  cpg]
    a:         10490382               63  4.2BSD   2048 16384    1
    b:          1028160         10490445    swap
    c:         20971520                0  unused
  > d
  partition to delete: [] b
  > p
  OpenBSD area: 63-20964825; size: 20964762; free: 10474380
  #                size           offset  fstype [fsize bsize  cpg]
    a:         10490382               63  4.2BSD   2048 16384    1
    c:         20971520                0  unused
  > c
  partition to change size: [] a
  Partition a is currently 10490382 sectors in size, and can have a maximum
  size of 20964762 sectors.
  size: [10490382] 9G
  Rounding to cylinder: 18876312
  > a b
  offset: [18876375]
  size: [2088450]
  FS type: [swap]
  > p
  OpenBSD area: 63-20964825; size: 20964762; free: 0
  #                size           offset  fstype [fsize bsize  cpg]
    a:         18876312               63  4.2BSD   2048 16384    1
    b:          2088450         18876375    swap
    c:         20971520                0  unused
  > w
  > q
  No label changes.
  #
  

  Grow the filesystem using growfs(8)

  # growfs /dev/wd0a
  We strongly recommend you to make a backup before growing the Filesystem
  
   Did you backup your data (Yes/No) ? Yes
  new file systemsize is: 4719078 frags
  Warning: 216792 sector(s) cannot be allocated.
  growfs: 9111.1MB (18659520 sectors) block size 16384, fragment size 2048
          using 45 cylinder groups of 202.47MB, 12958 blks, 25984 inodes.
  super-block backups (for fsck -b #) at:
   10781088, 11195744, 11610400, 12025056, 12439712, 12854368, 13269024, 13683680, 14098336, 14512992, 14927648, 15342304, 15756960, 16171616, 16586272, 17000928, 17415584, 17830240,
   18244896
  #
  

  Give it a rinse.

  # fsck /dev/wd0a
  ** /dev/rwd0a
  ** Last Mounted on /
  ** Phase 1 - Check Blocks and Sizes
  ** Phase 2 - Check Pathnames
  ** Phase 3 - Check Connectivity
  ** Phase 4 - Check Reference Counts
  ** Phase 5 - Check Cyl groups
  100205 files, 418854 used, 4172217 free (97 frags, 521515 blocks, 0.0% fragmentation)
  
  MARK FILE SYSTEM CLEAN? [Fyn?] y
  
  
  ***** FILE SYSTEM WAS MODIFIED *****
  #
  

  And that’s pretty much it. Everything is done within OpenBSD’s rescue disk kernel bsd.rd, no need to have a separate CD-ROM / USB rescue disk utility.

WTF is going on here?

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(rdb:1) sum
244.4
(rdb:1) amount
244.4
(rdb:1) sum != amount
true
(rdb:1) sum.to_f
244.4
(rdb:1) amount.to_f
244.4
(rdb:1) sum.to_f != amount.to_f
true
(rdb:1) sum == amount
false
(rdb:1) sum.to_f == amount.to_f
false
(rdb:1)

First guess is some type conversion problem…

Still investigating.

I was recently using Jailkit on Ubuntu to set up a chroot environment for users of a backup storage server. I wanted to give the users the ability to check their quotas with the regular quota command.

I go about telling Jailkit that the chroot directory will need the quota binary. This should be all that is needed, or so I thought.

Upon checking a quota as a chroot’d user, it barfs the following error,

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$ quota
quota: Cannot open quotafile /home/aquota.user: Permission denied
quota: Quota file not found or has wrong format.
$

From what I can tell, this is a very misleading error message. The permissions of aquota.user are always 0600, readable / writable only by root. This can’t be changed, not even as root. Witness.

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-rw------- 1 root root 7168 2013-02-27 22:32 /home/bkusers/home/aquota.user

Using a bit of strace and some luck, I find what the quota command is really looking for is /proc/sys/fs/quota.

It simply does a stat() system call on that directory within proc, so if you simply do,

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$ sudo mkdir -p /home/bkusers/proc/sys/fs/quota

then the quota command works like a charm within the chroot environment.

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$ quota -s
Disk quotas for user testuser (uid 1007):
     Filesystem  blocks   quota   limit   grace   files   quota   limit   grace
       /dev/md3      16       0   3907M               4       0       0
$

My chroot directory in these examples was obviously /home/bkusers, modify accordingly for your needs.

Let me turn a corner and cover a non-technical topic here for once…

Several years ago, I had a job where I had to ask myself the following question, “Do I do what I think is right, or do I do what will make my new boss happy?”

Now, this was not a moral question, it was simply about how to do some measurements / benchmarking and systems stuff; pretty low key, no big deal.

I stuck to my guns and at some point shortly after, I didn’t have that job anymore. ;)

In my case, there really wasn’t any big life altering changes to myself or anyone else regardless of which decision I made. But in some cases, this can really go the wrong way…

Let me illustrate by quoting something from my reading last night; the book was Amy Goodman’s (Host of Democracy Now!) ”Breaking the Sound Barrier”, and within was a quote from Grammy Award-winning soul singer John Legend when he gave the commencement address at the University of Pennsylvania,

Too often, in business and in government, people are rewarded for having the answer that the person they report to wants them to have: “Yes, sir. We can provide mortgages to people who have no down payment and can’t afford the monthly payments.”… “Yes, ma’am. I can write a legal brief to justify torture.”

Stick to your guns, fuck your boss.

I’m proud to say I’ve dusted off this blog and migrated from Mephisto to Octopress. Now I can actually post new content (the old Mephisto system got so dated and went to dependency hell that I was hardly able to do anything besides keep the static cached files up).

I’m going to try to go through all the posts and cleanup / fix any loose ends. So far the import went pretty smooth and I’ve only burned a few hours (instead of a whole weekend).

I was unable to successfully import the comments, so those will be gone forever. Most were spammy anyway, and any comments posted at least within the last year or two use Disqus, and those are still around.

I’d like to get my usual theme working again, but alas, that is very low priority right now. Perhaps a new look is warranted anyway. However, at least, I can move away from the default theme. Gotta read more docs…

Let me know if anything is out of the ordinary.

Thanks!

Testing 1 2 3…

is this thing on?

Here’s a quick post on how to get OpenBSD 4.5 working as a KVM guest on kvm-84, the version that ships with Jaunty.

Unlike OpenBSD 4.4, which worked out of the box, 4.5 made some changes in their kernel with respect to interrupts that may have exposed bugs in KVM/QEMU. The workaround is to disable mpbios within the OpenBSD kernel. This will affect SMP guests adversely, so it isn’t for everyone.

Your kernel is affected by this if you boot and it hangs at:

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setting tty flags

Credit goes to Todd Fries of Free Daemon Consulting, LLC for figuring this out and passing down the wisdom onto me.

Note: I’m using a 64-bit host as well as the 64-bit version of OpenBSD as the guest.

Step 1

Boot the OpenBSD 4.5 install CD within your blank VM and proceed through the entire install normally. Then, reboot from the hard disk but stop at the boot prompt…

Step 2

At the boot prompt, perform the following:

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boot> bsd -c
...
UKC> disable mpbios
 54 mpbios0 disabled
UKC> quit
...

System will now boot normally.

This has temporarily disabled mpbios and will not persist across reboots. You now have to make this change permanent in the OpenBSD kernel, as illustrated in the next step.

Step 3

Login to your new system as root and perform:

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# config -ef /bsd
OpenBSD 4.5 (GENERIC) #2052: Sat Feb 28 14:55:24 MST 2009
    deraadt@amd64.openbsd.org:/usr/src/sys/arch/amd64/compile/GENERIC
Enter 'help' for information
ukc> disable mpbios
 54 mpbios0 disabled
ukc> quit
Saving modified kernel.
#

Now your system will boot up normally from this point onward.

Moved this blog to a new and faster server. Maybe now I’ll start posting again, since the admin section isn’t slowed to a crawl any more with spam comments. :(

If anyone notices anything missing, blow up, etc… Please leave a comment. Thanks!

I recently was working with some code that had an onClick event handler on the <TR> of each row of a table. In one of the columns, a <TD>, there were icons that also had onClick’s on them. Something like:

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<table>
  <tr onClick='foo()'>
    <td onClick='bar()'>
      <!-- some icons -->
    </td>
    <td></td>
    <td></td>
    ...
  </tr>
</table>

Now if the icons in the first <TD> were clicked, I wanted bar() to fire, but not foo(). Normal behavior is to execute them both.

Turned out there is a simple solution for this with jQuery. Only tested in Firefox, but presumably this works across the board because jQuery is awesome that way.

Add a class to the <TD> called no-event-bubble-up:

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  <td onClick='bar()' class='no-event-bubble-up'>

And add the following JS to your page:

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<script type='text/javascript'>
  $(document).ready(function() {
    $(".no-event-bubble-up").each(function() {
      $(this).click(function(e) {
        e.stopPropagation();
      });
    });
  });
</script>

That’s all that is needed and it worked for me.

Let me know if you find this useful.