Recent Journal Comments

Following your description i wanted to trigger a particular reaction when i insert a memory stick.

However, i have no directory /etc/hotplug on my fedora 8 machine, even though 'locate hotplug' shows lots of kernel modules like for instance /lib/modules/2.6.25.11-60.fc8/kernel/drivers/pci/hotplug/acpiphp.ko

Do i have to do some sort of installation or configuration to get it running?

Thank You
Jody
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If I want to do something similar with an ipod touch, i think what I need to do is first set up udev to recognise the ipod and create a /dev/ipod link. Then, set up a mapping that will mount /media/ipod to /dev/ipod and have an ipod hotplug script perform the mounting/unmounting.

Does that sound about right?
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Sean
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On the other hand, while my storage server has been really stable under Linux+FUSE+ZFS, the other server I was trying to set up totally fell over and lost all the data on the ZFS. That's never happened under OpenSolaris.

So, I don't have a lot of data, but it seems like the average case is better under Linux, but the worst case is much worse.

Sean
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So-far, it's nice and easy to administer and I'm testing it to see if the performance is same/better/worse than ReiserFS on Linux for the "lots of small files" case. I'll chime-in when I have more benchmark info.

Q: Any comments on stability of ZFS on linux versus OpenSolaris Sean?

- Steve
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It's an interesting idea, but I'm still not sure if it makes my common use of Firefox any better.

Plus, the other down-side is that if I switch to other browsers, which I sometimes do, they are now even further from the set of commands I'm using.

Sean
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- Steve
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The card I'm talking about here is not such a card. My intended use was with ZFS, which implements better RAID than any hardware RAID solution, so I intentionally avoided any hardware RAID in this situation.

The hardware I am using has mostly been fine. The only issue I've had so far was that we had a brief power outage one day, and when that happened it seems that the SATA port multiplier freaked out and I lost access to a couple of the drives. A power-cycle resolved that, and another brief power outage did not impact it, so it must have been some sort of issue that made it past the UPS and into the controller.

Sean
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ive not played with sata raid yet but have alot of scsi experience.

are the sata cards a software raid? or hardware? do you have to use the linux software raid or is it done invisibly through the hardware?

and how has your experience been with the hardware so far?
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Sean
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   http://fedoraforum.org/forum/showthread.php?t=192585

There are lots of discussions about laptop displays (which I didn't follow because my setup is for a desktop).

Regarding the problem with sessions, I too like using FVWM and so was disappointed that the old solution using .Xclients is no longer supported. Some googling let me to learn about the need to install the

   xorg-x11-xinit-session

package which I learned about here:

   http://docs.fedoraproject.org/release-notes/f9/en_US/sn-Desktop.html

The only nit with this is that I have to remember to select the 'User script' session whenever I log in. If there's a better solution I'd love to learn about it.
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As far as the Silicon Image 3114 chipset, I initially started with those but had problems. That chipset only works with the non-RAID version of those boards, but all the boards I found had the RAID bit set. This may have been fixed since, but getting it working under OpenSolaris at the time required re-flashing the BIOS on the board, which I had no luck at. This is one of the benefits of running ZFS under Linux that I mentioned: Much more hardware support. If you want to have the option of running under OpenSolaris, you'll want to pick another board. My current system is not capable of running directly under OpenSolaris I'd expect.

As far as details about the setup, I plan to write up more on this soon. However, one of the cards I'm using is the one I wrote about a few days ago. Another is the Supermicro 8-port SATA PCI-X card. And finally I'm using 4 ports on the motherboard.

Sean
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Thanks for such an informative post. I have long been interested in ZFS+Linux, and really appreciate a post from someone who has worked with it in production.

I may be building a big fileserver soon-- would you mind sharing details about your hardware (case, mobo, and sata cards)?

Thank you.
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Just wondering whether your set-up is 32bit or 64bit? I've heard ZFS is less buggy in 64bit
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The Sun HCL listed a SATA card with a SI 3114 chipset; do those not work in your experience? 'Cause those are a dime a dozen.
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I have been pining for ZFS since I first heard about it. I did some research for a while into what would be required to make truly robust backups for current filesystems, and it is not pretty. ZFS does nearly everything the right way, but I'm very hesistant to use a beta-release of something as important as a filesystem!
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Also note that, from what I can tell of TrueCrypt, the hidden volume support is fairly limited. First of all, you can only create a hidden volume in the contiguous free area at the end of the disc. So you have to make sure that the volume you are creating the hidden volume in has all the data moved to the front, and that just screams "hey, there's a hidden volume in here". Also, it sounds like there is no provision for mounting and aging the outer volume (because that would potentially create files in the hidden volume), so anyone looking at it would see that, hey, this was formatted and confidential looking files placed on it, but hasn't been mounted in 8 months. But I see the system is booted every day...

You're also limited in the file-system types you can put on the outer volume, of course. It needs to be something that can be defragmented to all be at the front of the disc. ext3 with it's cylinder groups and lack of defrag would severely limit the size of the contiguous free space at the end of the disc.

The concern I have about partial encryption on a system is that it may result in information being leaked. For example, information stored in a database, or if updatedb runs and is not configured to ignore the encrypted partitions, an attacker now has a list of the file names and locations. "What is this "HowToCheatTheIRS" file?" "Oh, it's a joke my buddy sent me." "Uh huh. And why did you put it on your encrypted partition?"

I ran with just my /home partition encrypted for a while, and tried to put things like the updatedb and my PostgreSQL databases (which store confidential company information) on it, but it was just too hard to say for sure that nothing was getting leaked. That's why I went to a "everything but /boot is encrypted" model.

So, yes, TrueCrypt is cool and has some limited features along these lines, you don't get the same benefits as combining the crypto with the file-system. And while neither my mechanism nor TrueCrypt hidden volumes are available on Linux yet, it seems likely that TrueCrypt will be available before mine is. :-)

Note that there are several other crypto systems available that also support similar "hidden volumes". See the Wikipedia article on Steganography for links to more options.

Sean
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