OpenBSD Journal

Softraid experiences with OpenBSD 4.2-current

Contributed by jl on from the zip-to-my-lou dept.

Will Backman writes:
It had been a few months since I had experimented with softraid in OpenBSD, so I though I would give it a try and see how far it had progressed. I have been using bioctl with hardware raid and was quickly won over by the elegance of the tools, and I looked forward to managing software raid with the same simplicity.
Just to be difficult, I dragged an old dual 450mhz Apple Power Mac out of storage and connected a USB and IDE iomega Zip drive to function as my raid volumes. Unfortunately SMP isn't supported by OpenBSD on the PPC platform yet, but everything else was detected and functioning correctly.
Softraid is enabled in current snapshots, so there was no need to compile a custom kernel.
The man page for softraid(4) is sufficient to get started, although I did add some suggested extra steps just to make sure.

The first step was to mark the zip drives as raid volumes. The disklabel(8) commands in the man page didn't work correctly for me on PPC because fdisk(8) creates an additional small MS-DOS volume, so I had to manually set the proper offset in disklabel for the RAID portion of the disk.

Once each zip disk had a RAID partition, I was able to use bioctl to create a new volume, and at that point it appeared as just another SCSI drive. I continued to follow the steps in the man page, mounted the RAID volume, and started writing and verifying data. Both RAID0 and RAID1 worked great, although I needed to use dd(1) to wipe out the beginning of zip disks to make sure all the softraid metadata was really gone before trying to re-use a disk in a new RAID set.

Of course, given my hardware choices, performance was terrible, but it hadn't corrupted data or caused a kernel panic. I was happy to see that the kernel now recognized the RAID metadata on the ZIP disks at boot and automatically assembled them for me. I even tried swapping the zip disks, and the kernel picked up the change and notified me that it had found a "roaming device". If I brought the system up with one disk ejected, it gracefully noticed the problem.

Unfortunately, softraid cannot yet recover from failure or automatically rebuild after an unclean shutdown, but I can see great signs of progress. I really look forward to a supported alternative to raidframe(4), and I'm excited to have the same management tools for both my hardware and software RAID. I'm also looking forward to seeing what unusual features the developers come up with, and the source tree is already leaving some interesting clues.

(Comments are closed)

Comments

  1. By Anonymous Coward (24.37.242.64) on

    What's the advantage of softraid vs ccd and RAIDFrame? Just curious as to why the change?

    Comments

    1. By Anonymous Coward (124.244.200.136) on

      > What's the advantage of softraid vs ccd and RAIDFrame? Just curious as to why the change?

      Yes, i want to know too, what is different between (soft)raid0 and ccd?

      Comments

      1. By Brad (2001:4978:104:3:216:41ff:fe17:6933) brad at comstyle dot com on

        > > What's the advantage of softraid vs ccd and RAIDFrame? Just curious as to why the change?
        >
        > Yes, i want to know too, what is different between (soft)raid0 and ccd?

        softraid has a number of advantages including being easier to setup, use and maintain. It has a smaller and cleaner code base making it easier to maintain the code and add features to as well as being enabled by default unlike RAIDframe. It supports multiple RAID disciplines unlike ccd. It will support encrypted arrays. It will support ATA over Ethernet. Who knows what else is coming down the pipeline. Also RAIDframe was never officially supported. Personally I would never use ccd or RAIDframe. Both will be removed in good time once softraid is fairly mature.

        Comments

        1. By Anonymous Coward (24.37.242.64) on

          > > > What's the advantage of softraid vs ccd and RAIDFrame? Just curious as to why the change?
          > >
          > > Yes, i want to know too, what is different between (soft)raid0 and ccd?
          >
          > softraid has a number of advantages including being easier to setup, use and maintain. It has a smaller and cleaner code base making it easier to maintain the code and add features to as well as being enabled by default unlike RAIDframe. It supports multiple RAID disciplines unlike ccd. It will support encrypted arrays. It will support ATA over Ethernet. Who knows what else is coming down the pipeline. Also RAIDframe was never officially supported. Personally I would never use ccd or RAIDframe. Both will be removed in good time once softraid is fairly mature.

          UltraAwesome stuff! Sweet! :)

        2. By Anonymous Coward (85.178.83.152) on

          > > > What's the advantage of softraid vs ccd and RAIDFrame? Just curious as to why the change?
          > >
          > > Yes, i want to know too, what is different between (soft)raid0 and ccd?
          >
          > softraid has a number of advantages including being easier to setup, use and maintain. It has a smaller and cleaner code base making it easier to maintain the code and add features to as well as being enabled by default unlike RAIDframe. It supports multiple RAID disciplines unlike ccd. It will support encrypted arrays. It will support ATA over Ethernet. Who knows what else is coming down the pipeline. Also RAIDframe was never officially supported. Personally I would never use ccd or RAIDframe. Both will be removed in good time once softraid is fairly mature.

          Encryption? HW Accelerated? Wich algorithms?
          Also: So RaidFrame and ccd get kicked out then? :)

          Comments

          1. By henning (213.39.202.162) on

            > Also: So RaidFrame and ccd get kicked out then? :)

            we'll decide that when the time is right, which is neither now nor tomorrow nor next week nor next month.
            you don't need much of a vision to see raidframe departing once softraid grew rebuild support and has been around for a bit tho

    2. By dingo (68.30.176.132) on

      > What's the advantage of softraid vs ccd and RAIDFrame? Just curious as to why the change?

      do a wc -l *.c for the raidframe code.

  2. By Anonymous Coward (76.68.211.86) on

    softraid is too new to use on a production system.

    Comments

    1. By Brad (2001:4978:104:3:216:41ff:fe17:6933) brad at comstyle dot com on

      > softraid is too new to use on a production system

      Wow, you're a real brainic. How long did it take you to figure that out?

      Comments

      1. By Anonymous Coward (72.0.206.213) on

        > > softraid is too new to use on a production system
        >
        > Wow, you're a real brainic. How long did it take you to figure that out?

        You son of a bitch.

        Comments

        1. By Anonymous Coward (68.150.143.243) on

          > > > softraid is too new to use on a production system
          > >
          > > Wow, you're a real brainic. How long did it take you to figure that out?
          >
          > You son of a bitch.

          Hey, his mom's not that bad, be nice to her.

        2. By Brad (2001:4978:104:3:216:41ff:fe17:6933) brad at comstyle dot com on

          > > > softraid is too new to use on a production system
          > >
          > > Wow, you're a real brainic. How long did it take you to figure that out?
          >
          > You son of a bitch.

          Thank you very much. How kind of you.

    2. By phessler (209.204.157.101) on

      > softraid is too new to use on a production system.

      did you notice that the submitter was putting this on a macppc "out of storage" and was putting softraid on a pair of zip disks? which part screams 'production'?

    3. By Anonymous Coward (199.42.80.225) on

      > softraid is too new to use on a production system.

      Why? I set it up on a production system last week 'cause I wanted to test it and didn't have any other boxes available. If something blows up, I'll just restore a backup (since RAID is no substitute for regular backups). What's a little outage among friends?

    4. By Mathieu Sauve-Frankel (222.0.65.5) msf@kisoku.net on

      > softraid is too new to use on a production system.

      raidframe is too bit-rotted to use on a production system.

      Comments

      1. By Anonymous Coward (72.0.206.213) on

        > > softraid is too new to use on a production system.
        >
        > raidframe is too bit-rotted to use on a production system.

        would you recommend someone use ccd for implementing a RAID0 solution at this time? will it not be phased out by softraid in a year's time?

        Comments

        1. By Anonymous Coward (76.250.126.209) on

          I'd say softraid raid 0 is basically good to go as is. I'd run it over ccd.

      2. By Anonymous Coward (2001:6f8:94d:5::2) on

        > raidframe is too bit-rotted to use on a production system.

        I disagree here. I'm actively using RAID 0, 1 and 5.

        .oO(raidctl -A {yes,root} rules)

  3. By Simon (192.44.85.23) on

    Wow that sounds like a nice new feature and I'm impressed that it works with such a funny setup ;-)

Latest Articles

Credits

Copyright © - Daniel Hartmeier. All rights reserved. Articles and comments are copyright their respective authors, submission implies license to publish on this web site. Contents of the archive prior to as well as images and HTML templates were copied from the fabulous original deadly.org with Jose's and Jim's kind permission. This journal runs as CGI with httpd(8) on OpenBSD, the source code is BSD licensed. undeadly \Un*dead"ly\, a. Not subject to death; immortal. [Obs.]