[SO]HO Software RAID5 server: which implementation should I choice?

[Nenhum_de_Nos]

On Wed, Apr 9, 2008 at 9:47 AM, Arnaud Houdelette
<arnaud.houdelette at tzim.net> wrote:
> Lev Serebryakov a écrit :
>
>
>
> > Hello, freebsd-stable.
> >
> >  Does somebody use some software RAID5 on FreeBSD in real production
> >  system?
> >
> >  I want to build storage server for my home: RAW photos, multi-layer
> > PhotoShop files and FLAC-encoded music consume a lot of space, and
> > they should be availible both from desktop & notebook.
> >
> >  Also, all photo-content is unique, so I need some insuranse from
> > single HDD crash. I understand, that I will not safe from fire, PSU
> > failure and thing slike this.
> >
> >  I selected hardware platform: Intel Q35-based MoBo with 6xSATA-II ports
> > (all of them is chipset-based, so no SiliconImage/JMicron/Whatever
> > crappy controllers), some low-end Core2Duo, 2Gb of memory.
> >  Storage will be 5x500Gb WD HDDs for RAID + one small HDD for boot,
> system,
> > swap, etc. I want to have 2Tb (ok, not real Tb, I know) of "protected"
> > storage.
> >  I want to have maximum speed via 1Gb network, because graphic files
> > are big and should open fast. Not as fast as local ones, I understand
> > that, but speeds about 12-15Mb/s is not enough for sure :)
> >
> >  Only problem I see: which software RAID5 solution should I prefer?
> > FreeBSD-based, of course!
> >
> >  I see these variants:
> >
> >  (1) FreeBSD 6(7?) + graid3. Slow, one disk for checksums is bottleneck,
> >     as far as I understand.
> >
> >  (2) FreeBSD 6(7?) + gvinum/radi5. Is it stable enough?! Is it complete?
> >     when I try it about 6 months ago in VMWare installation with 5
> >     virtual disks, I got panics and strange behaviour after "crashing"
> >     one of virtual disks.
> >
> >  (3) FreeBSD 6(7?) + graid5. Again, is it stable enough? There are
> >     THREE versions of it. Which one should I prefer? There was long
> >     thread about it some times ago without any clear conclusion. Does
> >     something changed?
> >
> >  (4) FreeBSD 7 + ZFS "zraid". And again: stability. Too many messages
> >     about locks, crashes, etc. Code is experemental. Is it only for
> >     32 bit systems?
> >
> >  (5) Do I miss something?
> >
> >  (6) Solaris + ZFS? I don't want it, I know a little about Solaris
> >     administaration, and I already have FreeBSD servers and routers.
> >
> >  I know, that 3ware or Areca controllers are very good. I know, that
> >  "gmirror" is very stable. But these variants are too expensive for
> >  home server :(
> >
> >  Does somebody use some software RAID5 on FreeBSD in real production?
> >  Any advices?
> >
> >
>
>  Hi !
>
>  I personally use the 3 option for my personal Home File Server. I got
> approximatly the same usage for the file server (mostly video, music,
> photo). I built my own about 12 month ago.
>  I reviewed the about the same variants as the one you propose :
>  (1) Discarded for performance issues. Raid3 is slow. Really.
>  (2) raid5/vinum is also slow. And as I understood at that time,  recovery
> from lost hard drive wasn't easy enough for the freebsd niubee I was  then.
>  (4) ZFS wasn't there yet. But I did test it on a test VMWare, and wasn't
> convinced (mostly stability and memory issues).
>
>  So I use geom_raid5. I sticked to the main distributions, which seemed more
> stable at the moment. The kernel module is fairly simple to build/install.
> Performance is (very) good for a software raid.
>  I successfully switched the raid array from an i386 6.2-RELEASE to an an
> amd64 7.0-RELEASE (with motherboard and CPU change) without any assle.
>
>  For the moment, I use one big UFS+SU (and snapshots) on the whole array. I
> successfuly tried unpplugging then replugging on of the drives, suddent
> power loss, using the array with a missing disk (degraded mode). All did
> work fine. (still, I use an UPS on the file server).
>
>  The sole issue I had is with ataidle. I had to patch ata-disc.c to increase
> the IO timeout. Without, the raid5 module detected temporary disk loss and
> constantly launched rebuilds of the array.
>
>  With 7.0, I wondered if I should use gjournal, but I'm not sure if it's
> really the way to go on a file system dedicated to store many big files. So
> I stick to soft updates.
>
>  Current configuration is :
>  / on a 2GB usb key
>  /tmp on memory
>  ports and source trees (and some portsnap stuff) on a small disk
>  4x250 GB sata for the raid5 array.
>  AMD A64 3200+ and 512 GB DDRII
>  Realtek Gigabit nics.
>
>  Copy from raid5 to /dev/null gives about 100MB/s
>  Copy from /dev/random to raid5 about 40MB/s
>
>  I use samba shares. I get about 40MB/s in both ways from another computer
> on the network (enabling jumbo-frames gives a big boost).
>
>  Hope my own story can help you in any way.
>
>  Regards,
>
>  Arnaud Houdelette

I know its been quite some time from the mail, but if you could say
where to find this module. eikipedia says its on freebsd 7 but there
is not this module for me (/boot/kernel/ there is no raid5 file).
everytime I search the internet I find old stuff about it.

If you could point me the site/article/anything :)

thanks,

matheus


-- 
We will call you cygnus,
The God of balance you shall be