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

[Brian]

Nenhum_de_Nos wrote:
> 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
>
>
>   
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