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
