my hardware? give me your opinion

[namboy]

Our office decommissioned several IBM Intellistation Z Pro workstations (model 9228), so I built two NAS boxes:
power supply 815 watts
2 Xeon cpu duel core 2.33GHz
8 Gb ram (kinda small, I know)
8 Seagate Barracuda 3Tb HDD sata 6 NCQ 64mb cache 7200 rpm
1 Intel Raid Controller RT3WB080

the disks are in a RAID50 configuration, so this yields 16.3Tb usable disk space. One NAS is version 8.3.1 and the other is 9.1. Our data access is via Windows CIFS.
The 9.1 box is used as PULL Rsync from the other box. I've enabled dedup and compression. I know it really doesn't have enough ram for dedup, but I don't care if it's slow because for now it's just a backup. And this old ram is getting expensive!

I guess what I'm asking from the forum: Do you see any big red flags with this hardware config?

 

[cyberjock]

ROFL! I see two right now:

#1
----------
Dedup is a big red flag.

Did you even read the manual on dedup? Enabling it has nothing to do with being slow. It has everything to do with needing 5GB of RAM per 1TB of disk space(and that's a thumbrule.. there is no upper limit)! And the first time you run out of RAM your system will panic. You'll reboot and find you are unable to use the pool again until you get enough RAM.

Here's the warning straight from the release notes for 8.3 which brought us dedup:

ZFS v28 includes deduplication, which can be enabled at the dataset level. The more data you write to a deduplicated volume the more memory it requires, and there is no upper bound on this. When the system starts storing the dedup tables on disk because they no longer fit in RAM, performance craters. There is no way to undedup data once it is deduplicated, simply switching dedup off has NO AFFECT on the existing data. Furthermore, importing an unclean pool can require between 3-5GB of RAM per TB of deduped data, and if the system doesn't have the needed RAM it will panic, with the only solution being adding more RAM or recreating the pool. Think carefully before enabling dedup! Then after thinking about it use compression instead.

So don't be offended when I say that using dedup is irresponsible and you should just delete your data now if you really think that using dedup is smart for your system. For all but probably 20 people on the forum, using dedup at all is irresponsible. Any money you think you'll save on disk space you will certainly spend on buying enough RAM. Even a "small" 10TB array would need 50GB of RAM and that's not cheap!

#2
---------
Why on god's green earth are you using a RAID50 with ZFS. You shouldn't ever mix ZFS with hardware RAID, ever.






So now that begs another question.. did you even bother to read the manual? Cause you've broken 2 major cardinal rules with FreeNAS with your poor misconfigured system.

 

[namboy]

Well, this is the feedback I wanted! I did use the manual when setting this up, but just didn't catch the point to not use hardware RAID with ZFS (my bad). I just finished the 'guide' and it seems I have the bare minimum RAM, but I can't really change that now. But, what to do with the RAID card? Should I configure it as a basic hard-drive controller card, all drives independent? Then, in FreeNAS setup 2 VDev (RAIDz2) with 4 disks each?

Clearly, do not use dedup, only compression.

 

[namboy]

hmmm ... looks like I wasted a bunch of $ on a nice Intel RAID card if I'm just going to configure it as JOBD! Reading "Confused about LSI" right now! yep, I am.
no ZIL and no L2ARC either as I don't have space for any more disks.

 

[cyberjock]

If it supports JBOD and SMART works with the disks that's what you need to do. If it doesn't work, then you need to look at buying another controller. The M1015 reflashed to IT mode is the cheapest and best solution you will find for 8 drives.

 

[namboy]

Ok, so let's flip this around. For a new, 3rd NAS, and using the same IBM case, processors and power supply ....
AND knowning the data storage is for large files ( satellite imagery), not lots of random IO
1) upgrading to 16Gb of RAM
2) buying the IBM M1015 - as the Intel card cannot do JBOD
3) ? what HD configuration ? 8 drives all the same or a couple of drives that are small & faster for use in ZIL or L2ARC

Since I have two of the incorrect controller cards, I'm going to have to rebuild one of these, get the data off, then rebuild the other. So, I could reconfigure the hard-drives for better performance while I'm in there. The one hard drive limit is 3Tb.

 

[cyberjock]

So you probably don't need a ZIL or L2ARC. Spend money on those only after you've proven you need them.

I'd do 8 drives in a RAIDZ2.
Keep the 16GB of RAM and the M1015.