SOHO Raid 5 Setup - Suggestions/Questions

[manitcor]

My career and personality make me a natural data whore. Everything from high res videos to installs of enterprise apps and IDE (WebLogic, WebSphere, Oracle, etc). Over the years I have increased storage when and where I can. At this point I am running a very risky JBOD setup on 2.4ghz Core 2 Duo box on an intel D33 board (not the best but I picked up the box from a CompUSA that was going out of business for $400). Array size is about 1.2tb and I'm at about 80% utilization. Obviously the thought of loss is freaking me out and the on-board Controller is admittedly flaky.

The system is primarily a file-server/streaming/transcoding for the internal network but also does double duty as an app server/general purpose machine from time to time. The system is connected to the network via 2x1gigabit Ethernet and serves both PC clients as well as 4 separate media centers (Linux boxes hooked up to TVs running XBMC).

The need here is to be able to have video streaming while not impacting general file system perfromance and vice-versa. Someone should be able to sit down and use the machine (say compile an App in Eclipse or Visual Studio, run a VM, etc) while someone else is watching a video in the living room or accessing files off the array.

I have done some digging around the net, including here and I THINK I have layed out a good setup for a SOHO Raid 5 array. Though honestly I would love to have some opnions from folks who likely do this WAY more than I do.

My thought is the D33 board I have with a 1088 FSB and 4gb of ram on the 2.4ghz Core 2 Duo processor is plenty of horsepower. It's a Micro-ATX board but has plenty of PCI-x slots for my purposes. I'm not interested in a hard core gaming box here. The included NVida 256mb PCIx16 card will suit my needs more than adequately. I don't see a lot of issues with the motherboard itself. The case is more consumer oriented (gateway brand) so that will have to go.

My plan is to purchase a new case, power supply, Raid controller and 4 SATA hard disks and build using the existing Mobo, Ram, Proc and Vid card. Cooling of course is of critical importance here.

I am considering the following gear:

Antec P180 Case with additional Optional 120mm fans
Antec Neo Power 650 PSU
Adaptec 3805 SATA Raid Controller
4x 1tb Segate Baracudda 7200 RPM 32mb cache drives (total of approx 3tb when configured Raid 5)

The array will be data only and I will use 2 of the existing Western Digital 500gb drives as OS drives in a Raid 1 configuration using either the On-board controller or the new controller (not sure yet).

So far best price I have on this is about $1300 shipped.

A few questions I have about this setup are:

1. With 5 120mm fans on this case and 6 total drives in the case will I still have cooling issues with an average ambient temp of 75* F? Should I consider water cooling?

2. Is a 650w PSU enough? I assumed I would need 850 but ran a few online calculators and most came in at about 550w needed for a config like this.

3. I plan to go for the 128mb version of the 3805 would it be worthwhile to get the 256mb cache?

4. What is the value of the battery backup unit for the 3805? I have seen conflicting information on its use for maintaining the write cache for performance and reliability reasons.

5. Am I missing anything? Other than the standard warnings does this have some unseen potential to blowup in my face due to some of my choices? Are there any more cost effective options? Any other advice is welcome.

Thanks for reading my long post. I appreciate any input or insight anyone can offer.

 

[chookman]

1. No you dont need water cooling 5x120mm fans will push plenty of air.

2. Hard drives dont take up much power and a dual core with a low end GPU isnt going to use much power either 650w will be more than enough. In constrast im running Q6600, low end GPU and 10 hdd's off a 650w

3. I have the 3805 as well the 128mb version is doing me great and from the reviews that ive seen the 256mb version doesnt add much extra performance, however, the higher model with more ports may require it.

4. A UPS on the machine will limit the battery backups worth on the RAID card, however, it still protects again OS failure. Somejoe7777 is the best for explaining this.

5. Make sure you get the cables for the RAID card, they are SAS to SATA fanout cable, you get one with the retail box but not 2 that you may require should you upgrade or put your other drives on the controller.

Personally, i would get a different case. When i first bought my "fileserver" i got an Antec Titan that i thought would be plenty big, however, once you upgrade and put more drives in it became a nightmare. I ended up getting a Lian Li A70 for mine, supports 10 internal HDD's and comes with 6x120mm fans. HDD's have never been cooler.

EDIT: BTW its 1066FSB and PCI-e not -x

 

[manitcor]

Thanks for the advice and taking the time to answer my questions. As you can see it's been a while since I built a box (about 6 years). Been using laptops for a long time.

I like the Lian Li A70, I think I will either get that or it's replacement, the A77 for $50 more. The fan configuration alone is far superior to the Antec case I was looking at. Not to mention a boat load of space. The larger Antec cases did not support mATX boards however Lian Li seems to include mATX fitment in even their large cases. I can't believe I forgot about them as an option!

This system will be on a large APC UPS with auto-shutdown so no problems there.

Thanks again!

 

[chunkymonster]

The system is primarily a file-server/streaming/transcoding for the internal network but also does double duty as an app server/general purpose machine from time to time. The system is connected to the network via 2x1gigabit Ethernet and serves both PC clients as well as 4 separate media centers (Linux boxes hooked up to TVs running XBMC).

The need here is to be able to have video streaming while not impacting general file system perfromance and vice-versa. Someone should be able to sit down and use the machine (say compile an App in Eclipse or Visual Studio, run a VM, etc) while someone else is watching a video in the living room or accessing files off the array.

Given what you've spelled out here, you should consider building two seperate boxes, one for someone to sit down and use and a NAS to house your data and stream media.

Check out Freenas or Openfiler. I highly recommend FreeNAS.

 

[manitcor]

thanks chunkymonster. That is exactly what I want to do in the future. I wish I could do it now but I am pretty close to my budget cap so I doubt I can afford a new mobo, processor, nic, etc.

 

[manitcor]

Thanks for the suggestions and help. I wanted to update this thread incase anyone else was considering something similar.

You guys defiantly made me think some things over. As a result I did some more research into Raid5 and decided it was not for me. I saved up some more cash and went with a larger case and built the hardware from brand new components (ASUS Socket 775 board, Q6600 Proc with 8gb of 1088mhz ram). I kept the old box and upgraded it a bit as a separate general-use box.

One thing I have learned is that it is not a question of IF an array will fail. It is more a matter of when and how much risk you are exposed to in the event of a failure. After much thought and some extra cost I think I have a setup that minimizes my risks while still allowing me maximum flexibility with my storage.

I stuck with the 3805 w/ battery but boosted my drive count to 8 1tb drives in a RAID 6/0 configuration. This ends up with about the same amount of storage and performance as I was planning to get from the smaller RAID 5 setup but with a lot more redundancy against the inevitable bad writes and such. I can have up to 4 drives fail (2 on each side of the /0) before I have a major issue.

The Adaptec software does an excellent job re-verifying the array regularly and notifies me of any possible failures or pre-coursors to failure. I have already had one drive go due to SMART errors (IE it was not dead but SMART prediected failure within a few weeks). Fortunately Segate has excellent warranty replacement procedures that made getting a new drive a snap and with the high level of redundancy re-building the missing drive went off without a hitch. I also now keep 2 1tb drives in my office so I can very quickly swap in should another one fail rather than wait for a new drive from Seagate.

The software even allows for capacity upgrades very easily by swapping out larger drives one at a time and rebuilding with each drive. Not something I am planning to do in the near term though.

There is a ton of cooling in this box, eleven 120mm fans in total. Because of their size and placement in the case they don't need to run very fast to keep things very cool. So it is surprisingly quiet for such a large box.

I have finished the build and the system has run without a hitch since early October. If anyone is interested I will take some snaps of the finished product.

The only thing I might want to add in the future is possibly a second 3805 or better card so I can have a few drives in hot swap mode as well as to expand the overall array. Based on the adaptec docs I have read it is possible to do this but I haven't gotten into the details of it yet.

Eventually I would love to have a large tape drive for good incremental backups but the cost is just too high. For not I back things up to a few older 1tb external SATA drives that stay offline, except for backups. It's not the most ideal solution but better than nothing.


Thanks again for the good advice and thoughts.

 

[chookman]

"The software even allows for capacity upgrades very easily by swapping out larger drives one at a time and rebuilding with each drive. Not something I am planning to do in the near term though."

This will not work i dont think, to my knowledge the only way to increase while staying on the same array is to add more disks. Through OCE (takes a long time by the way) if you say slowly change out all your 1tb drives for 2tb ones the extra 1tb of all the drives is lost... to my knowledge anywho...

Nice to know it all worked out for you though, enjoy...

 

[enlightenment]

This should be possible. On geom_raid5, you can replace all disks of an array one at a time with a larget capacity HDD, and as such expand while the number of drives stay the same. Thus:

1. Swap out 250GB drive
2. Put in new 1000GB drive
3. Rebuild
4. Repeat step 1 for next drive
5. Once finished, a reboot/reload of the config will cause the raid5 driver to see 4 disks of 1000GB thus 3x 1TB= 3TB of storage, whereas first it was 4x 250GB.

Unless the raid driver imprints the volume size in the metadata, this should work with most raid5 drivers afaict.