New FreeNAS System - Hard Drives, Formats, Raid and other questions - Advice welcome

[Piggie]

Hi, I'm hoping I may find some kind people here that can advise me on a few things, and also offer some suggestions :)

I've just purchased a HP Proliant Microserver to run FreeNAS on so I can store files on it from my PC's at home.

So far all I have is the HP server, and FreeNAS 8.0 installed onto a 4GB USB2 Thumbdrive.

To make things easier, I'll number by questions in the hope perhaps some of you may be able to help/suggest/advice on the many points I'd like to ask on.

Note: My Machine is the HP Proliant Microserver:

1: I am thinking of buying four of these drives: http://www.scan.co.uk/products/2tb-...-green-sata-6gb-s-5900rpm-64mb-cache-12ms-ncq

Any thoughts?

2: I am looking to use the software RAID 5 in FreeNas for security and hopefully performance. Any reasons why not, and what did format should I use (do I have a choice?)

3: Given the above. How much memory should I have in my HP Microserver system? It only comes with 1GB of RAM as standard.

4: I will be booting with FreeNAS installed on a 4GB Memory stick. That's normal isn't it?

Are there many options I will have to select from as I'm adding volumes and selecting how I format the drives? or do I just leave everything at default sizes?
I'm thinking about things as cluster sizes etc etc?

I'm very new to all this so please be as basic as possible with any advice you may have.

Many thanks :)

 

[Adrian]

Hi, I'm hoping I may find some kind people here that can advise me on a few things, and also offer some suggestions :)
I've just purchased a HP Proliant Microserver to run FreeNAS on so I can store files on it from my PC's at home.
So far all I have is the HP server, and FreeNAS 8.0 installed onto a 4GB USB2 Thumbdrive.
To make things easier, I'll number by questions in the hope perhaps some of you may be able to help/suggest/advice on the many points I'd like to ask on.

A very popular machine. You know about the cash back offer?

I am a new user of FreeNAS, but have been running FreeBSD for a long time. I am currently set up with FreeNAS 8.0.1-BETA2, but am waiting a bit for more reports on BETA3 and further releases before reinstalling and cranking data onto the box.

1: I am thinking of buying four of these drives: http://www.scan.co.uk/products/2tb-...-green-sata-6gb-s-5900rpm-64mb-cache-12ms-ncq
Any thoughts?

Look OK. 4k sector size.

2: I am looking to use the software RAID 5 in FreeNas for security and hopefully performance. Any reasons why not, and what did format should I use (do I have a choice?)

I would go with ZFS. It has so many advantages. It is also preferred by the project. Your alternative is UFS, where you need to use GEOM to get RAID of any form.

3: Given the above. How much memory should I have in my HP Microserver system? It only comes with 1GB of RAM as standard.

At least 6 GB. Preferably 8 GB (the maximum). ZFS eats memory. Personally I would not consider using it on anything less than a 4 GB 64-bit system as you are then into a whole new world of tuning pain to resolve crashes caused by kernel memory problems.

4: I will be booting with FreeNAS installed on a 4GB Memory stick. That's normal isn't it?

Yes. Not all of it will be used.

Are there many options I will have to select from as I'm adding volumes and selecting how I format the drives? or do I just leave everything at default sizes?
I'm thinking about things as cluster sizes etc etc?

With ZFS and 4k drives (and I believe a recent enough BETA) a 4k block size check box will become visible when you select ZFS. Tick it as you will be having 4k drives.

Other choices are 1 (RAIDZ/RAIDZ1) or 2 (RAIDZ2) disks' worth of parity; and whether to have on line spares. With only 4 drives your options are limited. Another viable option would be 2 * 2 disk mirrors. Like RAIDZ2 this halves your capacity, but should have better performance.

 

[Piggie]

Hi, many many thanks for your excellent posting.

Oh yes, I know about the £100 cashback. One of the main reasons I went for it. I love a bargain :)

The reason I was drawn to those drives is they get excellent reviews all round and seem to be liked, and perform a little better than the ones I was going to do with. the WD Green ones.

Ok, so it's 4K Block and ZFS you recommend. Sounds like a Plan :)

To be honest, 8GB sounds crazy for such a system as it would be almost considered overkill for full blown windows, but hey, if that's what recommended, then I'm happy to go with it!
I don't pretend to understand why a tiny OS running a server/NAS needs 8GB.

I understand I don't need ECC memory and I've read that this will be fine: http://www.ebuyer.com/product/229102?gclid=CNu0-YvN2akCFcsb4Qod6FK_Mg
If you would care to recommend some other, then please do :)

I'm open to other suggestions when it comes to RAID. I always thought that RAID 5 was the "no brainer" one to go with. You lose just 1 drive out of 4 and you get good performance, with the ability that if one drive goes down you simply swap it for another and the new drive gets rebuilt automatically (I don't know how this works in reality)

But I'm open to other RAID's if there are problems with RAID 5

 

[Brand]

I'm open to other suggestions when it comes to RAID. I always thought that RAID 5 was the "no brainer" one to go with. You lose just 1 drive out of 4 and you get good performance, with the ability that if one drive goes down you simply swap it for another and the new drive gets rebuilt automatically (I don't know how this works in reality)

But I'm open to other RAID's if there are problems with RAID 5

You are not able to do RAID 5 with ZFS so you might want to read the ZFS Wikipedia article to get a quick intro to ZFS.

 

[Piggie]

Oh ok. I was under the impression that RAID Z1 was the same as RAID 5 and RAID Z2 was the same as RAID 6.
Using (wasting!) 1 or 2 drives respectively for parity information.

I shall take a read of that link you posted, thanks.

 

[Tekkie]

Its not wasting 1 or 2 drives its giving you that warm feeling that makes you sleep at night. ;)

FreeBSD doesn't need the 8GB of RAM, its the ZFS cache that eats it all.

 

[matthewowen01]

To be honest, 8GB sounds crazy for such a system as it would be almost considered overkill for full blown windows, but hey, if that's what recommended, then I'm happy to go with it!
I don't pretend to understand why a tiny OS running a server/NAS needs 8GB.

Every last drop of memory is used for disk cache. if it's read or written, it first went to the cache. this allows for massive speed improvements.

Oh ok. I was under the impression that RAID Z1 was the same as RAID 5 and RAID Z2 was the same as RAID 6.
Using (wasting!) 1 or 2 drives respectively for parity information.

it's very similar. all the benefits of raid5(6) without the write hole and other problems.

 

[Piggie]

Thanks to you both.
Yes, during the course of reading yesterday it's become apparent that the 8gb max that my HP micro server can use is what's defiantly needed, so I shall be ordering two sticks of memory tonight.

Also, yes I know it's not really wasted drives, I was just joking a bit. Officially my system has room for 4 drives. A fifth could be fitted into the top drive bay which is really meant for a cd rom unit, but for my home use, which is almost nothing in reality, I'm thinking perhaps the 4 will be ok.

I do often tend to go overkill for no reason on tech so I'm trying to hold myself back on this one!

I did read some issues about modern drives with 4k issues, but then I also read that freeness supports this 4k issue now, so perhaps that makes it a non issue?

I am still thinking of getting the four 2tb segate drives I linked to in my 1st posting.
If you feel this is wrong please say so.

I was going with the wd green ones, but then read some issues, plus the segate ones are a litte faster and run nice and cool with low power, so almost seemed a no brainer as they are just under £60 each.

 

[Bohs Hansen]

If you get the above named drives, first thing you should do when you get them is to check the serial number for firmware updates on Seagates page. There have been some problems with them in the first firmwares, but it should be resolved now. (and the old drives shouldn't be in stock anywhere anymore, but checking doesn't hurt).

Personally i went with the slightly more expensive SV35.5 Seagate drives. They are enterprise class and come with a 5 year warranty, but cost far from what normal enterprise class drives cost (like the WD RE f.ex.)

 

[Piggie]

If you get the above named drives, first thing you should do when you get them is to check the serial number for firmware updates on Seagates page. There have been some problems with them in the first firmwares, but it should be resolved now. (and the old drives shouldn't be in stock anywhere anymore, but checking doesn't hurt).

Personally i went with the slightly more expensive SV35.5 Seagate drives. They are enterprise class and come with a 5 year warranty, but cost far from what normal enterprise class drives cost (like the WD RE f.ex.)

Thanks for the advice. I had a look at the ST2000VX002 drives, which are the ones I think you mean, and may well go for them as the the extra £23 ish each, I guess it would be money well spent. Then again who knows with these things

 

[Bohs Hansen]

Yea, that are the ones. "Over here" they only cost around £12 more, so the choice was easy for me.

as we all know, every harddisk is a gamble .. it can run fine for 10 years, it can break down tomorrow. :) Wish you the best of luck anyway selecting your parts, I spend the better of 3month making up my mind :)

 

[Adrian]

Oh ok. I was under the impression that RAID Z1 was the same as RAID 5 and RAID Z2 was the same as RAID 6.
Using (wasting!) 1 or 2 drives respectively for parity information.

RAIDZ1/2 are not identical to RAID 5/6. They are similar in that they give up 1/2 drives for parity checks on your important data.

If you really think this is a waste you can set up a ZFS pool as a big disk with no resilience. One failed disk (or even a corrupt bit) and its all gone.

I don't know if FreeNAS supports this foot shooting configuration.

 

[Piggie]

RAIDZ1/2 are not identical to RAID 5/6. They are similar in that they give up 1/2 drives for parity checks on your important data.

If you really think this is a waste you can set up a ZFS pool as a big disk with no resilience. One failed disk (or even a corrupt bit) and its all gone.

I don't know if FreeNAS supports this foot shooting configuration.

I did say my "waste" comment was a joke :)
I'm sure we'd all love not to need having disks that are extra to our needs it we really didn't have to. Unfortunately, it's a fact of life at the moment it seems, till someone can invent something that is guaranteed never to go wrong :)

 

[Adrian]

You could fit a fast read SSD in the ODD bay and use it as a ZFS cache device.
This caches data which has been recently read or is frequently used.
It can fail with no impact on the data.
I use a 64 GB SSD as a cache on my main FreeBSD box.
You can also use a fast USB stick and get some measurable benefit.

For people with lots of SATA ports and money, try using a pair of fast write SSDs as a log device.
This allegedly really speeds up writes.
You need to mirror these because if the log fails your array is toast.

 

[matthewowen01]

You could fit a fast read SSD in the ODD bay and use it as a ZFS cache device.
This caches data which has been recently read or is frequently used.
It can fail with no impact on the data.
I use a 64 GB SSD as a cache on my main FreeBSD box.
You can also use a fast USB stick and get some measurable benefit.

For people with lots of SATA ports and money, try using a pair of fast write SSDs as a log device.
This allegedly really speeds up writes.
You need to mirror these because if the log fails your array is toast.

i really haven't seen any data to show that an SSD provides additional performance for a small environment. the benefit only comes when, the data isn't in memory, it's within the SSD, And you're being hammered so hard by hundreds of clients your disks can't keep up and you're taking a performance hit because of the seek latency. when your working set is larger than your normal ARC and your disks cannot keep up with the additional load. benchmarks will show improvement but an actual impact on real world use won't. if the SSD can get the data in 1ms but the disk can get it in 5ms, can you really tell?

a fast usb stick is going to hurt performance, usb, at Best is 480 mb/s half duplex. that's 60MB/s or 30 in 30 out. and SATA drive will trounce that with the only exception being when you're thrashing your disks.

as a log device yes it will improve performance, but you need to keep them safe and swap them out regularly as SSD's burn out when used this heavily. you can make a Beast of a system by having 2 other hosts, share ram drives via iscsi, which you mirror and use as the zil.
http://opensolaris.org/jive/thread.jspa?messageID=292045&tstart=0
http://www.c0t0d0s0.org/archives/4906-Separated-ZIL-on-ramdisk..html

 

[joeschmuck]

I'd like to chime in here... I agree with Matthew that a USB anything no matter how fast it is will slow you down.

I'm not sure why there was advice to add SSD's to this persons project but my advice is don't, you don't need a zil, not until you have tested out a basic system to see if you need more and even then you need to figure out what will yield better performance.

 

[Adrian]

Using an SSD as a cache does noticeably speed my FreeBSD csup / cvs / build run, and when backing up the same data concurrently to two different destinations. OK, not the sort of thing people are likely to be doing on a Microserver.

Using a USB stick the difference was measurable but not noticeable.

Thanks for the burn-out warning. Another reason for not going the log-device route.

Using dedicated computers as zils sounds like a neat but really expensive solution to making a disk system go really fast.

 

[joeschmuck]

I have two SSD's in my Windows computer, paid $500 (US) for the 256GB 2 months ago and it's FAST! The older one is 128GB and almost 2 years old. I use them because compiling code is so much faster and it's a neat toy (expensive though).

 

[Adrian]

My slightly facetious SSD comment should have been in response to Piggie's post containing:

... A fifth could be fitted into the top drive bay which is really meant for a cd rom unit ...

Apologies for any confusion caused.

I have decided that as I do not really need a NAS, just a target for zfs sends, that I'll set up my MicroServer as a stock FreeBSD 8-STABLE system. I'll then be able to run it under the same FreeBSD version as my other machines and administer it in the same way.

So thanks everybody and goodbye. I am sure that FreeNAS 8.1-RELEASE will be wonderful.

 

[matthewowen01]

I have two SSD's in my Windows computer, paid $500 (US) for the 256GB 2 months ago and it's FAST! The older one is 128GB and almost 2 years old. I use them because compiling code is so much faster and it's a neat toy (expensive though).

Ewwwww Ram disk buddy. I setup a 10 GB ramdisk on my gaming box, i load games in there before i play (little script handles all the loose ends) lets just say there are no load times... it's just there (just benchmarked it, reading 88,000 IOPS and 2.75 GB/s read, writing, 48,000 IOPS, 1.5 GB/s)