Inexpensive 1U iSCSI SAN <£1250 ???

LeaUK · 17th August 2007

Here's my requirement:

<£1250

1U
SATA II 500GB (total), expandable to a min of 4 x SATA II
RAID 5 hardware inc batt
3000 series processor (negotiable) x 2
Redundant PSU
x2 1Gb/s Ethernet
Motherboard: Tyan/Supermicro ??

OS - I've considered running Open-E iSCSI SMB to reduce the OS cost

Any thoughts/pointers most welcome.

Regards
Lea

WFCS · 17th August 2007

Hi,

We have a simple but cheap 1.4(ish) TB iSCSI SAN running with similar specs to what you have posted. The Open-E product works really well and the server has been really stable.

Depending on the amount of use, you could possibly just use a single Dual Core CPU, I think ours just uses a P4 3.2 Dual Core.

Only my thoughts, but it may help a little.

Karl · 18th August 2007

They use memory more than CPU, depending on how hard you're using them and exactly what for - The more memory, the faster it'll be, don't forget that Linux (which is what Open-E is) caches files in to RAM for faster access.

LeaUK · 18th August 2007

It sort of struck me when I considered using the 3000 series that for 4 disks max it was kind of over kill - I take your point.

Paul

Quote:

The Open-E product works really well

Have you tried using it with any virtulization products out of interest? Also, which version of Open-E did you opt for and why? I'm a little confused if this is a hardware product that plugs into a peripheral somehow of software?

One last thing, I have zilch experience with Linux, will that be an issue do you think?

Thanks
Lea

Karl · 18th August 2007

You don't need any Linux experience, as you never have to bring a shell up on it (actually, I'm not sure you can). We've used the iSCSI R1 (Now discontinued) in our testbed, to try all sorts of things out - I even had a Virtual Machine (Inside free VMWare) on my PC, booting Linux from the iSCSI (Not a trivial thing to do, but not rocket science if you know Linux well enough).

We've also got a DSS box running as well, that we use for bits and pieces.

dch · 18th August 2007

As Karl says - on the Open-E you cannot access the OS at all really - you can get shell access via SSH, but it is only to their own interface (the same one you have access to as if you were sat in front of it) Basically you do everything via the web interface. We have quite a few of the Enterprise Open-E dongles around, most of them are the IDE version which I believe are now discontinued, although I believe you can swap them out - I also believe they are discontinuing all but the Enterprise version now as well.

If cost is an issue something else that may be worth looking at is FreeNAS - While I only have this running on a USB stick at home for Music/Pictures/Movies/etc It may be worth looking at.

Cheers,
Sean

andyb28 · 18th August 2007

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LeaUK · 22nd August 2007

Hi All

So the Open-E gear does have a dongle - IDE or USB based. That's what the pictures are!

One guesses the OS boots from either?

Whilst cost is always a driving factor it's no the most important, compatibility, reliability and ease of use (read reduction in hours to manage) are just as, if not more so.

Re FreeNAS. Uhm, like that too.

So all that's needed is a boot USB stick/boot CD with FreeNAS loaded and then use the web interface to configure iSCSI, sounds like a dream.

Only problem I see is one of SPoF. Need a case with twin PSUs...any recommendations?

Off to investigate further...

Big cheers
Lea

LeaUK · 22nd August 2007

Here's my findings on software based iSCSI: (bear in mind my lack of *nix)

Open-E£118
No win license
uses IDE port or USB
Hardware or software RAID

Sanmelody (Lite) £100
need Win license

FreeNAS£0
USB/CD
Software RAID - hardware assumed?

Wasabi Systems£700!
Some type of Flash adaptor?
Hardware and software RAID

Has anyone compared throughput?

Lea

Karl · 22nd August 2007

Open-E needs an internal USB header. Limited to 16Tb of space unless you purchase an extra license.

San Melody Lite is extremely restricted AFAIK and limited in the amount of storage you can create and number of LUNs from memory.

Wasabi Storage Builder - Is apparently a lot better than Open-E if you're creating large volumes and their tech team is supposed to be a lot more comitted to the job (Although that's all 2nd hand info, not used them personally)

SPoF - Unless you have a 2nd box replicating the storage, you'll have a SPoF no matter how many redundant PSUs, Fans, NICs, RAM etc. you throw at it.

LeaUK · 22nd August 2007

Hi Karl

Yeah, there's always going to be SPoFs but for me it's about substantially reducing risk.

SPoFs are:

Data centre
ISP

I plan on running multiple VMs on server nodes which will interface to the iSCSI server. The iSCSi SAN (hosting the VM HDD images) can be backed up to the local server node machines for increased fault tolerance.

OK, so not quite auto failover if the SAN dies, but remotely recoverable.

Considering that all server nodes are autofailover, no SPoF exists here.

Back to the SPoF of the SAN and considering the risk of failure:

1. HDDs - nope RAID 5
2. PSUs - both, unlikely
3. Motherboard - unlikely
4. RAM - unlikely
5. Proc - unlikely

In my opinion the risk has been substantially reduced - unless I've missed something obvious (probably) !!

Comments?
Lea

edit - whoops, seem to have drifted across to my redundancy thread somewhat....

othellotech · 22nd August 2007

>1. HDDs - nope RAID 5

raid card failure will still take it out, depening on the card type so will a disk fail until its replaced and rebuilt anyway.

>2. PSUs - both, unlikely

they're not entirely independant and they'll connect to the mobo through a signgle point. dual psu's are really of only use if they're connected to entirely separate power systems - a brownout on the rack power feed will fry all of the connected psu's

>3. Motherboard - unlikely
>4. RAM - unlikely
>5. Proc - unlikely

it happens, heat/fan/psu issue cause most of the problems

And you missed out
switch
switchport
nic
cat5 cable
etc

In my opinion the risk has been substantially reduced - unless I've missed something obvious (probably) !!

Comments?
Lea

edit - whoops, seem to have drifted across to my redundancy thread somewhat....[/quote]

dch · 22nd August 2007

Quote:

Originally Posted by LeaUK2

FreeNAS£0
USB/CD
Software RAID - hardware assumed?[b]

Hardware RAID is supported, in my home setup it boots from USB and uses 3Ware - Haven't done any perf tests though, it's just for Music/Photo/Videos and has SlimNas installed too - but that is off topic!

Open-E support in my experience is pretty good.

Cheers,
Sean

LeaUK · 22nd August 2007

Quote:

>1. HDDs - nope RAID 5

raid card failure will still take it out, .

Yep, you're correct there

Quote:

a disk fail until its replaced and rebuilt anyway

doesn't RAID 5 protect against one drive failure - i.e. system continues. Trick is to know it's failed and rebuild/replace quick? SNTP traps etc?

Quote:

a brownout on the rack power feed will fry all of the connected psu's

Brownouts outs are voltage dips and will not damage the PSU or equipment subsequently connected. They are part of the test procedure for all equipment place on sale in Europe ;-)

Quote:

>3. Motherboard - unlikely
>4. RAM - unlikely
>5. Proc - unlikely

it happens, heat/fan/psu issue cause most of the problems

all can be detected and responded to fast.

Quote:

And you missed out
switch
switchport
nic
cat5 cable
etc

Yep, grouped under ISP/colo provider .

Never has a patch cable or NIC die though

Lea

fov · 22nd August 2007

Cat5 failure tends to be a right ar$e to diagnose. Only had it a couple of times and it tends to be when you have done something else and moved the server (so the cable has also been disturbed) which makes you question what you have just changed/added.
It also never fails fails, it just causes issues like packet loss, latency, the link going up and down.