That's the catch for me, most of the data I'd be putting on an unRAID system would be irreplaceable.

 

Then make backups.  RAID helps, but isn't foolproof.  It's best to have at least one of the backups off-site.  That way if there's a flood, fire, whatever, you can still retrieve some of your data.  Also, RAID won't help against things like accidental deletes, if you delete something it's gone (there may be a chance you can recover, but you don't want to take that gamble).

The only thing to worry about is if you have multiple drives with the same capacity from different manufacturers.  Sometimes there are slight differences, so a 1TB drive from Western Digital may be a few megs smaller than one from Maxtor (or vice versa). 

 

Not only different manufacturers, but the same manufacturer, as well.  I'm using multiple Western Digital 1TB (WD10EACS) drives, and they report at two different byte sizes.  Maybe we should start a thread of disk models and byte counts.  I had previously considered getting one of the faster drives (i.e., faster than the WD GP drive) for my parity drive, but not knowing the byte counts of the others, that could have been an expensive purchase that might not have acheived my end goal.

Best estimate is somewhere around 15-20 years before two drives would fail at the "same time" in a 12 drive array.

 

Just to put this out there and rattle some cages.. You cannot always go by this logic.

Although highly logical from a normal user view, in a data center environment this may not always be the situation.

 

Case in point.

If you buy a number of drives from the same vendor at the same time, the chances of loosing two drives in relative short time frame is much more likely then the 15-20 year mark.

 

I'm sorry to say I've seen this happen "many times".

 

Drives in array go bad, we put in an RMA... in a few days while the new drive is on it's way back, the other drive starts having trouble because

A) It was manufactured around the same time.

B) There is now more stress on the drive.

 

In the past 5 years this has happened about 4 times.

Fortunately we have not lost data because after seeing this pattern, I had my partner order drives over a period of time instead of all at once from the same vendor. This way we were sure to get different batches.

 

 

For the normal home user, we buy drives in small batches over a longer period of time.

So I don't think we'll see this situation.

 

But as I've been buying the new 1TB drives, I limit my purchase to only two at a time, and wait a month or so before another expenditure.

 

 

 

 

That's the catch for me, most of the data I'd be putting on an unRAID system would be irreplaceable.

 

Then make backups.  RAID helps, but isn't foolproof.  It's best to have at least one of the backups off-site.  That way if there's a flood, fire, whatever, you can still retrieve some of your data.  Also, RAID won't help against things like accidental deletes, if you delete something it's gone (there may be a chance you can recover, but you don't want to take that gamble).

 

This is one of the reasons I'm migrating to trayless SATA enclosures/mounts.

I can pop drives in and out like floppies. Put some away or off site.

 

I think the unRaid concept is ingenious (take a bow Tom).

I can fail a drive, put it away, pop in a new drive and rebuild it.

after rebuild, keep doing this until I'm comfortable with my data stored.

 

 

Weebotech, are you using the Kingwin trayless units?  I was looking at the 3-in-2 Kingwin units but am wondering about the two smaller fans as opposed to others with one large fan.... 

 

I'm about to purchase a slew of the trayles SATA units.

 

In my case, The Centurion 590, I have the ability to put 4 120mm or 4 140mm fans

 

I'm bouncing between two configs.

 

9 Trayless OPEN SATA units.

Logic is, They are all open, the motherboard has 9 SATA ports, so there will be minimal cards installed.

My goal was minimal extra hardware and fans.

 

I'm also considering 4 of 3-in-2 units. for a total of 12 bays + 1 open trayless sata removable bay for a total of 13.

Logic is, 10 terabytes, 2 drives for raid-1 cache, 1 for parity.

I'm planning to take off the 40mm fans and let the case fans suck air through the drive bays that way.

With this config I'll need a port multiplier.

 

The fans I'm considering are 800rpm/30cfn/120mm or 1000rpm/50cfm/140mm

I figure that should be enough to pull air through the hard drive bays and keep the drives cool.

I may only need two. Then I'll just tape up the extra holes.

I have to see.

 

Right now I'm wrestling with power usage on this 2.66 Core 2 Duo.

I considered the conroe-l which has a TDP of 35 watts, but then the bus speed is diminished.

If I can get CPUFREQ installed and drop the power usage down, I'll move forward.

 

So, back to your question, wondering about the 40mm fans.

I've had 40mm fans on removables for a very long time.

This is for IDE based hard drives. They generally last about 2 years so, then start to make noise.

I detest them, but they have worked in the past.

It's replacing them that is always the pain.

This is why I'm going for the case fan vacuum method.

 

I considered the 4in3 module, but that leaves less opening for 2 of the drives.

Also, by using the 3in2 model I can fit one more drive bay into the case.

 

It will be a few weeks before I know totally.

 

One point I noticed is that the OPEN SATA TRAYLESS units have less of a vent on the front.

The 3in2 modules I've choosen have more openings on the front of the unit which may help.

I'm also considering that the unit is enclosed aluminum which may also act as a heat sink in itself.

After being bolted to the chassis this may help dissipate heat further.

 

 

 

 

(actually unRaid handles 17 drives as of this week, but the 17th drive is used as a cache, not as part of the array)

So this is a new feature? Is this in the beta versions only? Where can I read more about it?

 

Weebotech, are you using the Kingwin trayless units?

What other units are popular?

 

Anyone use Addonics? http://www.addonics.com/products/raid_system/#diskarray

 

I'm about to purchase a slew of the trayles SATA units.

Which ones?

 

2 drives for raid-1 cache

What kind of a performance boost does that yield?

2 drives for raid-1 cache

What kind of a performance boost does that yield?

 

It wouldn't, at least not that noticeable, I doubt that's why he's doing it.  RAID-0 is what gives you a nice boost, RAID-1 is for redundancy (it can be a little faster on reads, but a little slower on writes, but it's not that big of a difference).  The way unRAID is configured, anything written to the cache drive has no protection until it's copied to the array overnight.  If you have the cache drive as RAID-1, then it's protected as soon as the data is written to it.  BTW, this isn't something you can setup via unRAID (the RAID-1 part), unRAID needs to see it as a single drive.  An external eSATA enclosure that holds two drives and supports RAID-1 should do it.

(actually unRaid handles 17 drives as of this week, but the 17th drive is used as a cache, not as part of the array)

So this is a new feature?  Is this in the beta versions only?  Where can I read more about it?

 

This is a new feature as of 4.3-beta4:  http://lime-technology.com/forum/index.php?topic=1731.0

> What other units are popular?

> Anyone use Addonics? http://www.addonics.com/products/raid_system/#diskarray

 

I have two of the addonics, 1 of a re-branded kingwin and 1 of the 3in2 kingwins.

 

The addonics fan has a lil whine to it, and one of them the fan started to go bad already.

I noticed that addonics is not selling the trayless sata units any more either.

 

>> I'm about to purchase a slew of the trayles SATA units.

> Which ones?

 

Still deciding, but will probably go for 3 or 4 of the 3 in 2 units.

I may get a number of the single tray units too.

I'm trying to find the one that suits me the best.

 

A benefit of the addonics is you can use molex or SATA power plugs.

 

>> 2 drives for raid-1 cache

> What kind of a performance boost does that yield?

There is no boost with how I'm doing it.

In fact it's a bit of a penalty.

With software raid-1 the kernel will do alternate reads from each drive to speed things up.

With software raid-1 the os can spin down the drive if unused.

 

I'm planning to use a port multiplier and SIL5744 bridge board to give me a SAFE50 configuration.

50% of the two drives are mirrored

50% of the two drives are concatenated.

 

With two 1TB drives I will have 1TB for Parity. 500GB for RAID-1 cache.

Although I really do not plan to use it for cache. The system is fast enough.

What I plan to do is move some services of my other machines onto this one.

Not sure how far I'll get, so far the services consist of

mySQL server, Centralized syslog host environment, nagios environment, dhcp server, pxe boot server and images, squid cache, caching name servers, etc, etc.

 

I have two of the addonics, 1 of a re-branded kingwin and 1 of the 3in2 kingwins.

Any idea which ones are used in the pre-built MD-1500/LL server?  I can't tell if they are trayless.

If they use screws and bolt to a plate or side bars, they are not the trayless modules.

Also, they only have 1 unit, 3 in 2 unit and 4 in 3 unit trayless modules.

 

From what I saw of the pics, it looks like the AMS or re-branded modules.

However, I don't know for sure as I do not have that unit.

 

Still deciding, but will probably go for 3 or 4 of the 3 in 2 units.

I may get a number of the single tray units too.

I'm trying to find the one that suits me the best.

Are you referring to the trayless Kingwin 3 in 2?

Still deciding, but will probably go for 3 or 4 of the 3 in 2 units.

I may get a number of the single tray units too.

I'm trying to find the one that suits me the best.

Are you referring to the trayless Kingwin 3 in 2?

 

Yes. I like them, but I'll have to see how they perform when I remove the 40mm fans.

 

Yes. I like them, but I'll have to see how they perform when I remove the 40mm fans.

Let us know what you find out....thanks