Turn my SansDigital raid box into unRaid machine? Please brainstorm with me!

[De1taE1even]

Hey everyone, I have an idea, and I wanted to brainstorm it with the smart folks here on the forum.

 

I have a SansDigital TR8m+B 8-bay hot-swappable RAID box just sitting in a closet, so I thought I'd try to retrofit it into an unRaid machine.  There isn't much room in that box, but there is room for a very small motherboard, no larger than about 5"x5".

 

Here's what I was thinking:

Intel Celeron nano-itx motherboard

 

That board has a mini-pcie port that I was going to plug this sata adapter into:

Syba 2-port SATA/pci-e adapter

 

I chose that Syba adapter because it's the only pci-e adapter I could find that supports port-multiplication, which I obviously need to connect the 8 drives.  Plus, it uses the ASM1061 chipset, which is listed on the hardware compatability wiki.

 

Are there any blaring issues with this setup that I have overlooked?

 

Thanks!

[ken-ji]

I'm fairly sure the ASM1061 does not support port multipliers. the specs say so but its actually the slow CBS version when under the windows drivers. under Linux - no go.

 

 

Does the enclosure have internal port multiplier installed? (I don't think so because of the RAID capabilities)

[De1taE1even]

I'm fairly sure the ASM1061 does not support port multipliers. the specs say so but its actually the slow CBS version when under the windows drivers. under Linux - no go.

 

 

Does the enclosure have internal port multiplier installed? (I don't think so because of the RAID capabilities)

 

Well, that'd be a bit disappointing if the card didn't support what it says it does.  I doubt that the enclosure has a port multiplier.  It comes with a raid card which I'm guessing is what handles that.  Honestly, I don't know a ton about port multiplication though.

[WeeboTech]

I would just as soon pick a higher quality itx board that supports a PCIe card with eSATA.

Build it in the lian li Q25B or something similar.  You don't want your parity drive on a port multiplier.

 

With a port multiplier your speed is divided by the amount of drives on the cable.

A 3GB/s link would be divided by 5 yielding 60MB/s at best.

Frankly, I've never received those speeds, more like 20-30MB/s during high activity.

 

You would most likely need to do some sort of round robin so that only 1 drive is accessed at a time on each eSATA cable during a parity check.

 

You can also see about retrofitting the case with SAS/Mini connectors.

In that case you can get full speed out of the drives with an LSI SAS card that has external sas connectors.

 

That will probably be easier then retrofitting a case for a motherboard.

 

Using an ITX case as a host with a LSI external SAS card with cables, you can have at least 15 drives at full speed.

 

I probably would avoid the specialty board at the expense of an external host.

 

You can also go the cheap route and score an HP Micro server used somewhere. 

Add in the LSI SAS card (or go PMP with the ASM1061 card).

Given the right circumstances in auction, you can'possibly' score a whole host for the cost of that specialty motherboard

Add in the cost of a PCIe controller depending on which way you go.

Put parity in the host on the fastest SATA channel.

 

FWIW, I tested the Startech board that has the ASM1061 chipset. It worked for PMP, but not as well as the Silcon image controller.

[gfjardim]

 

You can also see about retrofitting the case with SAS/Mini connectors.

In that case you can get full speed out of the drives with an LSI SAS card that has external sas connectors.

 

That will probably be easier then retrofitting a case for a motherboard.

 

I think it's not possible. Apparently, the port multiplier is embedded into the SATA backplane.

[WeeboTech]

 

You can also see about retrofitting the case with SAS/Mini connectors.

In that case you can get full speed out of the drives with an LSI SAS card that has external sas connectors.

 

That will probably be easier then retrofitting a case for a motherboard.

 

I think it's not possible. Apparently, the port multiplier is embedded into the SATA backplane.

 

I have the smaller one of these units. You have to really open it up to be sure.

 

In my smaller unit there is the SATA backplane, then there is a daughter board that has the eSATA PMP to SATA breakouts to the back plane.

[De1taE1even]

I would just as soon pick a higher quality itx board that supports a PCIe card with eSATA.

Build it in the lian li Q25B or something similar.  You don't want your parity drive on a port multiplier.

 

With a port multiplier your speed is divided by the amount of drives on the cable.

A 3GB/s link would be divided by 5 yielding 60MB/s at best.

Frankly, I've never received those speeds, more like 20-30MB/s during high activity.

 

You would most likely need to do some sort of round robin so that only 1 drive is accessed at a time on each eSATA cable during a parity check.

 

You can also see about retrofitting the case with SAS/Mini connectors.

In that case you can get full speed out of the drives with an LSI SAS card that has external sas connectors.

 

That will probably be easier then retrofitting a case for a motherboard.

 

Using an ITX case as a host with a LSI external SAS card with cables, you can have at least 15 drives at full speed.

 

I probably would avoid the specialty board at the expense of an external host.

 

You can also go the cheap route and score an HP Micro server used somewhere. 

Add in the LSI SAS card (or go PMP with the ASM1061 card).

Given the right circumstances in auction, you can'possibly' score a whole host for the cost of that specialty motherboard

Add in the cost of a PCIe controller depending on which way you go.

Put parity in the host on the fastest SATA channel.

 

FWIW, I tested the Startech board that has the ASM1061 chipset. It worked for PMP, but not as well as the Silcon image controller.

Well, if I can't retrofit the SansDigital, I won't bother.  I already have a killer unRaid setup, so I certainly don't need another unRaid box, it was just something I thought would be a fun project since I had the SansDigital just laying around.  With regard to the parity disk being on the port multiplier, I had thought of that.  My plan was to connect the parity disk to the one native sata port that exists on that motherboard.  Run the parity drive on its own bus, and put all the other disks on the multipliers.

[De1taE1even]

I have the smaller one of these units. You have to really open it up to be sure.

 

In my smaller unit there is the SATA backplane, then there is a daughter board that has the eSATA PMP to SATA breakouts to the back plane.

My unit seems to consist of two backplanes, 1 per 4 drives, each having one sata connected to it. These two cables lead to the 2 eSata ports outside the case.  What I simply lack the knowledge of is port multiplication.  What I thought was that the backplanes were just, for lack of a better term, "splitting" the sata connection into 4.  I thought that the card you connected it to had to know how to handle multiple drives, hence support for port multiplication.  Am I mistaken?  Do those backplanes actually handle the multiplication?  Either way, do you think the Sata card I picked out in the original post would work?

[RobJ]

My brainstorm is to sell it on eBay!  Use the money to enhance your current unRAID server, or put it toward a new one.

[De1taE1even]

My brainstorm is to sell it on eBay!  Use the money to enhance your current unRAID server, or put it toward a new one.

 

Where's the fun in that???  Haha seriously though, I've definitely thought about going that route as well.

[WeeboTech]

I have the smaller one of these units. You have to really open it up to be sure.

 

In my smaller unit there is the SATA backplane, then there is a daughter board that has the eSATA PMP to SATA breakouts to the back plane.

My unit seems to consist of two backplanes, 1 per 4 drives, each having one sata connected to it. These two cables lead to the 2 eSata ports outside the case.  What I simply lack the knowledge of is port multiplication.  What I thought was that the backplanes were just, for lack of a better term, "splitting" the sata connection into 4.  I thought that the card you connected it to had to know how to handle multiple drives, hence support for port multiplication.  Am I mistaken?  Do those backplanes actually handle the multiplication?  Either way, do you think the Sata card I picked out in the original post would work?

 

The Startech ASM 1061 from newegg worked for me.  A silicon image provided a smoother response.

 

With port multipliers, the bandwidth is divided amoung the drives. there comes a diminishing return.

For reading one drive at a time they are great for providing simpler cabling. It's the parity checks that will slow it all down.

 

If the goal is to do it as project because you can, then so be it.

If it's to provide a backup server with some sort of decent usage. The used HP micro server and eSATA PMP card is the way to go.

 

By the time you buy the Mobo and spend the time retrofitting, It could be done at nearly the same cost with a greater benefit.

With an additional cost of a trayless icy dock on top you can have a 2.5" ssd and 3.5" removable.

Great pre-clearing a drive or using a drive like a floppy for backups.  The lil hp microservers make great utility machines.

[De1taE1even]

The Startech ASM 1061 from newegg worked for me.  A silicon image provided a smoother response.

 

With port multipliers, the bandwidth is divided amoung the drives. there comes a diminishing return.

For reading one drive at a time they are great for providing simpler cabling. It's the parity checks that will slow it all down.

 

If the goal is to do it as project because you can, then so be it.

If it's to provide a backup server with some sort of decent usage. The used HP micro server and eSATA PMP card is the way to go.

 

By the time you buy the Mobo and spend the time retrofitting, It could be done at nearly the same cost with a greater benefit.

With an additional cost of a trayless icy dock on top you can have a 2.5" ssd and 3.5" removable.

Great pre-clearing a drive or using a drive like a floppy for backups.  The lil hp microservers make great utility machines.

 

All valid points, and I get where you're coming from.  My goal is a blend of "because I can" and to be "as cheap as possible because I don't really need it". 

 

Your solution would no doubt be a better performing one, but I don't see how I could do it at nearly the same cost.  The cheapest ebay used microserver I could find is well over $300.  That, with the startech card would run me almost triple what I'd be paying for the mobo and sata card (though, if I bought a full fledged machine that had pcie ports, I wouldn't need the startech card because I could just use the card that came with the SansDigital box).

 

Thanks for the input though.  I knew when I asked that a popular opinion would be that it "isn't really worth it".  That's why I love asking.

 

EDIT1: Forgot about buying RAM.  That added cost would take my project to about $160, not $120.  So your solution would still be about twice as much, but not triple.

EDIT2: Actually, EDIT1 is not true because I just remembered I have a few SO-DIMM sticks in a drawer left over from upgrading the RAM in other machines.

[WeeboTech]

EDIT1: Forgot about buying RAM.  That added cost would take my project to about $160, not $120.  So your solution would still be about twice as much, but not triple.

I did qualify my thought with, "Given the right circumstances in auction, you can'possibly' score a whole host for the cost of that specialty motherboard".

 

If you look at completed auctions, there were many that finished in the $100 to $200 range.

Timing is everything. Around major holidays, End of Oct to Dec, etc, etc.

At some point in the last year or so, these were being blown out brand new at $199. (with memory)

At that cost, it's a no brainer in my book.

I wouldn't need the startech card because I could just use the card that came with the SansDigital box).

The Gen 7 HP Microservers accept 1 x1 and 1 x16 card and have space on top for a 5.25 bay. (given the right icy dock bay you can have a 3.5 and a 2.5 drive up there comfortably)

The Gen 8 HP Microservers accept 1 x16 card.  you can retrofit a 2.5" drive inside.

 

I'm going to further qualify my thought with, If you do the celeron micro board and mini pci, it's more effort then it's worth and it's going to perform poorly.  At least with the microserver, it will have a low-level of performance, but above poor and given the right configuration could do pretty nicely.  It's all based on how the drives are configured. If you configure them sequentially on the PMP, performance will suffer. (In any configuration)  In addition if parity is on the cable it will be worse.

 

With the micro server, if you configure 1 internal drive, 1 PMP drive on cable 1, 1 PMP drive on cable 2, round robin like that you can get 12 data drives performing at close to regular SATA speeds during a parity check or generate. Put the smallest drives on the PMP and possibly configure the top bay with the fastest SATA drive for parity and the potential for decent performance is there.

 

My experience with PMP is when multiple drives are read/written on the same cable each drive access divides speed.

For raid-5, it's not so bad as there are small reads to each drive in sequence.

With unRAID it could hamper things with parity on any of those cables.

 

Are there any blaring issues with this setup that I have overlooked?

The performance with PMP and parity on the same cable is going to be very poor.

The day you have a drive failure and try to rebuild you will be wishing you did not do it this way.

What you save in money, will be spent in time.

 

If you can somehow get the parity on it's own SATA channel, you have a chance of this working at a fair level.

If you can somehow route the SATA port to an eSATA port and go that route, it's feasible. Then there is the cost of a powered eSATA bay.

 

This could be useful as a backup server mirroring a primary server drive for drive.

In that case forgoing parity and using it as a mirror server for backups would be a decent usage case.

 

Frankly, I'm not sure the nano itx board is worth it.

[dgaschk]

I have the smaller one of these units. You have to really open it up to be sure.

 

In my smaller unit there is the SATA backplane, then there is a daughter board that has the eSATA PMP to SATA breakouts to the back plane.

My unit seems to consist of two backplanes, 1 per 4 drives, each having one sata connected to it. These two cables lead to the 2 eSata ports outside the case.  What I simply lack the knowledge of is port multiplication.  What I thought was that the backplanes were just, for lack of a better term, "splitting" the sata connection into 4.  I thought that the card you connected it to had to know how to handle multiple drives, hence support for port multiplication.  Am I mistaken?  Do those backplanes actually handle the multiplication?  Either way, do you think the Sata card I picked out in the original post would work?

 

eSATA operates at 3Gbps => 300MBps. Drives operate at over 150MBs but putting 2 drives should give acceptional perfromance. Use of more than 2 drives will result in unacceptable performace during any parity operation. A maximum of 2 of the 4 ports may be used.

 

There are different usage cases where connecting 4 drives makes sense. unRAID is not one of them.

 

 

[De1taE1even]

Thanks Weebo, the input is very appreciated.  If I were to try to use that itx board, I'd definitely use the native sata port for the parity drive.  I wouldn't want the parity drive on the PMP for sure.  And you guessed correctly on application.  I'd only be using this for pure backup purposes, so performance is a distant second to price, so long as it works.  I might even forego unRaid all together for the backup box and just buy a USB 2-bay enclosure for backup, and run a cron to back up what I want, though having parity on by backup box would be nice.  Maybe my project is, in fact, more effort than it's worth.  It just seems like a fun (and tiny) box to be running an 8-bay unraid setup.  Maybe I can get $150 for that SansDigital box and use those funds for the purchase of a Microserver.  I'll keep my eyes out for a good deal.  Thanks again.

[De1taE1even]

eSATA operates at 3Gbps => 300MBps. Drives operate at over 150MBs but putting 2 drives should give acceptional perfromance. Use of more than 2 drives will result in unacceptable performace during any parity operation. A maximum of 2 of the 4 ports may be used.

 

There are different usage cases where connecting 4 drives makes sense. unRAID is not one of them.

 

Yeah I knew the speeds would suffer pretty badly during parity checks.  Helping mediate that would be putting the parity drive on its own dedicated sata bus out from the mobo, so it wouldn't be on the PMP.  When you say unacceptable performance though, do you just mean slow, or do you also mean unreliable?  This would be a box dedicated purely for backup purposes, so if it's just a matter of the parity check taking a really long time, I'm fine with that.  Of course, if it were unreliable, that's a different argument entirely.

[WeeboTech]

I have the smaller one of these units. You have to really open it up to be sure.

 

In my smaller unit there is the SATA backplane, then there is a daughter board that has the eSATA PMP to SATA breakouts to the back plane.

My unit seems to consist of two backplanes, 1 per 4 drives, each having one sata connected to it. These two cables lead to the 2 eSata ports outside the case.  What I simply lack the knowledge of is port multiplication.  What I thought was that the backplanes were just, for lack of a better term, "splitting" the sata connection into 4.  I thought that the card you connected it to had to know how to handle multiple drives, hence support for port multiplication.  Am I mistaken?  Do those backplanes actually handle the multiplication?  Either way, do you think the Sata card I picked out in the original post would work?

 

eSATA operates at 3Gbps => 300MBps. Drives operate at over 150MBs but putting 2 drives should give acceptional perfromance. Use of more than 2 drives will result in unacceptable performace during any parity operation. A maximum of 2 of the 4 ports may be used.

 

There are different usage cases where connecting 4 drives makes sense. unRAID is not one of them.

 

It's not that cut and dry with the ASM 1061, at least during my tests.

It could be better in more recent kernels.

 

In my tests, the driver for ASM 1061 was very blocky. 

When accessing more then one drive on the same cable, it would block the other drive while the buffer was being transferred thus providing really poor performance.

 

The Silicon Image chipsets provided the smoothest multiple drive performance, perhaps due to smaller buffers.

 

Every simultaneous drive accessed would divide simultaneous speed by the amount of drives.

 

1 - 200MB/s

2 - 100MB~90MB/s

3 - 60 MB/s

4 - 30-40Mb/s

 

These were real tests using dd reads in parallel.

You could see that all drives were accessed in sequence, but in decent manner.

 

The ASM1061 would drop 4 drive simultaneous access to 10MB/s.

In my test case, You could see that only 1 drive was accessed at a time block ing access to other drives, while the first was being read.

 

As mentioned round robin access of the drives could provide decent performance given the right controller, hardware and drive spread.

[dgaschk]

 

1 - 200MB/s

2 - 100MB~90MB/s

3 - 60 MB/s

4 - 30-40Mb/s

 

 

parity check times (4T):

 

1 - 5.6 hrs

2 - 11.2 hrs

3 - 18.52 hrs

4 - 31.75 hrs

 

At what point does recovery time become impractical?

[WeeboTech]

Thanks Weebo, the input is very appreciated.  If I were to try to use that itx board, I'd definitely use the native sata port for the parity drive.  I wouldn't want the parity drive on the PMP for sure.  And you guessed correctly on application.  I'd only be using this for pure backup purposes, so performance is a distant second to price, so long as it works.  I might even forego unRaid all together for the backup box and just buy a USB 2-bay enclosure for backup, and run a cron to back up what I want, though having parity on by backup box would be nice.  Maybe my project is, in fact, more effort than it's worth.  It just seems like a fun (and tiny) box to be running an 8-bay unraid setup.  Maybe I can get $150 for that SansDigital box and use those funds for the purchase of a Microserver.  I'll keep my eyes out for a good deal.  Thanks again.

 

Wow I forgot to add, the HP Microserver can support PMP with the eSATA and the internal SATA.

The motherboard has to be flashed with 'the bay's bios, but from what I remember, it worked.

You would need a SATA to ESATA low profile cable adapter ~$15 or so.

However I would probably just reuse the sans digital card.

So you might be able to use the Sansdigital directly on the HP microserver with minimal extra parts.

 

In addition, if need be, with the two PCI slots, you could use two SIL3132 controllers and have decent performance.

 

Set up an eBay follow for the HP microserver, and see where that brings you.  It'll be a lot less headaches and can I/what if?

[De1taE1even]

So, following the advice given on this thread, I decided to build a new, inexpensive unRaid box for backup purposes.  I had almost decided to buy a used Microserver on eBay, but then I found the wonderful world of inexpensive AsRock mini-itx embedded boards.  Great little boards from what I see and read.  These are the products I ordered:

 

Case ($99): Norco ITX-S4

Mobo ($76): ASRock Q1900-ITX

RAM ($0): 4GB (2GBx2) left over from my MacBook Pro upgrade

PSU ($45): Enhance ENP-7025B Bronze Certified

Drives (4x$139.99): Toshiba 5TB PH3500U-1I72

 

So, not counting the drives, the box build was only $220, which was as cheap as the cheapest eBay Microcenter I could find, and it's a fair bit more powerful as well.  The Norco case only supports 4x3.5 drives, versus the Microserver supports 5x3.5, but I was ok with that.  I posted the SansDigital TR8M on eBay, hopefully I can get it sold and recoup the majority of the build (not including drives of course).

 

Again, thanks for all the suggestions.  Once everything arrives at my doorstep, I'll post a build thread with lots of pictures.  15TB of parity protected storage in a case the size of a toaster for $800?  I'm definitely ok with that. 

[WeeboTech]

Sweet build!

[De1taE1even]

Sweet build!

 

Thanks!  Glad you didn't find anything blatantly wrong with the equipment I picked.  I actually just finished building it, fired it up, and unraid loaded up without a hitch.  I can't do much with it yet because my drives won't be here until next week, but I'm just happy the mobo, ram, and psu all seem to be holding hands and singing nursery rhymes so far.

 

1 note: The single 80mm fan in that Norco case could challenge the dB level of a jet engine.  Imma have to do something about that for sure.  Replace it, install a fan controller, or both.

[De1taE1even]

The box is tiny!

 

 

[WeeboTech]

I'm interested in the performance of the CPU and network.

[De1taE1even]

I'm interested in the performance of the CPU and network.

 

Sure thing, once the system is up and running I'll post a new build thread and notify this thread as well.  Thanks again for the suggestions.