Is there a way to use SATA cables beyond the 1 meter reach of the specs?

[Stonelesscutter]

I'm planning to build a piece of furniture which I will build a computer into. There will likely be at least two compartments, one which will house the motherboard and main components and another which will have lots of space for storage drives. There will be another compartment which sits in between these two compartments but this won't house any computer parts as it will be for other purposes. I've found out that the maximum length for SATA cables is 1 meter, or at least if you go over 1 meter you may expect issues. I don't think this would be sufficient for the concept I have in mind right now. SAS apparently allows for up to 10 meters in length, which would be more than long enough, but then I might require special drives and other materials. This is something I've not looked into yet. I'm wondering though if it's possible to take a PCI port and attach an extender to that, run that between the compartments, so that I could then attach the drives with SATA cables which won't exceed 1 meter.

 

Does this make any sense?

Would I run into issues regarding the length of the PCI extender cable?

Does the PCI extender cable add to the SATA cable length making it pointless as it would still exceed 1 meter?

Could you recommend any parts I could use to accomplish the goal?

 

Also, as for SAS...

Would I need to look for anything special for a motherboard?

Could you recommend any parts I would need for using this connection method?

 

Any other suggestions about things I forgot to consider would also be much appreciated.

 

The idea by the way is to plan for an (unraid) array of drives which might get as large as 20 or 30, if possible. I won't have that many to start with, but I want to take upgradability into account. I know I could use larger drives, but I think I would prefer using smaller capacity drives (say 4 TB) as if I do encounter a drive failure it would be less costly to replace.

[GDRRiley]

SAS controllers can run sata drives just fine.

you'd likely need a SAS card as almost all non server boards don't have a sas connector.

Go with 8tb+ small drives tend to cost more per gb.

If you are putting 20-30 in look at how you plan to control vibrations and mount them all.

[Stonelesscutter]

8 minutes ago, GDRRiley said:

SAS controllers can run sata drives just fine.

you'd likely need a SAS card as almost all non server boards don't have a sas connector.

Go with 8tb+ small drives tend to cost more per gb.

If you are putting 20-30 in look at how you plan to control vibrations and mount them all.

Thanks for your suggestions!

 

So you're saying that if I use a SAS controller I could run SAS cables to SATA drives and I won't have to worry about the 1 meter restriction?

How many drives could I run on such a controller? Would I need other parts to connect as many drives to the controller, or would I need multiple controllers? Are there any restrictions I would have to keep in mind in regard to the type of PCI slot to use?

 

I know smaller drives cost more per GB, but the large capacity drives pose a significant upfront investment. I'm shooting for a medium range where the drives aren't as costly per GB as a 1 TB or 2 TB drive. Since it will be an unraid configuration, it will be fairly easy to pop in an extra 4 TB drive (or a few of them) when the need arises. And since there are now larger capacity drives on the market, such as 12 TB, 14 TB and even 16 TB, I expect that the price of lower capacity drives may drop later on, as the higher capacity drives are becoming more popular. Maybe that'll turn out to be a false expectation, but it's all speculation at this point. If I were for example to go for two 12 TB drives now, I would also need another 12 TB drive for parity, which is a costly affair. If one of those drives fails, I'll have to replace it with another 12 TB drive, which is again costly. But, if for example I go for six 4 TB drives, it would give me the same 24 TB capacity, and I would only need another 4 TB drive for parity. And if one fails, it wouldn't be as expensive to replace. I don't expect the chance of having two drive failures at once to be very high. So for these reasons, I think I would be better off with more lower capacity drives than fewer higher capacity ones. Of course, feel free to point out any errors in my reasoning.

 

As for mounting the drives, right now I'm thinking of a drawer in which I will build a frame in which I can easily slide drives in from the top, so I would be placing them vertically. I will design it in such a way that the drives fit snuggly and that all points at which they make contact with the frame will be covered in rubber to deal with vibrations. I don't think I will even be screwing them into place. At the top, I will clamp them down with a stiff bar (again covered with rubber) which runs along the entire width of the drawer and can be screwed tightly to the frame. This way, the drives would be held tightly by rubber padding on all sides and it should still be easy to take them out and put them in. I've also got a plan for airflow by the way, so I don't expect to have any problems with heat build-up.

[akio123008]

59 minutes ago, Stonelesscutter said:

So you're saying that if I use a SAS controller I could run SAS cables to SATA drives and I won't have to worry about the 1 meter restriction?

I don't know what he meant, but I wouldn't say so. Usually with this kind of stuff the weakest link in the chain is determinitive. What the standard says by the 1m (apparently) is that below 1m, everything definitely works. Above that, it gets blurry and just how well it works depends on many factors, including how lucky you are.

 

Have you considered using iSCSI?

[GDRRiley]

1 hour ago, Stonelesscutter said:

Thanks for your suggestions!

 

So you're saying that if I use a SAS controller I could run SAS cables to SATA drives and I won't have to worry about the 1 meter restriction?

How many drives could I run on such a controller? Would I need other parts to connect as many drives to the controller, or would I need multiple controllers? Are there any restrictions I would have to keep in mind in regard to the type of PCI slot to use?

 

I know smaller drives cost more per GB, but the large capacity drives pose a significant upfront investment. I'm shooting for a medium range where the drives aren't as costly per GB as a 1 TB or 2 TB drive. Since it will be an unraid configuration, it will be fairly easy to pop in an extra 4 TB drive (or a few of them) when the need arises. And since there are now larger capacity drives on the market, such as 12 TB, 14 TB and even 16 TB, I expect that the price of lower capacity drives may drop later on, as the higher capacity drives are becoming more popular. Maybe that'll turn out to be a false expectation, but it's all speculation at this point. If I were for example to go for two 12 TB drives now, I would also need another 12 TB drive for parity, which is a costly affair. If one of those drives fails, I'll have to replace it with another 12 TB drive, which is again costly. But, if for example I go for six 4 TB drives, it would give me the same 24 TB capacity, and I would only need another 4 TB drive for parity. And if one fails, it wouldn't be as expensive to replace. I don't expect the chance of having two drive failures at once to be very high. So for these reasons, I think I would be better off with more lower capacity drives than fewer higher capacity ones. Of course, feel free to point out any errors in my reasoning.

 

As for mounting the drives, right now I'm thinking of a drawer in which I will build a frame in which I can easily slide drives in from the top, so I would be placing them vertically. I will design it in such a way that the drives fit snuggly and that all points at which they make contact with the frame will be covered in rubber to deal with vibrations. I don't think I will even be screwing them into place. At the top, I will clamp them down with a stiff bar (again covered with rubber) which runs along the entire width of the drawer and can be screwed tightly to the frame. This way, the drives would be held tightly by rubber padding on all sides and it should still be easy to take them out and put them in. I've also got a plan for airflow by the way, so I don't expect to have any problems with heat build-up.

you can run sas cables but you'd need to convert sas to sata which there are cables which do it but I don't believe any are set up to do distance.

I found the guide for basically what you are after doing.

smaller drives aren't going to drop any more, they are hitting the minimum cost already which is why we see SMR coming into play.

 

that sounds like the old backblaze style go check them out if you want plans.

[Stonelesscutter]

27 minutes ago, akio123008 said:

I don't know what he meant, but I wouldn't say so. Usually with this kind of stuff the weakest link in the chain is determinitive. What the standard says by the 1m (apparently) is that below 1m, everything definitely works. Above that, it gets blurry and just how well it works depends on many factors, including how lucky you are.

 

Have you considered using iSCSI?

I have never heard of iSCSI before. Would that work in the (unraid) setup I described?

[Stonelesscutter]

So, what about the idea of a PCI extender? I saw Linus use one to connect a graphics card over a distance while doing an in-desk computer build. How long can those be and would that work connecting one of those SAS controllers to the other end so that I can have short runs from there to the drives?