Best hardware solution for RAIDless storage (20+ drives)

[jemcgarvey]

My question is should I invest in SAS, lots of SATA
controllers, or is there a better solution?

Maybe I'm old fashioned, or just clumsy, but I have broken every RAID setup I have tried, one way or another, and though it is the preferred method, I intend to stick with 1:1 backups. I currently run two rigs with 10TB each and manually mirror all of my backed up BluRays, music, etc. I am running into the limits of mobo and cheap SATA controller connections, and I plan to build a single server rig, probably running linux, to share out the drives, and keep two mirrored banks of drives, but I want to expand far beyond my current needs so I'm not always concerned about adding to it.

I have read that SAS works well for daisy chaining dozens of drives, but is this the best solution for a simple setup like mine?

Thanks

 

[Mercutio]

You can stick a couple Dell Perc5s in a system. That gives you the ability to handle 16 drives for around $200.

I actually do something similar, synchronizing around 19TB of data across two sets of file servers with rsync, but I do keep my data in a software RAID6 with hot spares.

 

[jemcgarvey]

So with those you can use up to 16, but what do you use to expand out to more drives? Can't the interface be expanded to 256 or something? I looked on Newegg for "sas expanders" and found nothing... what exactly are they, or do you have to use external rackmount components?

 

[Mercutio]

So with those you can use up to 16, but what do you use to expand out to more drives? Can't the interface be expanded to 256 or something? I looked on Newegg for "sas expanders" and found nothing... what exactly are they, or do you have to use external rackmount components?

SAS expanders can be internal cards or external boxes. They use a single cable connection from your SAS HBA to add X connections to your SAS bus. There's an internal card from HP that's pretty popular with hobbyists, for example.

Unless you deal with Enterprise storage in your day job, you're probably going to wind up buying your parts from Ebay or Craigslist or the like.

Personally, I'm not a huge fan of having all my eggs in one basket. I don't really WANT to have two dozen drives attached to one system.

 

[jemcgarvey]

For safety reasons right? If they are on separate power circuits, wouldn't that be the same? (I'm talking about a rackmount server case for the pc, with only SAS cables connecting it to the rackmount drive bays)

 

[ddrueding]

There are four things a backup should protect against.

1. Hardware failure
2. Virus infection
3. User Error
4. Site destruction (fire, flood, etc)

Keeping the "backup" on the same machine partially protects against the first. Keeping it on another, adjacent machine that keeps previous versions of all changes protects against the first three.

 

[Mercutio]

For safety reasons right? If they are on separate power circuits, wouldn't that be the same? (I'm talking about a rackmount server case for the pc, with only SAS cables connecting it to the rackmount drive bays)

You're taking lots of risks. Power failure, hardware failure, human error, some kind of security compromise... Moving to multiple systems has down sides in terms of ease of administration and obviously greater costs for hardware, but I think it's worthwhile to gain some redundancy.

Personally I'm hoping to be able to afford an LTO changer by the end of the year. My home systems really do need some real backup.

 

[Handruin]

Another option you can look into is a SAS Expander from HP. There is some discussion about it here that describes the expandability you were looking for with a relatively smaller investment.

 

[MaxBurn]

To it would be useful to know what it will be used for, how many simultaneous users etc.

 

[blakerwry]

You can stick a couple Dell Perc5s in a system. That gives you the ability to handle 16 drives for around $200.

Dell lists 16 as the max because that's all that will fit in their rack/tower chassis. The cards will actually do 32 drives per array and 8 arrays. So you're looking at 256 drives. Obviously, with only two 4x connectors you're using port expanders/backplanes to get to that number and performance will bottleneck (may not be an issue)

If you're only looking at 10TB, then you can do this easily with 2TB SATA drives in a single machine. Check out the T610, 8 drive capacity (either 3.5" or 2.5") for under $1000 (you'd then have to buy your own drives). If you think you'll need more than 8 drives then you'll need to look at either 2.5" drives and/or a bigger chassis or go with an external box - like the MD1000 (32 drive capacity)

Remember, RAID is for availability - If you're looking for a backup then use rsync, WHS, or similar dedicated backup software/scheme.

 

[jemcgarvey]

Yes, I am expecting one or two users at a time (essentially just me), and I use sync software already, for the 10TB I have. I am looking at server type racks, since I don't really want another limit like 20TB or something; I'd like to potentially increase it say up to 10 times the drives in the distant future of course, but my question is really what Hand and blake are discussing... if I start with an SAS controller that only has two mini sas connections, am I still able to expand to the maximum (256?) by simply adding backplanes or more multipliers. It looks like the answer is yes...

 

[ddrueding]

The answer is yes, the capacity can scale. But the bandwidth won't. So long as you maintain your low user count, that shouldn't matter.

 

[Bozo]

I don't think I would worry to much about adding drives in the future. As drive sizes keep increasing, you will need less, not more.
Seagate has a 3TB now.

 

[Chewy509]

Yes, I am expecting one or two users at a time (essentially just me), and I use sync software already, for the 10TB I have. I am looking at server type racks, since I don't really want another limit like 20TB or something; I'd like to potentially increase it say up to 10 times the drives in the distant future of course, but my question is really what Hand and blake are discussing... if I start with an SAS controller that only has two mini sas connections, am I still able to expand to the maximum (256?) by simply adding backplanes or more multipliers. It looks like the answer is yes...

There's heaps of new and 2nd hand rack mountable drive chassis available, but the one that stands out is the Sun X5400 servers. (Nicknamed "Thumper"). They hold 48 3.5 SATA/SAS drives in only 4 RU, giving a raw storage capacity of 96TB. However Chenbro and Supermicro have similar solutions as well, but are limited to approx 16-24 drives depending on either drives.

PS. http://www.oracle.com/us/products/servers-storage/servers/x86/034682.pdf

 

[Bozo]

Maybe something here will work for you.

 

[jemcgarvey]

Sorry I haven't been here a while, I just didn't want to think too much about the joys of a server while I was in a financial crunch.

So I gather the best consumer grade option would be:

HTPC with Supermicro AOC-SASLP-MV8 installed and one or two connecting cables to a case like the NORCO RPC-4224 with the HP SAS Expander and as many drives as I can afford (or need at the time). Even better, have two machines set up like this and sync the files across them for physical security.

From what I read the HP card is a perfect solution for my particular application, though interesting that it is more expensive than the actual controller. Either way, as I am decidedly non-RAID at the moment, between the Areca and the Supermicro listed in the other thread (MaxBurn's), all I can figure is that the Supermicro is a better choice as it is rated better. By the way, it will only be operating under Windows 7 64-bit.

 

[ddrueding]

At this point, I would confirm compatibility with 3TB+ drives before I bought anything. Even if you don't plan on using the drives now, you likely will eventually.

None of my Areca or 3Ware cards work with 3TB WD drives.

 

[LunarMist]

Do any controllers handle 3TB+ and advancing format drives yet or can be updated with firmware?

 

[LunarMist]

Do any controllers handle 3TB+ and advancing format drives yet or can be updated with firmware?

a a

 

[jemcgarvey]

That's a very good point... do you mean any GPT disk or just because it's 3TB?

 

[LunarMist]

Advancing format (4KB clusters) is a major issue with RAID controllers, apparently. 3TB+ is another issue. WD suffers from both.

 

[jemcgarvey]

Just to clarify, I will not be using any RAID, so as long as the hardware supports GPT, I think it's fine. I will look into these specific components though.

 

[Stereodude]

Hardware doesn't have to support GPT or not unless you want to boot from it. That's an OS requirement.

 

[Handruin]

Advancing format (4KB clusters) is a major issue with RAID controllers, apparently. 3TB+ is another issue. WD suffers from both.

I think the Hitachi 3TB drives are still classic 512byte cluster size. I don't know if RAID controllers will recognize them.

 

[jemcgarvey]

I thought it was impossible to address more than 2.1GB or something with 512k...

was I wrong?

 

[mubs]

I think the Hitachi 3TB drives are still classic 512byte cluster size. I don't know if RAID controllers will recognize them.

You mean they're not advancing format?

 

[Handruin]

I thought it was impossible to address more than 2.1GB or something with 512k...

was I wrong?

I'm going by what Hitachi posted in their spec. If it doesn't show, click on the specification link. Maybe they're emulating it also, but don't publish this info.

Sector size (variable, Bytes/sector) 512

 

[jemcgarvey]

Sorry I meant 512 bytes but can't edit the darn post...

 

[Handruin]

You mean they're not advancing format?

They're all about advancing platter counts...format on the other hand...can't say.

 

[Handruin]

Sorry I meant 512 bytes but can't edit the darn post...

No worries, I knew what you meant. Editing of posts is only available for like 5 minutes.

 

[Stereodude]

I thought it was impossible to address more than 2.1GB or something with 512k...

was I wrong?

Not necessarily. There's a variety of things at play here.

1) It is impossible to use a MBR to address more than 2^32 512 byte blocks. This works out to a limitation of 2TB (not 2TiB). This is because the MBR can only support a 32bit LBA.
2) All SATA drives, even the advanced format ones, still appear externally to be drives with 512 byte blocks. This can cause issues with data alignment.
3) GUID Partition Table (GPT) supports 64bit LBA's and has no such 2TB limit.
4) In Microsoft OS land only a computer with a proper EFI implementation (as opposed to a BIOS) can boot from a disk that uses GPT and only with 64-bit OS's newer than Server 2003.
5) Most computers don't have EFI, let alone a proper GPT booting EFI implementation.

A RAID card may have several issues with >2TB drives:
1) Inability to handle drives with a LBA's >32bit
2) Incompatibility with advanced format drives due to data alignment

 

[LunarMist]

You mean they're not advancing format?

No, they are not.

 

[jemcgarvey]

Not to revive a thread that could have died, but I wanted to thank all of you for your advice and give the topic a little closure (also for anyone who followed looking for similar help). I have a thread for my most recent build here:

http://hardforum.com/showthread.php?p=1036585197