SAS Expander Questions

[kom]

Hi, I have been browsing around for a few weeks trying to come up with what to buy, but I don't really know enough to make a decision.

I would like storage for about 20 drives.

Looks like the HP SAS Expander or Chenbro CK23601 would be best, I can only get the Chenbro in Australia, but I can wait for shipping for the HP if its worth it. I found lots of information on the HP one with controllers, and if I decide to wait for shipping I can get any controller for a decent price.

But at the moment I'd like to get the Chenbro from Australia this week with a controller, however I don't really know what ones would suite it, in this case I'd be after the cheapest possible option as nothing is affordable here. I have easy access to Adaptec, Highpoint and Intel products, and can probably get LSI branded, but the price will be high. Are there any options with the minimum to get all drives working?

Also Highpoint has the EJ240, 2 of which can be used with a 2722, this seems good to me but I found virtually zero information on this anywhere, so I'm guessing this isn't a very good option?

Thanks for any help.

 

[mwroobel]

If you are running windows, you will be best served from a performance/reliability standpoint with Hardware RAID6. If you want to do about 20 drives, I would suggest 2 arrays of 11 drives and 1 additional global spare which could be shared between the 2 arrays. A setup like this would require 23 drives and would give you 18 drives worth of available space. Personally, I would suggest an Areca 1882i with an HP Expander, that (plus the drives) would set you up with everything you need. What kind of budget are you working with?

 

[kom]

Thanks for the reply, I don't have a set budget but as cheap as possible would be nice. I have all the drives thankfully.

At the moment the prices for the expander are:
Aus:
HP $600
Chenbro $380

US: (+$50 shipping roughly)
HP: $341
Chenbro: $304

So I can could get the Chenbro without waiting and nearly the same cost, but I have no idea what is a cheap option for a controller card to use with this. I could order the Areca card with the HP expander, but the Areca card is quite expensive for my usage.

 

[kom]

I went ahead and bought a Chenbro CK23601 and some M1015 cards (for it and another machine), haven't set anything up yet. I'm not sure if anyone can help but I'd like my storage set up so that up to 5 people can access data without major slow downs. At the moment all my drives are JBOD and whenever more than 2 users try to access anything the speeds go down to like 2mb/s. My current plan is to use ZFS with a set of around 7-9 drives in RAID6 and some of size 5-6 in RAID5, depending what drives I have around the place. I don't need massive maximum speeds, all I need is to avoid things going at a snail pace with several users. With that in mind does this sound like a realistic set up? And would I see any benefit from using a dual link?

Thanks

 

[Aesma]

In your first post you talk about using windows only, now ZFS.

You never said what HDD you had. For performance in ZFS you need several vdevs.

 

[kom]

Yes, sorry I realised trying to do it with an existing windows system wouldn't be worth it so yesterday I purchased parts for another system. I've been looking at using FreeBSD, so I will try that first. At the moment I only have 6x Samsung HD204UI 2TB, 2x WD WD30EFRX 3TB and 2x Seagate ST2000DM001 2TB. I will buy another 5-6 WD30EFRX. Then either more of the Seagates or just forget them entirely depending on the price of Toshiba 5400rpm drives if they come to Aus. Files are all 10gb and above, I have proper back ups of anything important and this isn't business critical.

As mentioned with my existing set up of just individual drives if several users try to access data on one drive it crawls, I just don't know what would be an ideal setup to remedy this. I can set up several vdevs (which I will have to anyway as I will be using 3 different types of drive) and try spread data appropriately between the 3 but at a given time there may be multiple users on just one and none on the rest. I purchased some cheapish hardware to run this on, from looking at other peoples builds this seems more than enough:

Xeon E3 1230 v2
Intel DBS1200BTSR (Dual 1GB ethernet ports)
G.Skill Ares 16GB (2x8) (Already had, don't need ECC for my purposes I don't think)
IBM M1015
Chenbro CK23601

As you can probably tell this is mostly new to me, but I will try get stuff up and running this weekend and try figure out as much as I can myself. Any advice would be great though.

 

[young_einstein]

I can set up several vdevs (which I will have to anyway as I will be using 3 different types of drive) and try spread data appropriately between the 3 but at a given time there may be multiple users on just one and none on the rest.

I think that you might be getting your concept of vdevs a little bit mixed up there.

You can add as many VDEVs to a pool as you'd like, and ZFS just combines it all into a single consolidated set of storage.

IE - You don't have to worry about spreading data across the different VDEVs yourself, because ZFS handles that completely transparently behind the scenes.

You've got a slightly odd mish-mash of drives that you're working with, but I'd be setting up the 6 x HD204UI in RAIDZ-2, then trying to get my hands on some more WD30EFRX drives to create another 6 drive RAIDZ-2.

If you can't afford another 4 drives right off the bat, you can always use your 2 x Seagate drives to help make up the numbers (meaning that you only need to try and find one extra drive to get things up and running), but it would mean that your 3TB drives would be limited to 2TB capacity, until you're able to upgrade the rest of the disks in that VDEV to 3TB as well.

 

[young_einstein]

Otherwise, if you're not happy about losing 2 disks to redundancy by using RAID-Z2, I'd also consider setting up 5 x HD204UI in RAID-Z, then your remaining 5 disks in another RAID-Z.

That gives you 16TB of usable space right off the bat, without having to worry about buying any extra drives.

Then, once you're able to replace the 3 2TB drives in your second RAID-Z with 3TB disks, your total (usable) space will jump up to 20TB.

 

[kom]

I think that you might be getting your concept of vdevs a little bit mixed up there.

You can add as many VDEVs to a pool as you'd like, and ZFS just combines it all into a single consolidated set of storage.

IE - You don't have to worry about spreading data across the different VDEVs yourself, because ZFS handles that completely transparently behind the scenes.

You've got a slightly odd mish-mash of drives that you're working with, but I'd be setting up the 6 x HD204UI in RAIDZ-2, then trying to get my hands on some more WD30EFRX drives to create another 6 drive RAIDZ-2.

If you can't afford another 4 drives right off the bat, you can always use your 2 x Seagate drives to help make up the numbers (meaning that you only need to try and find one extra drive to get things up and running), but it would mean that your 3TB drives would be limited to 2TB capacity, until you're able to upgrade the rest of the disks in that VDEV to 3TB as well.

Yea I will try to make use of what I can from my existing drives, but I'm definitely going to get more. If I can get the hardware set up this weekend I think I'll get 4 more Seagates to make another RAIDZ2 of 6 drives. I can then get 4 WD30EFRX later for another vdev.

You're right I had my concepts very off I didn't realise a pool striped all the vdev's in it, I'm not sure why I thought it was manual where data went inside a pool, defeats the purpose of it. Thanks.