The iSCSI EMC AX150i is resold by Dell, and refurbished versions are available pretty inexpensively through the Dell Outlet. We just picked up our second AX150i with 12 500gb SATA drives for around $6,000 total, or about $1,000 per raw terabyte. It’s a great deal for lab or development storage, but there are a couple of gotchas that I haven’t found in other reviews.
The AX150’s Drive Pool Setup Limitations
The AX150i stores its operating system on the first four drives (bays 0, 1, 2, 3). Those 4 drives therefore have less available capacity than the other 8 drives in the AX150i. Those drives cannot be used as hot spares, either, because of their specialized roles.
This breaks the AX150’s drives into the following categories:
- Disks 1-4: some space consumed by OS, can’t be hot spares
- Disks 5-11: full amount of free space
- Disk 12: hot spare (could be any disk number, but I’m picking 12 for this example)
If the user tries to create a disk pool, and tries to mix some of disks 1-4 with disks 5-11 (like creating a 6-disk array with disks 1, 2, 3, 4, 5, 6), the AX150 throws out a stern warning. It will allow the configuration, but the warning is pretty ugly.
So if the user can’t mix drives from those 3 groups (OS, empty, hot spare), that basically leaves the following possibilities:
- One pool with disks 1, 2, 3, 4 – can either be raid 5 (roughly 1.5tb capacity) or raid 10 (1tb capacity)
- One pool with disks 5, 6, 7, 8, 9, 10, 11 – an awkward total of 7 disks, meaning raid 5 (3tb capacity) or only use 6 disks in a raid 10 and get 1.5tb capacity plus an extra hot spare
- One hot spare (or two, if disks 5-10 were used as a raid 10)
Total config space for raid 5 is 4.5tb, and for raid 10 is 2.5tb. That space quantity is fine, but the hard-coded setup limitations on which disks can be grouped together are a pain – especially when we’re only dealing with 12 drives.
The AXI150i Has No Load Balancing
The AX150i has two iSCSI ports, and it does support multipathing with the stock Microsoft iSCSI initiator. I’ve successfully set up both of the iSCSI ports on the same switch, set up two network cards on a Windows server with the MS iSCSI initiator, and then pulled various network cables out during I/O activity. Sure enough, the drives fail over without loss of connectivity or data. To me, that’s an astounding bargain at the sub-$10k price point.
However, with one Windows server and one AX150i, I haven’t been able to break the 90mbps bottleneck – meaning, I don’t get more than one network card of throughput. I’ve tried multiple disk pools, tried multiple drives, different drives on different network ports, and I haven’t been able to figure out how to get it to use two full network ports.
This is not a huge problem at this price point – I’m thankful enough that I’ve even got failover in an array this inexpensive. However, consumers need to be aware that two iSCSI ports doesn’t mean two 1gb network cards with 100% saturation.
It’s Not Expandable
Dell/EMC don’t claim this model is expandable, but this needs to be emphasized to the prospective buyer. Shops with two or more AX150’s can’t combine them, and can’t migrate data from one AX150 to another. If there’s a small amount of free space on two AX150’s, it can’t be combined to create a single LUN.
Again, not a big problem at this great price point, but something to be aware of. This feature is available at higher price points from companies like EqualLogic (now owned by Dell) and LeftHand Networks.
And Yet: A Big Winner At This Price Point
Shops that haven’t invested in shared storage yet can get their feet wet with an AX150 without a big capital commitment. I’d recommend it for a shop that isn’t sure whether or not they’ll go with iSCSI or fiber down the road, or if they’re just not sure about shared storage, period. This class of storage is cheaper to get into – and out of – than a LeftHand chassis. An AX150 can be had for under $10k, whereas the LeftHands and EqualLogics run at least twice that much. Granted, they offer twice as many features and much better scalability.
We took the approach that these are for development sandbox use only, never production. Our VMware lab farm is hooked up to an AX150, and so is my SQL Server data warehouse testbed. It’s a testament to their ease of use that I’m always tempted to slap a production array on one just because we’ve got the extra space.
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We also love our Dell AX150i. It was our first SAN experience. We’re looking to add some additional storage to the device. Any idea whether replacement and additional drives must be purchased through Dell, or will an EMC drive from any reseller work?
Can anyone who has used one of these tell me about their install/setup experience?
I picked up a used one from a company that went out of business I can’t get NaviSphere to detect it. It would seem the part I’m missing is the part that says to make sure the network card it is connected to is on the same subnet as the ax150i, but I can’t seem to find any information anywhere on how to find out what that subnet, how to reset the subnet to some factory default or what the factory default subnet might be.
If anyone has any information that might help point me in the right direction I would greatly appreciate it.
Thanks
The process is called uninitializing the array. Here’s instructions:
https://powerlink.emc.com/nsepn/webapps/btg548664833igtcuup4826/public/ax150/en_US/faqs/FAQs/uninit.htm
I have a ax150i with 4 empty slots. I would be interested to know what types of drives I can put in it.
Thanks
You can put SATA drives in there, but you want to either use exactly the same drive types that you’ve already got, or put the new drive types in a separate pool. If you put fast and slow drives in the same pool, you’re not going to get the performance characteristics you want. You’ll also need to get the drive trays from EMC or Ebay.
Have you tried it with off the shelf drives? Dell says you have to use their special drives.
Thanks
I think the drives require special firmware and formatting.
Flare is apparently the OS it runs.
From http://en.community.dell.com/forums/p/19135581/19282112.aspx :
Flare does look for specific information on the drives and if it does not find it, will report the drives as unsupported. If you have the latest flare and it is still reporting that then they are not supported. If they were purchased from Dell, tell them you were sold the wrong drives. if you puchased them somewhere else, you are out of luck.
Has anyone gotten generic drives to work with the trays? Can you get the same SATA drives it contains, flash and format them to the specifications Flare is looking for?
-chris
No, I haven’t, sorry.
Hi Brent Ozar, do you know how to reset the AX150i box to factory default?
I leave the box running more than 10 hours after uninitialize but it doesn’t help. Reboot many times the result still the same:
Navisphere Express
The storage system cannot be managed for the following reason(s):
The software needed to run this application has not fully started. Please wait a few more minutes before opening a browser window.
Sorry, you got me there – I have no idea. You probably want to call EMC for support.
We’ve got an EMC ax150i, an EqualLogic PS50E, and a Dell NAS 745N loaded with the latest free open source version of OpenFiler. The most impressive price/benefit unit we have is the converted 745N. I bought a used 745N for $500, put 4 1TB disks in for an additional $500, and for a total of $1000 I have a (so far) reliable iSCSI target that supports load balanced 1GB ports and high availability configurations using two machines. Simply amazing.
For the Dell version of the Ax150, according to this forum discussion..
http://en.community.dell.com/support-forums/storage/f/3412/p/19135581/19258567.aspx#19258567
if you put in a drive from anywhere else. then it won’t work.
Also if you can please tell me, does “uninitializing the array” delete all the data on the AX150 as well? We have an AX150 and I have to add more drives to the array without loosing the existing data. but the previous network admin has kindly forgotten to document the ip address and password for the unit.
“Also if you can please tell me, does “uninitializing the array” delete all the data on the AX150 as well?”
Did it delete all the data? Any issues changing the IP’s?
Hi at all,
I have the ax150i for test purposes and started some benchmarks with the first 4 bays. I built a Raid5 and also a Raid 1/0 and wonder that I could’t exceed a 50MB/s sequential throughput barrier. Every self made Linux Raid 1/0 is able to saturate GbE with four 7.200rpm HDDs @ Raid 1/0 in sequential benchmarks.
Has anyone archived some becnhmarks for comparsion purposes?
Jimmy – yep, I only got 60-80MB/sec max.