AMI StorTrends 2401i

Enterprise storage needs are increasing by up to 40% per year. Considering this fact and also that you want to follow best practices for data retention and backup for your organization, you need to invest in infrastructure that could easily scale up and meet up your future requirements. Therefore, if you are contemplating on the purchase of a storage appliance that could provide you with the flexibility to be used as both IP-SAN and NAS than this AMI storage appliance is a good option. The AMI StorTrends 2401i storage appliance can be deployed by small to mid-sized enterprises or workgroups in large enterprise. It allows organizations to conserve on additional hardware, integration costs and also on valuable rack space by allowing simultaneous IP-SAN and NAS functionality through the same device. It's a 2U rack-mountable storage appliance having 12 bays for SATA and SAS drives. The box which we received was populated with 12 500 GB SATA drives, hence giving up to 6 TB of storage capacity.

Features

The AMI StorTrends merges Ethernet-based Storage Area Network (IP-SAN) and Network attached Storage (NAS) on a single platform to cater to the entire storage management requirements of SMEs. This StorTrends IP-SAN/NAS series appliance from AMI boasts of features like snapshot scheduling, thin and auto provisioning, multiple RAID support, etc. It also supports expandability via JBOD, and therefore can enable organizations to solve their all data storage related pain points with a single StorTrends storage appliance. Thus by using StorTrends 3201j JBODs the organizations can expand their raw storage up to 256 TB.

Data security is of prime importance, and with snapshot capability of StorTrends 2401i, the administrator can review and mount the data snapshot back to recover the lost data quickly. The Auto Provisioning feature allows administrators to allocate certain storage capacity to the users that will grow as the user starts using it, and will not block huge storage capacity in the NAS from the beginning, thus eliminating under-utilization of the storage capacity. The storage appliance is OS agnostic, hence can cater as centralized data storage medium for Windows, Linux or Mac clients across an existing Ethernet network. The IP-SAN provides features like high availability and synchronous replication therefore it could be deployed for mission critical data that requires “always on” availability and reliability.

ManageTrends, which is the web based GUI makes the manageability of the storage appliance easy and provides the administrator with an intuitive interface to discover and manage the StorTrends appliances over the network, so as to configure and monitor their performance. This GUI interface also provides monitoring functionality for storage performance, capacity and storage-related events, and provides a detailed analysis of storage usage, availability of storage servers. The GUI also shows a system health management screen with a picture of the appliance where the problem or error areas are highlighted. This way, an administrator can see if a chassis fan has failed or the internal temperature of the storage appliance has increased, etc.

The setup

As this appliance acts as both IP-SAN and NAS, we configured for both on the device. We set up the device on an isolated Gigabit Ethernet network. Though the device can easily pick up IP address from the DHCP server, for review purposes we used an isolated network. Therefore we assigned the IP address through the console interface of the device. We setup three Windows XP-based machines as clients to this storage appliance. Though the ManageTrends GUI we used the Storage Configuration Wizard to setup the data volues. We created SAN and NAS volumes with a target and a share respectively. The wizard allocated 20% off storage space for snapshot, and we used RAID 5 for maximum data protection. Also, through the interface we scheduled the snapshot to be taken at hourly interval.

Performance Tests on NAS

We used a client machine running Windows XP and having an Intel Core 2 Duo 2.93 GHz CPU with 2 GB RAM to run the Intel's NAS Performance Toolkit (NASPT) benchmark. NASPT is a comprehensive benchmark that emulates the behavior of actual applications and uses a set of real world workload traces gathered from typical digital applications. It is squarely aimed at measuring the performance of the NAS devices. To gauge the performance of the AMI StorTrend's NAS functionality, we ran the benchmark under two scenarios:

• When it was completely initialized.
• When a drive fails and NAS is rebuilding itself.

For the latter test, having configured the NAS with RAID 5, we pulled out one drive from the chassis to create a scenario where a HDD has failed and the NAS has to rebuild the lost data from the crashed HDD.

Besides these two tests, we also created a simple file transfer test of our own, wherein we compiled a 20 GB folder of various files, ISOs, movie files, etc. and copied it from the client to the NAS device and calculated the transfer time on both the scenarios.

Test Results

The NASPT benchmark revealed that the performance of this AMI NAS when compared to AMI StorTrends 3200n (reviewed December'10) is a bit lower. A large single file of 1.15 GB size had a transfer rate of 40.8 MB/s from client to the NAS device, while the StorTrends 3200n, which was just a NAS appliance, had given a throughput of 56.4 MB/s. The table below gives the comparison of this AMI StorTrends 2401i NAS against the StorTrends 3200n NAS appliance.

On comparing the drop in throughput when the NAS was rebuilding itself, we found that the drop in throughput for AMI StorTrends 2401i was not as significant as it was the case with StorTrends 3200n. Thus confirming that the NAS device continues to function even when one HDD fails (under RAID 5 configuration).

For the 20 GB folder transfer test, when the NAS was completely initialized, it took 10 minutes 15 seconds to transfer the folder from client to the NAS device. When the NAS was rebuilding itself, the transfer time increased to 14 minutes 21 seconds.

IP-SAN Performance

As discussed earlier, to setup the SAN functionality was also easy and straightforward. You can create storage pool and allocate data volume to be used as SAN also create the iSCSI target for it. This iSCSI target will be used by the client/user machines to connect to the SAN through iSCSI Initiators. We setup the three Windows XP based machines as clients to the IP-SAN. Since Windows XP doesn't have iSCSI support, we had to install the iSCSI initiator first on the client machines. While configuring the SAN we had created the target, now through iSCSI initiator we connected to the IP-SAN's iSCSI target. To calculate the performance of the SAN, we ran IOMeter as a cluster using Dynamo tool. This allowed us to determine the throughput and maximum IO/second (IOPS) when different payload size is transferred. As the number of IOPS is inversely proportional to the payload, we see that when we increase the payload at specific multiples the IOPS drop but also the transfer rate specifically for the write operations drops significantly and tends to stabilize as the payload size increases up.

This StorTrends 2401i SAN gave a throughput of 113 MB/s for write operation when the payload size was greater than 256 Kb. As the SAN's default block transfer size was 256Kb we found that the throughput is highest when the payload is also of this size. At 256Kb payload the throughput was maximum at 184MB/s. We found that the SAN clocked a whopping 4168 IOPS in doing a sequential write operation for a 32Kb payload. This IOPS count was 3507 for doing read operation for the same payload size.

The following table shows the drop in IOPS as the payload increases, also it shows that the throughput tends to remain constant at higher payload sizes.

Bottomline: At this price point and with features, this is a storage appliance on which one should invest to keep themselves ready for their future storage requirements as well.