Affordable storage for the SME, part one

Conclusion so far

This was our second attempt (the first attempt can be seen here: Promise VTRAK j300s) at professional storage benchmarking. We want to remind our readers that the objective was not to compare the Intel SSR212MC2 and the Promise VTRAK E310f directly: the target market is quite different, with only a moderate amount of overlap. The main reason that we reviewed them together is that they are the representatives of affordable SAN storage arrays.

The Promise VTRAK E310f is a very attractive alternative to the expensive FC SANs of the big storage vendors. It targets medium sized enterprises, which will like the excellent storage capacity scalability via FC switches and JBODs. Promise keeps the total price of a small SAN lower thanks to the fact that you can choose which FC switch, HBAs, and hard drives you want to buy. The counterargument is of course that having only one vendor to blame for problems is easier, but incompatibility/interoperability problems are easy to avoid if you follow Promise's certification documents and guidelines. Promise's support might not be as luxurious as the big OEMs, which offer next business day on site support, but the support is free.

According to Promise you get 24/7 support (by phone only) which covers all Promise subsystems (M-Class, E-Class and J-Class). Email support is available five days a week (Monday - Friday). Support representatives can help on all subsystem related issues and/or questions and can also process RMAs (including advance replacements). Support is worldwide.

So where is the catch? Promise is relatively new to the SCSI/SAS/SAN world. That means that their products lack some of the more advanced features that the well-established players provide. One of the very handy ones is the ability to make snapshots - backups without any interruption of service. More advanced failover capabilities are limited to the Windows world. Promise has still some way to go before it can be an alternative to the big players for every storage buyer, but it will certainly attract some of the price conscious buyers.

The Intel SSR212MC2 naturally appeals to techies like us. At a very low price you can get a NAS, an iSCSI SAN, and a "normal" server all in one. The caveat is that you need to know what you are doing and need to be capable of installing a Linux iSCSI target for example. Without the proper knowledge, the price advantage will evaporate as you try to configure the system. It is also impossible to get the Microsoft target separately (it is only sold to OEMs), so you must have some Linux knowledge if you want to do it yourself. The alternative Windows iSCSI target (StarWind) we tried so far did not convince us, and the free MySAN iSCSI target is very limited.

That doesn't mean that this storage server is only suited for storage DIYers. At a slightly higher price, you can get this storage server completely ready to deploy with the iSCSI target configured and more. In that case, it is just a matter of checking how the reseller will support you, and you need a lot less (storage) knowledge to configure and troubleshoot. You can get this server with both Microsoft's iSCSI target as with user friendly (and quick to setup) Linux based iSCSI targets such as Open-E.

Promise VTRAK E310f Advantages

• Offers excellent all around performance...
• ... even with RAID 6!
• Attractive price for the storage rack...
• ... low price when you start building the complete SAN
• You are the one who decides which drives and switches you want to use
• Excellent Capacity scalability (thanks to JBODs) with little hassle
• Easy to use and rich web based management interface
• Low cost but 24/7 Support

Disadvantages

• No multipath HA drivers for Linux yet
• Not suited for SMEs without any storage knowledge - you will want (expensive) onsite support in that case
• e610f (3U) probably has a better performance/capacity/price ratio

Intel SSR212MC2 advantages

• Very flexible: Can combine a NAS and iSCSI
• Very flexible part 2: Can combine a server and a storage server into one server
• Very low price, especially if you build it yourself
• You can get a fully loaded OEM version from various resellers - slightly more expensive but less knowledge required
• Support will depend on the reseller, which can be good news

Disadvantages

• Support could also be bad - support will depend on the reseller you chose
• Supports 32 drives at most (limited JBOD expansion)
• RAID 6? Slightly older IOP processor...
• Performance depends a lot on the chosen iSCSI target and configuration

Next!

So is iSCSI really an alternative to fiber channel? What about CPU load, network load, and TCP/IP offloading? We also need to explain some of the weird performance issues we've encountered. However, as this article is getting too long already, we decided to do more in depth testing for our next article.