I have been using the PowerVault MD1000 in my lab for just over two years now, and I have one important piece of advice for anyone considering it.
Released over a decade ago in 2006, the Dell PowerVault MD1000 is an incredibly simple to use direct attached storage (DAS) array supporting up to 15 SAS or SATA hard disks. While the MD1000 is of course not the most energy efficient system of its type on the market, it can often be found for under $150 (including shipping) on eBay making it great for home labbers and anyone else looking for some serious storage capacity at home. In my MD1000, I have a six 2 TB drive RAID5 array, and a two 2 TB drive RAID1 array. I have plans to make some changes to this over the next year or so, including adding a six 2 TB drive RAID6 array. It should be noted that running the MD1000 with a PERC6/e only allows you to use 2 TB hard disks, which may be a deal breaker for some. I have read that other RAID cards support bigger drives in the MD1000, so do your research.
Jon Kensy did an excellent comparison of running your own backup and storage system to using a cloud system in this article.
The most important piece of advice I have for someone using the MD1000 is to connect both EMMs to your host server. This allows for fail over between the two EMMs. If one goes down, the other will take over immediately, and you don’t even have to configure anything. I love my PowerVault, but I have had issues with both of the EMMs that it came with. The first one started to have issues about a year after I bought it, and the second one is just starting to have issues now. What happens is that the EMM suffers some problem that causes it to lose its connection to the RAID card. That causes whatever applications that utilize the PowerVault’s storage to fail, and the PowerVault to shutdown because it is no longer connected to a host. Once this happens, the only way to bring the system back up is to issue a restart of the host server (can be done remotely), and a restart of the MD1000. (Must be done with the power switches on the back, and this is really not convenient when the system is remote.) The EMMs can be hot swapped, so if you use Dell OMSA to monitor for hardware issues, you can get a notification when one has an error. This way you can run mission critical applications from the PowerVault and not have uptime issues doe to EMM failures.