Dell PowerVault is three different product lines sold under one name, and buying the wrong one is the most common storage mistake. MD arrays are direct-attached SAS storage that you plug into one or two servers. ME4 arrays are SAN storage that many hosts share over Fibre Channel, iSCSI or SAS. NX units are NAS file servers that run Windows Storage Server and share files over the network. Pick by how your servers will reach the storage, not by capacity. This guide explains the three families, lists what Dell publishes, and gives a checklist before you pay for a refurbished Dell PowerVault storage array.
| You need | Look at | Why |
|---|---|---|
| More disk space for one or two servers, or a backup target | PowerVault MD (for example MD3420) | Connects straight to the server over 12Gb SAS, no storage network needed |
| Shared storage for VMware or Hyper-V hosts, or a small SAN | PowerVault ME4 (ME4012, ME4024, ME4084) | Dual controllers, Fibre Channel, iSCSI or SAS host ports, many hosts can share it |
| Office file shares, home folders, Active Directory permissions | PowerVault NX | A file server appliance on Windows Storage Server, not a block array |
If the DAS, SAN and NAS terms are new, read our SAN vs NAS guide first, or Serverwale's NAS vs SAN vs DAS comparison and the NAS vs SAN page.
The MD3 family (MD3420, MD3820 and similar) is a shelf of drives with its own RAID controllers, joined to a server by SAS cables. The MD3420 is a 2U array with 24 x 2.5-inch bays and 12Gb SAS connectivity, according to reseller listings of Dell's specification; it supports SAS, near-line SAS and SSD drives, and can be expanded with MD1200 or MD1220 shelves. Sources disagree on the maximum drive count, so ask for the limit of your exact unit and firmware in writing.
Choose MD when one or two PowerEdge servers need a lot of fast disk, for example a database server, a backup repository or a media workstation pool, and you do not want to build a storage network. The trade-off is reach: only the servers cabled to it can use it. Serverwale lists the MD3420 and MD3820 series on its PowerVault page; see also the MD3400 listing in live stock.
Dell's ME4 series has three models: the ME4012 (2U, 12 x 3.5-inch bays), the ME4024 (2U, 24 x 2.5-inch bays) and the ME4084 (5U, 84 drives). Dell's product page and datasheet describe two hot-swappable controllers per array running active-active, with host interface options of 16Gb Fibre Channel, 10Gb iSCSI or 12Gb SAS, and a drive range from 2 up to 336 with expansion enclosures (ME412, ME424 and ME484, all 12Gb SAS). The ME4084 needs both controllers; the two 2U models can run on a single controller.
Choose ME4 when several servers must share the same disks, for example a two- or three-host VMware cluster using shared datastores, or when you want the storage to survive a controller failure. A shared array is also what lets you use features such as moving virtual machines between hosts. Remember that a SAN needs the network side too: iSCSI needs 10GbE switch ports and cabling, Fibre Channel needs HBAs and a switch (see our NIC speed guide). For sizing the hosts around it, read the virtualization host sizing guide. Serverwale lists the ME4012, ME4084 and MD3820 series, and there is an all-brand SAN storage price list.
NX units are PowerEdge-based servers loaded with Windows Storage Server. Dell's support matrix lists the NX3240 (2U, built on a PowerEdge R740xd platform, with 12 front 3.5-inch bays plus a mid-bay), the NX3340 (1U, built on an R640, normally clustered in front of a separate storage array such as a PowerVault ME4) and the NX440 (1U, branch office). The NX430 was an earlier 1U model and Dell's matrix shows it replaced by the NX440. Factory RAID on the data drives is RAID 5 or 6, and the OS drives are mirrored.
Choose NX when the job is file sharing: department folders, home directories, SMB and NFS shares with Active Directory permissions. Do not choose it for VMware datastores that need block storage. Older NX3200 and NX3230 units are common on the refurbished market; Serverwale lists these and the NX3340 on its NAS page. Check which Windows Storage Server version the unit carries and whether the licence is included, because old versions are out of mainstream support.
Rent when the need is temporary, such as a migration, a project, a test of how much capacity you really use, or a DR copy for a few months. Buy when the data is permanent and growing. Serverwale offers both on its NAS, SAN and DAS rental guide and the Dell storage on rental page. For the servers that attach to the array, see Dell server rental and R740 vs DL380, or compare Dell vs HP servers. Serverwale's price index shows how refurbished server prices compare with new.
What is the difference between PowerVault MD, ME4 and NX? MD is direct-attached SAS storage for one or two servers. ME4 is a SAN with dual controllers that many hosts can share over Fibre Channel, iSCSI or SAS. NX is a NAS file server running Windows Storage Server.
Which PowerVault is best for VMware? An ME4 array, usually the ME4024 for flash and SAS drives or the ME4012 for capacity, because several ESXi hosts can share its volumes. Confirm the host interface (Fibre Channel, iSCSI or SAS) matches your hosts and switches.
Can I use a PowerVault MD3420 without a SAN? Yes. It is direct-attached, so you connect it to a server with SAS cables and no storage network. Only the servers cabled to it can use it.
Is the PowerVault NX3340 a standalone NAS? Dell's support matrix describes the NX3340 as a front end that is usually deployed as a cluster in front of separate storage such as a PowerVault ME4. Confirm what is included in the unit you are buying.
Does a refurbished PowerVault array come with both controllers? It should, but you must check. Ask for the controller count, firmware version and host port type in writing before you pay.
Where can I buy or rent a PowerVault in India? Serverwale lists refurbished Dell PowerVault MD, ME4 and NX units to buy or rent, and states a 3-year warranty. Ask for the exact configuration and terms for the unit you choose.
Tell us your data size, users, backup window and budget, and we will suggest a storage setup and quote it. Serverwale · Phone +91-87962-44410 · WhatsApp https://wa.me/918796244410 · Burari, Delhi 110084, India. See enterprise solutions, browse live stock or server AMC plans.
Sources: Serverwale Dell PowerVault page; Dell PowerVault ME4 series product page; Dell PowerVault NX support matrix; reseller listings for the MD3420 (Dell's own sheet was not reachable). Specs vary by configuration; check your exact unit.