Our company recently replaced a lot of VNX storage by new Dell EMC Unity all-flash arrays. Since we are/were primarily a VMware hypervisor house, we decided to go ahead and create the new LUNs as VMware VMFS (Block) LUNs/datastores. This however resulted hitting us a weird and unexpected replication limit at 64 sessions.
Back at Storage Field Day 16 in Boston, Zerto presented their VM replication software. It’s a block level, continuous hypervisor based replication, using a journal to log I/O in a VCR-like fashion. This enables you to rewind to any point in time that’s covered in the journal, and recover your VMs to that exact state. Zerto’s plans are a bit grander than “just VM Replication” though… they aim to cover the complete IT Resiliency market.
Recently I’ve been upgrading a vSphere 5.5 environment to vSphere 6.5U1. The vCenter upgrade process is pretty bulletproof by now: the installer is pretty much completely automated. I did run into some issues during the ESXi upgrade, one of which is the fact there were some conflicting VIBs present in the old installations. This would mean the ESXi 6.5U1 upgrade would not start. Time to start hacking in the CLI!
According to Tintri, the rise of server virtualization broke the traditional storage system. Initially we had relatively simple environments where one server talks to a number of LUNs on a storage system. Sometimes we’d have a small cluster of servers accessing those volumes. Still relatively simple.
Fast forward to now: large clusters of hypervisor hosts are the norm, collectively accessing an even larger number of volumes. Each hypervisor in turn hosts a large number or virtual machines. In case of performance problems, how are you ever going to figure out the root cause and which other systems are affected?
A couple of weeks ago StorMagic announced their newest SvSAN 6 release. The basics are still the same: SvSAN takes the internal disks from two hypervisor servers (HyperV or VMware) and turns them into highly available shared storage. Yes, that’s a two server minimum, not three; so this should be a little bit cheaper compared to VMware VSAN and the likes. What’s new in version 6 is the addition of an Advanced edition with SSD and memory-based caching and tiering.