#Raid setup on virtualmachine windows

There used to be a document specifically for вЂњMSA 2040 Best Practices for VirtualizationвЂќ, but I canвЂ™t find it at the moment. Also, further in to this youвЂ™ll find some info at the links below on best practices for virtualization on the MSA 2040. On the MSA2040, I would specifically recommend not to touch any of the cache settings.

Posted by Stephen Wagner at 4:27 PMДҐ Responses to вЂњRAID Cache considerations for Storage (VMWare, HyperV, etcвЂ¦) вЂ“ Quick note on performanceвЂќ The battery backed cache allows cached write procedures to be committed to disk on next restart of the storage unit/storage controller thus providing protection. If you do implement cache without backing it with a battery, corruption can occur on the RAID array if there is a power failure, or if the RAID controller freezes. This could give the impression that there are no storage issues when typically troubleshooting these issues (making one believe that itвЂ™s related to the Linux VMs, the ESXi hosts themselves, or some odd networking issue).ДЄgain, I cannot stress enough that you should have a battery backed cache module, or capacitor backed flash module providing cache functions.

#Raid setup on virtualmachine windows

YouвЂ™ll notice that under Windows virtual machines, this issue wonвЂ™t be observed on writes since the Windows VMs typically cache file transfers to RAM, which then write to disk. This allows writes to occur simultaneously to multiple disks, and also dramatically increases observed performance since the ESXi hosts, and virtual machines arenвЂ™t waiting for write operations to commit before proceeding to the next. This allows write operations to be cached and performed on multiple disks at once, sometimes even optimizing the write procedures as they are processed. Please note, that in virtual environments with storage based off RAID arrays, RAID cache is a must (for performance reasons).В Further, Battery backed RAID cache is a must (for protection and data integrity). Another particular behaviour notice was slow uploading speeds to the vSphere client file browser, and slow Physical to Virtual migrations.ДЄfter troubleshooting and exploring the issue with them, it was noticed that cache was not enabled on the RAID array that wasВ providing the storage for the vSphere implementation. Originally it was believed that this was due to networking issues, since the performance issues were only one way (when uploading/writing to storage), and werenвЂ™t experienced with all virtual machines. They were experiencing issues with uploading files, and performing I/O on Linux based virtual machines. I recently had a reader reach out to me for some assistance with an issue they were having with a VMWare implementation.