Exchange environments that I have worked on over the years are never the same. Companies have preference for certain vendors when it comes to storage. This may be Dell, HP when using a SAN or multiple SAN’s, others just have massive storage arrays attached with Fiber channel or iSCSI. I have for a number of years now had Exchange using storage by Nimbus Data. You can find out more on their website here:
https://nimbusdata.com/
As this technology is still relatively new on the market compared to 3par or Dell EMC that have been around for a long time, the speeds on the Nimbus are not bad. I used the JetStress tool against this storage for almost a year, trying different options and because this hardware was new, I did crash it a few times and this lead to new firmware to fix the bugs in it. Once the new firmware was loaded I went through the same JetStress cycle as before until I got to the point where it crashed again and with numerous log uploads we got to a stable set of firmware on the units and we ran the JetStress for longer and it did not crash.
One thing we did pick up was if we did a storage migration, it formatted the disk. Obviously this was a bug in the firmware and was addressed and fixed. Another scenario with the storage we tested, was copy speeds. This is taking a file and copying it to another server that had disks attached to the Nimbus. The bigger files copied quickly whereas smaller files take longer to copy. This also depends on your switches and how they are configured.
This brings me to an important point. With any new storage configuration, you need to ensure that you thoroughly test it. You may think a year is overkill but it is not as we identified a few bugs and working closely with the vendor we could fix the issues easily and then start the cycle again. If this went into production without testing, imagine the downtime we could have encountered and how much data we could have lost if this was not done.
Nimbus uses SSD disks so the speeds are decent. Seeding a 2TB database can complete in a few hours. If you had to compare this to 3Par or Dell EMC, the timing is almost the same but as each environment is different, the speeds may be different for you. As Exchange 2019 has the new feature call metacache MCDB, this makes use of SSD disks and you can allocate this to be used by Exchange Server 2019. We will not be covering the setup of this as it is a lengthy process and out of scope for this article.
Testing mailbox migrations to the Nimbus storage, we pushed the MRS configuration up in Exchange to do more and being too aggressive, we started seeing disk latency errors on the mailbox migrations. This was due to the fact that disks were provisioned thin instead of thick. Once we changed the volumes to thick, we had better results but still hit the disk latency errors so we tuned down the MRS configuration till we found a comfortable setting that worked. Smaller mailboxes finished in a a few minutes and larger mailboxes that were 50GB+ took a few hours which is not bad. Again the speeds are similar to 3Par and EMC.
The next set of testing done on the Nimbus was migrations off the Nimbus to other storage and it was the same as with moves to the storage. The next test we performed was reseeding a mailbox database in production to see how fast it writes to the Nimbus disk. The setup of creating a mount point is the same as with any other storage and we did ensure the disk was thick provisioned and we started to see more slowness. Looking at the Nimbus controllers it seems we had hit a memory issue and this bug was quickly addressed and modifications made and we saw improvement and stability in the reseeding.
I then pushed multiple reseeds to test and there was a speed reduction compared to 3Par and Dell EMC but it stayed consistent and they all finished in a few hours one after the other.
The verdict here is that Nimbus storage is great for Exchange, especially the speeds but if you order any, make sure that it is patched with the latest stable firmware and then JetStress it like I did to ensure you happy with the end result. Also remember, if you are going to be sharing storage with other applications which is not advisable and supported, you will notice a speed reduction and possible slowness with copies.
