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GeneralRe: Silly Documentation Question Pin
charlieg18-Apr-24 17:05
charlieg18-Apr-24 17:05 
GeneralRe: Silly Documentation Question Pin
charlieg18-Apr-24 17:26
charlieg18-Apr-24 17:26 
GeneralRe: Silly Documentation Question Pin
rob tillaart16-Apr-24 20:50
rob tillaart16-Apr-24 20:50 
GeneralRe: Silly Documentation Question Pin
glennPattonWork316-Apr-24 21:54
professionalglennPattonWork316-Apr-24 21:54 
GeneralRe: Silly Documentation Question Pin
Nelson Goncalves Oct202217-Apr-24 2:17
Nelson Goncalves Oct202217-Apr-24 2:17 
GeneralRe: Silly Documentation Question Pin
jochance18-Apr-24 5:58
jochance18-Apr-24 5:58 
GeneralRe: Silly Documentation Question Pin
charlieg18-Apr-24 17:17
charlieg18-Apr-24 17:17 
GeneralWhat sort of performance should I expect? Pin
dandy7216-Apr-24 5:03
dandy7216-Apr-24 5:03 
[tl;dr]: Is RAID5 really causing such a huge performance hit?

I have a system (a Hyper-V VM host) with both eSATA and USB3.0 connectors.

I have a retired set of 8TB drives. I got myself a Mediasonic HFR2-SU3S2 PRORAID 4-drive enclosure, which can use either connector.

I love how trivial this enclosure's RAID setup is. I chose RAID5, so I have a total of 24TB worth of storage. Performance however makes it downright unusable. I could leave my VMs powered down overnight to back them up, but what I'm currently seeing could take days. Backing up a VM while it's running is just not a good idea (I use robocopy) so the VMs have to remain down while backing them up. That's not gonna fly during my workweek.

I made sure that, whether I'm using USB3 or eSATA, the "Better Performance" radio button is selected in Device Manager / Disk drives / [the RAID enclosure] / Properties / Policies.

Write operations hold steady at ~2.6MB/s. Active time is flat at 100%.

Same setup, but using eSATA instead, holds steady at ~5MB/s. Better, but still way below expectations. I'm questioning what my expectations should be.

The OS sees the RAID, not individual drives. On top of that, I use VeraCrypt to encrypt the entire RAID. I understand RAID involves some overhead, especially for Write operations--parity calculations would be done by the enclosure hardware, not my VM host's CPU. OTOH, VeraCrypt also introduces its own overhead, and that would be done by the host's CPU (which holds steady at ~3-4% when copying, so that's hardly the killer).

Before I got the RAID enclosure, I backed up the VMs onto a single external disk over USB3, and there was always plenty of time to do the whole thing overnight. I forget what I got in terms of transfer rate, but I'll be sure to pay attention the next time I do it - surely at least 10x the current performance. That single disk is also encrypted with VeraCrypt, so--unless I'm missing something--the only thing left that can account for the difference in transfer rate is the fact that the target drives are set up in a RAID, as opposed to transferring to a single drive.

My (somewhat rhetorical) question is: Really?

Does my diagnostic make sense? Is the fact that I'm backing up to a RAID the real performance killer? Everything is otherwise the same - both the RAID and my single external drive are connected via USB3, and using VeraCrypt.

Does it make sense at all that RAID5 kills performance to the extent I'm seeing?

What would you expect with a setup like this? I know I'll never get close to USB3's theoretical maximum throughput, but this is insane.

[The RAID isn't indicating any failure, and the last time I've used the drives individually, they were all working fine]
GeneralRe: What sort of performance should I expect? Pin
PIEBALDconsult16-Apr-24 5:35
mvePIEBALDconsult16-Apr-24 5:35 
GeneralRe: What sort of performance should I expect? Pin
dandy7216-Apr-24 5:46
dandy7216-Apr-24 5:46 
GeneralRe: What sort of performance should I expect? Pin
jochance17-Apr-24 8:01
jochance17-Apr-24 8:01 
GeneralRe: What sort of performance should I expect? Pin
k505416-Apr-24 6:04
mvek505416-Apr-24 6:04 
GeneralRe: What sort of performance should I expect? Pin
dandy7216-Apr-24 7:00
dandy7216-Apr-24 7:00 
GeneralRe: What sort of performance should I expect? Pin
k505416-Apr-24 7:10
mvek505416-Apr-24 7:10 
GeneralRe: What sort of performance should I expect? Pin
dandy7216-Apr-24 7:37
dandy7216-Apr-24 7:37 
GeneralRe: What sort of performance should I expect? Pin
theoldfool16-Apr-24 6:54
professionaltheoldfool16-Apr-24 6:54 
GeneralRe: What sort of performance should I expect? Pin
dandy7216-Apr-24 7:09
dandy7216-Apr-24 7:09 
GeneralRe: What sort of performance should I expect? Pin
theoldfool16-Apr-24 7:32
professionaltheoldfool16-Apr-24 7:32 
GeneralRe: What sort of performance should I expect? Pin
dandy7216-Apr-24 7:48
dandy7216-Apr-24 7:48 
AnswerRe: What sort of performance should I expect? Pin
Clumpco16-Apr-24 21:14
Clumpco16-Apr-24 21:14 
GeneralRe: What sort of performance should I expect? Pin
Daniel Pfeffer16-Apr-24 21:56
professionalDaniel Pfeffer16-Apr-24 21:56 
GeneralRe: What sort of performance should I expect? Pin
Daniel Pfeffer16-Apr-24 21:54
professionalDaniel Pfeffer16-Apr-24 21:54 
GeneralRe: What sort of performance should I expect? Pin
dandy7217-Apr-24 7:13
dandy7217-Apr-24 7:13 
GeneralRe: What sort of performance should I expect? Pin
Daniel Pfeffer17-Apr-24 23:27
professionalDaniel Pfeffer17-Apr-24 23:27 
GeneralRe: What sort of performance should I expect? Pin
dandy7219-Apr-24 7:51
dandy7219-Apr-24 7:51 

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