So So Very Slow LAN speed 🤦🏼‍♂️

[rickeames]

I don't know what in the world is going on, but here is the topology:

Drobo hooked up to an iMac wired in on a gigabit switch.
MBP 16" connected wirelessly to router that is hardwired (obviously).

- Open up the drobo connected as a share (afp or smb...same problem) on the MBP.
- Copy a 1.3 GB file from the share to my MBP. Pretty speedy, under 2 mins.
- Copy that same file back from the MBP to the server. 15+ mins.
- Both systems running Catalina

Essentially, any writing TO the server share is a glacier, but reads are fine. For giggles, I also copied TO the internal SSD of the iMac -- same slow speed, so it's not the drive. I'm not sure what to look at in this scenario. What could cause glacial writes to a server from this MBP?

I'm going to run some further tests with another wired machine and a a different laptop, but this is killing any ability to do backups.

 

[hobowankenobi]

Hard to say. The fact that speeds are good one direction seems like it is not a network problem.

If it is all writes to the Drobo...could be something about the Drobo or the drives.

How full is it? If it was very full...and free space is heavily fragmented,it could certainly hurt writes speeds more than reads.

How many drives? Single volume?

Drobos are generally not known for good write speeds, at least with the legacy models. All the RAID overhead is done in software as I recall, and on a pretty low power board (like most low-cost NAS and RAID boxes). But I would still not expect that big a performance hit.

Drobos also allow mixing and matching different drives too. I always wondered how that might hamper performance. Also...if a single drive is struggling or performing poorly, it would hurt the performance of the entire volume. Hard to know outside of getting an error on a failed drive.

You said hooked to the iMac. USB, or TB?

Now that I think about it...I remember a note about the USB C cable being directional or something. Try unmounting the drive and reversing the cable....If it is USB C. Or a different cable if you have one.

 

[2984839]

The USB C cable is a good thing to check. The SATA connections in the Drobo are another thing to look at.