negotiated disk link speed on LSI Megaraid SAS 9285CV/Netapp DS4246 is less than full link speed

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I’ve recently purchased a Netapp DS4246 which I’ve connected to PortB of my MegaRaid 9285C through a single DAS cable to one of the units IOM6 modues. The Raid card lives in a Fedora 40 box.

I have loaded a mix of drives. Some are SAS (8x900GB drives I removed from my DS2246 a few years ago), others are SATA (3x4TB HGST, a 16TB Seagate, and a set of 5x18TB Seagate). Most of the drives I’ve been filling it with will show in MSM as being connected at the full 6Gbps, however I’m noticing that some are negotiating at lower link speeds (a couple 3Gps and a couple more at 1.5GPs).

Clearly this will be disadvantageous for a RAID array… I want fast, and having mixed I/O profiles is going to kill that before it even starts serving requests.

Google searching led me to a 2yr old post that discusses modifying /sys/class/sas_phy/phy-0:x/sas_phy/ however I dont have this on my Linux install. (lets face it, 2yrs is an eternity in Linux land)

I’ve also seen suggestions that I can adjust the PhyInfo parameters via storcli, however storecli just balks when attempting to do so. (though admittedly, I dont think I should need to - they all show as “no limit” - I was only thinking to try and pin it to 6Gbps)

Is there a good/reliable method to ensure all physical drives negotiate their link at their maximum capable speed?

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Are you sure all the drives support 6G? Unless someone has limited the speed in the HBA settings, by default they should link up at the maximum speed supported by both the card and the drive. Previous generations of SAS and SATA were slower than 6G, so wondering if these could be older drives not capable of 6G. The exception might be if you have a poor or not securely connected cable.

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To clarrify, there are a mix of SAS and SATA drives on the disk shelf, with disks of the same make/model within virtual drive groups. All these drives are 6gbps capable (Ie SATA3 or SAS6)

Within those VD groups (not mixing SAS and SATA types), not every disk is linking at their max speed.

I read that hard rebooting the shelf would solve this as the shelf brings up a maximum of 4 drives at a time, however this has not solved the issue. Stranger yet, its not always the same drive that doesn’t connect at top speed.

The LSI raid card has its physical connection set to no speed limit, so nothing should be limited.