Write Cache is disabled on Dell H200 (IT Mode)

[jonjon1123]

Hi All,

 

I have a Dell R710 with a H200 flashed to IT mode (and flashed to allow it to be put in the dedicated storage slot if that makes a difference...). I have 4 Seagate 6TB Iron Wolf drives (ST6000VN0033) connected to the H200. From what I understand, this setup should allow unRaid to fully manage the drives. What confuses me is when I run FCP it reports that "Write Cache is disabled" is all 4 of those drives. When I run the following command to enable write caching on drive one of the drives (sdd in the below example):

hdparm -W1 /dev/sdd

It returns the below indicating that write cache is still set to off even though I just issued a commend to turn it on.

/dev/sdd:
 setting drive write-caching to 1 (on)
 write-caching =  0 (off)

This is true for any of the 4 drives.

 

So my question is, does write caching even apply to the H200 when flashed to IT mode? If not, I am assuming I can just ignore the warning in FCP. If write caching does apply, how can I get these drives to accept enabling write cache? I thought it might be a problem with the H200 having write caching disabled by default, but all of the guides I have found entail loading up the LSI software and enabling write cache on a logical volume... which I don't have since I am not using any RAID software on the H200 card itself. Since it is flashed to IT mode, I am passing the drives directly through the H200.

 

Obviously I have confused. Can someone straighten me out?

 

Thanks!

 

-Jon-

[JorgeB]

That's a device setting, not a controller setting, it shouldn't make any difference where the device is connected to.

[jonjon1123]

Gotcha. Any thoughts on why my drives won't let me enable write caching?

[JorgeB]

Not really, it happens to some users, sometimes even for the same user with identical model disks, and it works for some and not for others, likely a firmware issue.

[weirdcrap]

Just as anecdotal evidence, I have a bunch of Seagate NAS drives like yours (ST6000VN0041. ST4000VN000. ST2000VN000) on an H200 in IT mode and they all report write caching as enabled without me having to enable anything.

 

As Johnnie said this may be an issue with the firmware on those particular drives as it doesn't affect all of us.

root@VOID:/home/root# hdparm -W /dev/sdr

/dev/sdr:
 write-caching =  1 (on)

root@VOID:/home/root# hdparm -W /dev/sdi

/dev/sdi:
 write-caching =  1 (on)

root@VOID:/home/root# hdparm -W /dev/sdk

/dev/sdk:
 write-caching =  1 (on)

root@VOID:/home/root# hdparm -W /dev/sds

/dev/sds:
 write-caching =  1 (on)

 

Edited December 1, 2019 by weirdcrap

[jonjon1123]

I contacted Seagate support and they said:

Quote

We do not recommend to our customers using our drive in Linux Operating Systems. The reason for this is that we do not have the exact information for you to know how to use the drive properly on your computer. I do not want to misinform you, but this is as far as our capacity goes regarding Linux.

I suggest connect the drive on Windows computer, you should be able to make a diagnosis of the drive using our SeaTools software. This utility will test the drive to check for any failures of the components, and can also attempt to run repairs.

 I guess I could try hooking up the drives to a Windows machine and enabling write caching there.