Running Fix Common Problems reports "Write Cache is disabled" on all my drives - including my cache drive.  Going to the main screen the cache drive is listed and has the green dot next to it.  I cannot find any place to "turn on" the write cache.  This has worked in the past, but the error started showing up a month or two ago.

 

This drive is hooked up to the eSATA port on the server.

https://forums.unraid.net/topic/80204-write-cache-disabled-on-disk-1/?tab=comments#comment-745016

 

replace /dev/sdk with the appropriate identifier as listed on the Main tab

It turns out I didn't understand the error message.  The Write Cache is disabled on all my disks except the parity drive.  The hdparm command re-enabled the cache, however installing an Unraid update and rebooting the server disabled the write cache on my disks again.  Used hdparm to re-enable it again on the 5 drives.

The command actually should be permanent.  If it reverts after a power-down, then you'll either have to add the commands to the "go" file or via user scripts (start at first power-on)

I have the same problem, I had to add to to my go file. 

 

my usb is sda, the next six are data and parity drives.  I put this line in my go file, seems to work well:

hdparm -W 1 /dev/sd[b,c,d,e,f,g]

I have two drives with write cache disabled. I have tried to enable with: hdparm -W1 /dev/sdb & hdparm -W1 /dev/sdi but I get: /dev/sdb: setting drive write-caching to 1 (on) write-caching =  0 (off) & /dev/sdi: setting drive write-caching to 1 (on) write-caching =  0 (off). Any ideas or suggestions appreciated. Thanks

I had this problem recently. From what I read this often occurs when all spare sectors on the drive have been used to replace bad sectors. The only solution I found for mine was to replace the drive which was still under warranty. You can also just ignore the warning from FCP and leave write caching off.

I bought a purportedly new old stock OEM WD WD4000FYYZ drive about 5 months ago being used as my parity drive and noticed that it has the write cache disabled and I cannot enable it using the hdparm command. I can't see that SMART indicates that it has any reallocated sectors. I'm a bit frustrated.

Both of my drives with write cache disabled that won't enable does not show any reallocated sectors in smart data either.

My smart didn’t show any problems either.  That appears to be the most likely reason for the drive disabling its write caching though.

 

You could try contacting WD tech support if you want. They told me they don’t support OEM drives and referred me to the retailer that I purchased the drive from (you might have better luck). The retailer just sent me an RMA so no telling what the actual reason was for the drive disabling the write caching.

Hi All I just started seeing this in FCP for my HGST HUH728080ALE600 about two months ago on one of my drives there is no errors in SMART at all and my other WD red's and HGST and Seagates are fine (all 8TB drives)

the closest to same model I have working is HGST HUH728080ALE604 (note the 4 instead of 0 on the end)

hdparm -W 1 /dev/sdg

 

/dev/sdg:

 setting drive write-caching to 1 (on)

 write-caching =  0 (off)

wierd thing is disk speed actually shows this disk perform just as good as the other drives in the array in terms of read and write speeds