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FAQ Feedback - for FAQ for unRAID v6

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1 hour ago, johnnie.black said:

Finally run a scrub, make sure there are no uncorrectable errors and keep working normally, any more issues you'll get a new notification

What scrub arguments do you use for a UD pool?  Thanks

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3 hours ago, DZMM said:

What scrub arguments do you use for a UD pool?  Thanks

btrfs scrub start /mnt/disks/UD_pool_name

to get scrub status during or after is done:

btrfs scrub status /mnt/disks/UD_pool_name

 

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On 6/30/2019 at 11:26 AM, Squid said:

Fix Common Problems is telling me that Write Cache is disabled on a drive.  What do I do?

 

This test has nothing to do with any given unRaid version.  For some reason, sometimes hard drive manufacturers disable write cache on their drives (in particular shucked drives) by default.  This is not a problem per se, but you will see better performance by enabling the write cache on the drive in question.

 

To do this, first make a note of the drive letter which you can get from the Main Tab

 

image.png.110b5e815d1f77f136b1bda537d32553.png

 

Then, from unRaid's terminal enter in the following (changing the sdX accordingly)

 


hdparm -W 1 /dev/sdm

You should get a response similar to this:


/dev/sdm:
 setting drive write-caching to 1 (on)
 write-caching =  1 (on)

If write caching stays disabled, then either the drive is a SAS drive, in which case you will need to utilize the sdparm commands (google is your friend), or the drive may be connected via USB in which case you may not be able to do anything about this.

 

99% of the time, this command will permanently set write caching to be on.  In some rare circumstances, this change is not permanent, and you will need to add the appropriate command to either the "go" file (/config/go on the flash drive), or execute it via the user scripts plugin (with it set to run at first array start only)

 

It should be noted that even with write-caching disabled this is not a big deal.  Only performance will suffer.  No other ill-effects will happen.

 

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

 

Above is what I get when I try: hdparm -W 1 /dev/sde

 

Does not work for me.

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Posted (edited)
3 minutes ago, jpowell8672 said:

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

 

Above is what I get when I try: hdparm -W 1 /dev/sde

 

Does not work for me.

contact the drive manufacturer or ignore the warning from FCP

Edited by Squid

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thx for the help guys .. not sure why my cache got corrupted while trying to create VMs but it did and I needed to recover data.. glad i didn't have to start from scratch

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On 6/30/2019 at 8:26 AM, Squid said:

Fix Common Problems is telling me that Write Cache is disabled on a drive.  What do I do?

 

This test has nothing to do with any given unRaid version.  For some reason, sometimes hard drive manufacturers disable write cache on their drives (in particular shucked drives) by default.  This is not a problem per se, but you will see better performance by enabling the write cache on the drive in question.

 

To do this, first make a note of the drive letter which you can get from the Main Tab

 

image.png.110b5e815d1f77f136b1bda537d32553.png

 

Then, from unRaid's terminal enter in the following (changing the sdX accordingly)

 


hdparm -W 1 /dev/sdm

You should get a response similar to this:


/dev/sdm:
 setting drive write-caching to 1 (on)
 write-caching =  1 (on)

If write caching stays disabled, then either the drive is a SAS drive, in which case you will need to utilize the sdparm commands (google is your friend), or the drive may be connected via USB in which case you may not be able to do anything about this.

 

99% of the time, this command will permanently set write caching to be on.  In some rare circumstances, this change is not permanent, and you will need to add the appropriate command to either the "go" file (/config/go on the flash drive), or execute it via the user scripts plugin (with it set to run at first array start only)

 

It should be noted that even with write-caching disabled this is not a big deal.  Only performance will suffer.  No other ill-effects will happen.

 

NOTE:  If this does not work for you, then you will either need to contact the drive manufacturer as to why or simply ignore the warning from Fix Common Problems

 

Excellent work, this worked perfectly.

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