cache drive issue and a question about my array

[RJGamer1002]

hello, I'm having an issue with my cache drive. and I have no idea why it doing this. first thing I notice was that the cache drive was spin down( it rear for it to spin down or I just never see it spin down). and SMB was not working until I spin the drive back up again manually. then I notice the Fix Common Problems plugin was showing an error saying unable to write to cache and I check cache drive log and there some error messages(check pic). any idea what this mean?

also, mover will not move any files

for the question about the Array. i have 3 disk drives and 2 party drive and 1 cache drive(1tb) and both party drives are 8tb and the disk drive are 8tb, 4tb, 2tb.
but i notice that the array is saying it has a total size of 8tb when it was doing a Parity-Check. any idea why it would saying that? i thought it would make the backup bigger, im i wrong?

[JorgeB]

Please post the diagnostics.

[RJGamer1002]

13 hours ago, JorgeB said:

Please post the diagnostics.

here you go

tower-diagnostics-20221204-1911.zip

[JorgeB]

On 12/3/2022 at 9:54 PM, RJGamer1002 said:

but i notice that the array is saying it has a total size of 8tb when it was doing a Parity-Check. any idea why it would saying that?

That's correct it's the parity size.

 

As for the cache drive, SMART looks OK but it's an old drive, swap cables/slot with a different disk, if issues follow the disk best to replace it.

[RJGamer1002]

6 hours ago, JorgeB said:

That's correct it's the parity size.

i would have thought it would be 16tb( or 14tb).

 

6 hours ago, JorgeB said:

As for the cache drive, SMART looks OK but it's an old drive, swap cables/slot with a different disk, if issues follow the disk best to replace it.

yea i got it used when i first got the server. i'm not going to be home for about 2 weeks. is there something i could try to do? like stop the array and start it back up? or reboot the server? 

i forgot to ask but for the plugin Fix Common Problems it also saying that docker appdata location is not a cache-only share and i should change it to that. but when i did it started to fill my cache drive to 100% full.(this was a few months ago when i did this). but what i want is to only use the cache drive when i transfer files to via SMB and just allow the docker and vm to use the main drives to store data. is that possible?

[JorgeB]

20 minutes ago, RJGamer1002 said:

is there something i could try to do? like stop the array and start it back up? or reboot the server? 

You can try rebooting, but the issue will likely reoccur.

 

21 minutes ago, RJGamer1002 said:

but what i want is to only use the cache drive when i transfer files to via SMB and just allow the docker and vm to use the main drives to store data. is that possible?

Yes.

 

[RJGamer1002]

ok, but maybe it will work until i replace it🤔.(i will give it a try)

 

 

what setting should i set it to then?

[JorgeB]

set cache=yes, run the mover then set to cache=no.

[RJGamer1002]

1 minute ago, JorgeB said:

set cache=yes, run the mover then set to cache=no.

ok i will try that. thanks for the help!

i will update what happen and mark as solved if i don't need anymore help.

[itimpi]

37 minutes ago, RJGamer1002 said:

i would have thought it would be 16tb( or 14tb).

When checking/building parity all drives are read or written in parallel, and all drives have every sector on them accessed, so it is the size of the largest drive that is relevant in terms of elapsed time.

[RJGamer1002]

so, update: the cache drive is running again and is reading and writing again with no error so far. i started running the mover(it working so far). 
 

1 hour ago, itimpi said:

When checking/building parity all drives are read or written in parallel, and all drives have every sector on them accessed, so it is the size of the largest drive that is relevant in terms of elapsed time.

ah that make sense! will one of the 8tb parity drive stop being in parallel when i go past the 8tb mark for storage? and will it be used to store a backup? or do i have to do something manually? i'm at 7.70tb out of 14tb of used storage right now.
 

1 hour ago, JorgeB said:

set cache=yes, run the mover then set to cache=no.

ok i started to do this and the mover almost got everything moved but there a few mb of data that it can't move. how do i move files? or should I somehow delete the file? it's in appdata and it's for docker but all my docker are off right now.

Edited December 5, 2022 by RJGamer1002
adding a question

[itimpi]

4 hours ago, RJGamer1002 said:

ah that make sense! will one of the 8tb parity drive stop being in parallel when i go past the 8tb mark for storage? and will it be used to store a backup? or do i have to do something manually? i'm at 7.70tb out of 14tb of used storage right now.

Parity has no concept of data (i.e. it does not understand file systems).   It simply works at the raw sector level to try and ensure every sector has the correct bit pattern.   When you have 2 parity drives then different calculations are used to work out the bit patterns they should store.   The amount of data on the array is irrelevant to this process.

[RJGamer1002]

1 hour ago, itimpi said:

Parity has no concept of data (i.e. it does not understand file systems).   It simply works at the raw sector level to try and ensure every sector has the correct bit pattern.   When you have 2 parity drives then different calculations are used to work out the bit patterns they should store.   The amount of data on the array is irrelevant to this process.

i think I'm misunderstanding what a parity drive is. i was thinking the parity drive has a copy of the array drives.

[ChatNoir]

5 hours ago, RJGamer1002 said:

i was thinking the parity drive has a copy of the array drives.

It is not : https://wiki.unraid.net/Manual/Overview#Parity-Protected_Array

[RJGamer1002]

8 hours ago, ChatNoir said:

It is not : https://wiki.unraid.net/Manual/Overview#Parity-Protected_Array

yea i realized that now. lol

so i do have one more question about the cache drive. is it possible to set it up to just be used when im uploading file to the server and not to store data from application that are running on the array. like when i change the share like appdata. almost instantly the cacha drive start to have data moved to it from one of the dockers(i set it to just "yes"). i just want the data that i upload to the server to be stored to the cache and then the mover will move my data to the array. is that possible? 

[itimpi]

1 hour ago, RJGamer1002 said:

just want the data that i upload to the server to be stored to the cache and then the mover will move my data to the array. is that possible? 

That will be the behaviour you get if you are downloading to a share which has the Use Cache=Yes setting.

[RJGamer1002]

Well I think rebooting it fix the cache drive because it has not showed an error since rebooting. But I will replace the drive once I get a chance.