How to swap cache drive and replicate exact data..

[Juzzotec]

Hi guys,

 

I have been using my cache drive which is a 120gb corsair SSD. It seems that I need a larger drive and I have a Fujitsu 2.5" 750gb drive which should be large enough.

 

I run transmission, tvheadend, MySQL database of this drive and I'm wondering what is the exact procedure to swap this out without ruining my current setup and moving an exact copy over to the new bigger cache drive.

 

Searched forum and found a topic but it was based on 4.7 and the person wanted to place the old cache drive as a new data disk. The topic emphasised on this portion, I just want to swap and keep the data intact.

 

Help appreciated guys.

 

Justin 

[garycase]

A few ways to do that ... what I'd probably do with only 120GB to potentially copy is:

 

(a)  Boot to safe mode so no plugins are running.

(b)  Don't use the array for anything else -- but copy the entire cache drive to a folder on one of the array drives ["CacheContents" would be a reasonable name  ]

©  Shut down and remove the SSD and replace it with the 750GB drive.

(d)  Boot again in Safe Mode and copy the folder from the array to the cache drive.

(e)  Reboot in your normal configuration.

 

[Juzzotec]

Thanks Gary, don't I have to stop array and unassigned the cache drive? Before I shut down and do I need to rebuild parity at all. Sorry I this is a silly question, I just want to make sure 

 

also how do u boot safe mode?

[itimpi]

also how do u boot safe mode?

That is a relatively new option that is available in the current 5.0 RC16c version.  You do need access to the console to be able to select it (or edit the syslinux.cfg file to make it the default).

[garycase]

Actually, step #1 is upgrade to RC16c.

 

Then you'll have the option of selecting "Safe Mode" from the keyboard during the boot process.  You'll need a keyboard and monitor to do this.

 

The cache has no impact on parity.  I'd leave it assigned, but be sure you do NOTHING that would use it after you boot to safe mode.    Just copy its entire contents to one of the array drives [or if you want you could copy it all to a folder on a connected PC ... this would probably be faster, since there's no parity involved].

 

 

[Juzzotec]

A few ways to do that ... what I'd probably do with only 120GB to potentially copy is:

 

(a)  Boot to safe mode so no plugins are running.

(b)  Don't use the array for anything else -- but copy the entire cache drive to a folder on one of the array drives ["CacheContents" would be a reasonable name  ]

©  Shut down and remove the SSD and replace it with the 750GB drive.

(d)  Boot again in Safe Mode and copy the folder from the array to the cache drive.

(e)  Reboot in your normal configuration.

 

Thanks garycase... 

 

Yep my steps were as follows:

1. Copy all data in my cache to a disk on my array

2. Stop Array and Shutdown

3. Remove old cache drive and install drive

4. Boot unRAID v5.0rc16c and interrupt auto boot

5. Press TAB option and after the command already available I put a space then unraidsafemode [enter]

6. You will know you are in safe mode when your simple features doesnt load or none of your plugins are available in settings

7. If Auto Start Array is on, stop the array and assign your new drive as cache drive

8. Press Start Array now to bring disk online and you will be asked to format unformatted disk

9. Once complete, transfer data you previously stored

10. Stop Array and boot as usual, you should be all systems are Go!

 

Provided this for any future cache disk swappers.

[garycase]

Glad it all worked as planned -- and the extra details on the process may be useful for anyone doing this in the future.

 

[Juzzotec]

Glad it all worked as planned -- and the extra details on the process may be useful for anyone doing this in the future.

 

Exactly! whenever I learn something new, I like to document the exact steps for any future community members in detail and also for mental memory otherwise I would forget. Also, I always google search unraid [space] whatever task I want to achieve, so keywords are important.

 

Thanks for the help 

 

Just a side question, may be related... I dont use user shares because I prefer the traditional view on nas disk array.

 

Does disabling user shares as I have it now, also disable the mover script from cache to array disks? because the option is not available which is great for me

[garycase]

Does disabling user shares as I have it now, also disable the mover script from cache to array disks? because the option is not available which is great for me

 

The answer is I don't know 

... but I suspect it does indeed disable the script, since if you don't have any cached shares, there's no reason to run it.  But I don't use a cache drive, so I don't know the answer for sure.

 

[dmacias]

I had done what you did recently.  The only thing I didn't do was safe mode because the plugins won't start or install anyway since /mnt/cache doesn't exist when you remove the cache drive (although this is a perfect use for safe mode).  I went from a ssd to a 1Tb drive. But went back to ssd.  Partly cause I needed the 1Tb for another computer but also speed and I  added another array drive and moved everything off cache but plugins and thumbnails. I think the cache pool might be interesting when it gets implemented.

 

 

[Juzzotec]

I had done what you did recently.  The only thing I didn't do was safe mode because the plugins won't start or install anyway since /mnt/cache doesn't exist when you remove the cache drive (although this is a perfect use for safe mode).  I went from a ssd to a 1Tb drive. But went back to ssd.  Partly cause I needed the 1Tb for another computer but also speed and I  added another array drive and moved everything off cache but plugins and thumbnails. I think the cache pool might be interesting when it gets implemented.

 

What speed differences did you find going back and forth? I'm guessing speed wont make much difference since my speed transfering from cache to disk has never gone over 30.17mb's a second anyway and any drive can do this. SSD is overkill in my opinion but then again I havent tested this extensively.

 

The reason I changed out my 128gb ssd, because I use transmission to download on cache and its definetely not big enough for bigger torrents.

[dmacias]

Late reply but the speed was more in sabnzb decoding rars and speed of apps esp mysql for xbmc 4 to 7 different clients.  I never worry too much about cache to disk speed since its done by the mover after hours.  Also there is the lower power consumption since my cache drive didn't really spin down.  The SSD was just an extra disk anyway and I don't do more than 50 gigs a day.  The SSD maybe overkill but the access and write speeds are soo much faster.  And for certain application it's very noticeable.  I wouldn't have a laptop without one or two.