I'm currently using 5.0 RC8a, and I had a drive start to misbehave.  I went to remove it, and I really think the process is far more difficult than it should be.  I would love for there to be a "remove drive" button on the array management screen.  Anyway, I won't comment on the difficulty of implementing something like that, as I have no idea, but thought that is a feature that should be there

Assuming a parity drive, there are two different scenarios when a data drive is removed.

 

1) You want to replace it and have it rebuilt from parity calculation.

2) You don't want to replace it and so parity will have to be recalculated and written to the parity drive.

 

Since these are very different operations with very different results, they are handled with different procedures in the user interface.

 

Which of these scenarios did you have trouble with?

 

i believe, the biggest problem ist with the second scenario... unraid only lets you completely remove a disk (not replace), if you hit "new config" and then you need to setup all other disk, too. you need to remember, which was the parity, which was the cache, etc.

if you only remove the disk, unraid wants you replace the disk and tells you, it's currently missing.

(of course, this scenario could cause data loss, since you would have to copy everything to the other disks manually...)

but still, i think there should be a button to remove the drive from the array (with a big warning).

it would not be that hard if you had a cache drive with enough space, but possible without one

 

1.  Pick drive to remove from array

2.  Check cache drive for enough space, if not - ask where to move the data to - also add this drive as a exclude in user shares so it does not get used

3.  Move the data using rsync

4.  Have user verify data was moved correctly to prevent data loss

5.  Modified initconfig - keep everything above moved drive the same, move everything blow the drive up, also invalidate party

6.  remove exclude from user shares added in step 2

7.  Start parity rebuild

 

Now we just need someone smart enough to write the addon

 

Myk

 

 

Assuming a parity drive, there are two different scenarios when a data drive is removed.

 

1) You want to replace it and have it rebuilt from parity calculation.

2) You don't want to replace it and so parity will have to be recalculated and written to the parity drive.

 

Since these are very different operations with very different results, they are handled with different procedures in the user interface.

 

Which of these scenarios did you have trouble with?

 

I was going with option 2.  It wasn't so much troublesome, as it's involved a crap ton of steps, and now I'm having to recalculate parity...and since I have ~15TB of data, it's going to take about a week.

 

The story was that I had a drive generating errors, when I looked into what the errors were, I decided that I need to remove the drive from the array.  I spent some time on the forum here and on the wiki, got some conflicting procedures, but I think I managed to muddle through it.

 

I did screw up, when I rebooted the unRAID server, before i hit the start array button, I hit the button adjacent to it, which cleared out the previous drive positions.  I couldn't remember what drive was the parity drive (as I have 4 3TB drives), so I guessed...

 

I think I guessed poorly, and the new drive that I assigned to parity, hopefully didn't get wiped... I guess I'll find out if I'm missing data before too long.

i believe, the biggest problem ist with the second scenario... unraid only lets you completely remove a disk (not replace), if you hit "new config" and then you need to setup all other disk, too. you need to remember, which was the parity, which was the cache, etc.

if you only remove the disk, unraid wants you replace the disk and tells you, it's currently missing.

(of course, this scenario could cause data loss, since you would have to copy everything to the other disks manually...)

but still, i think there should be a button to remove the drive from the array (with a big warning).

 

Yeah, ..this is the issue I ran into, and I didn't know which drive was my parity drive.  I guessed (and I'm pretty sure I guessed wrong), hopefully I don't end up losing data 

 

EDIT: son of a bitch, looks like I lost ~3TB of data

to find out, which your parity drive is, you would simply put every disk in a disk slot (and none into parity). the one drive, that is shown as unformatted, is your parity drive. note the id, hit new config again and now select the correct drive as parity

 

if you haven't started any format or parity sync, you might be able to get your data back

to find out, which your parity drive is, you would simply put every disk in a disk slot (and none into parity). the one drive, that is shown as unformatted, is your parity drive. note the id, hit new config again and now select the correct drive as parity

 

if you haven't started any format or parity sync, you might be able to get your data back

 

ship has sailed, it's all right, I don't think I lost anything that can't be recovered... still seems somewhat a difficult process for just taking out a drive that is dying :-/

Although you DO have to be cautious (as you've learned a bit too late), removing a drive is really trivial IF you don't care about retaining parity in the process.    i.e. simply note which drive is parity;  which drive is the cache if you have one;  then shut down, remove the drive you want to remove;  and then boot up and reinitialize the array -- being sure you assign the correct cache and parity drives  (the order of the others doesn't matter).

 

As already noted, if you forget, all you have to do is initialize the array without a parity or cache drive -- then check which drives have your data on them (the parity drive will show as unformatted) ... then assign the appropriate parity drive.

 

It would, however, be possible to have a "Remove Drive from Array" button (with, as you noted, a BIG warning about the consequences) that would remove the drive from the array while retaining valid array parity [simple to do -- but time-consuming; as it would have to basically freeze the drive from any subsequent writes; then update array parity to exclude that drive ... which would takes many hours (the same amount of time as the initial parity computations)].

 

Personally, I don't see much use for this feature, however => the only time I can ever imagine removing a drive is if it's failing or failed ... and in that case the best choice is to simply replace the drive.

 

By the way, anytime you change your configuration (and of course with your intiial configuration) it's a good idea to do an Alt-PrtScrn of the browser window while viewing the web interface;  then simply paste that image in Paint and save the result as a JPEG in your documents folder.    Then you'll always know what your drive assignments are 

Although you DO have to be cautious (as you've learned a bit too late), removing a drive is really trivial IF you don't care about retaining parity in the process.    i.e. simply note which drive is parity;  which drive is the cache if you have one;  then shut down, remove the drive you want to remove;  and then boot up and reinitialize the array -- being sure you assign the correct cache and parity drives  (the order of the others doesn't matter).

 

As already noted, if you forget, all you have to do is initialize the array without a parity or cache drive -- then check which drives have your data on them (the parity drive will show as unformatted) ... then assign the appropriate parity drive.

 

It would, however, be possible to have a "Remove Drive from Array" button (with, as you noted, a BIG warning about the consequences) that would remove the drive from the array while retaining valid array parity [simple to do -- but time-consuming; as it would have to basically freeze the drive from any subsequent writes; then update array parity to exclude that drive ... which would takes many hours (the same amount of time as the initial parity computations)].

 

Personally, I don't see much use for this feature, however => the only time I can ever imagine removing a drive is if it's failing or failed ... and in that case the best choice is to simply replace the drive.

 

By the way, anytime you change your configuration (and of course with your intiial configuration) it's a good idea to do an Alt-PrtScrn of the browser window while viewing the web interface;  then simply paste that image in Paint and save the result as a JPEG in your documents folder.    Then you'll always know what your drive assignments are 

 

This entire post should go on the wiki haha.  Yeah, learned most of the above, won't make the same mistake again!

Although you DO have to be cautious (as you've learned a bit too late), removing a drive is really trivial IF you don't care about retaining parity in the process.    i.e. simply note which drive is parity;  which drive is the cache if you have one;  then shut down, remove the drive you want to remove;  and then boot up and reinitialize the array -- being sure you assign the correct cache and parity drives  (the order of the others doesn't matter).

 

As already noted, if you forget, all you have to do is initialize the array without a parity or cache drive -- then check which drives have your data on them (the parity drive will show as unformatted) ... then assign the appropriate parity drive.

 

Expanding on this, perhaps we can have an "identify parity drive" button, as it seems counter intuitive to try and determine which is the unformatted drive by trying to mount them all as regular disk drives, again, all you're trying to do is pull a failing drive out of the pool.

 

 

It would, however, be possible to have a "Remove Drive from Array" button (with, as you noted, a BIG warning about the consequences) that would remove the drive from the array while retaining valid array parity [simple to do -- but time-consuming; as it would have to basically freeze the drive from any subsequent writes; then update array parity to exclude that drive ... which would takes many hours (the same amount of time as the initial parity computations)].

 

Perhaps a little more of a guided procedure on removing a drive w/o preserving parity (and rebuilding it after)? 

 

Personally, I don't see much use for this feature, however => the only time I can ever imagine removing a drive is if it's failing or failed ... and in that case the best choice is to simply replace the drive.

 

If a drive is starting to show signs it will fail, and if the user has enough free space, they may not need to replace the drive necessarily, and they may definitely not want to wait to get a new drive in as an existing drive is failing.  They will just want to pull that sucker out of the array to minimize any damage.

 

By the way, anytime you change your configuration (and of course with your intiial configuration) it's a good idea to do an Alt-PrtScrn of the browser window while viewing the web interface;  then simply paste that image in Paint and save the result as a JPEG in your documents folder.    Then you'll always know what your drive assignments are 

 

Yup, live and learn, ... perhaps next to the button that resets the drive configurations, there could be a "reload previous configuration" or something to that effect?

 

I guess I'm of the mindset here that if unRAID is meant to manage 20+ hard drives of data, we will be seeing drives fail (hence the parity), however handling that drive failure or removing the drive shouldn't be a process that involves non-intuitive steps.  Why do I need to try and mount all my drives as regular disks to determine which is my parity drive?  In hindsight, it makes sense that that would be a good way to identify it, but as someone who may not be as familiar w/ the process, it's not particularly intuitive. 

 

Same with saving drive configurations, while I understand that taking screen-shots works, I really don't think that should be "expected" user behavior. 

 

I guess at the end of the day, since unRAID puts so much effort into keeping data safe in the event of a drive failure, I think that effort should be extended for keeping the data safe during a drive removal, which I suspect most unraid users will have to undergo at least once (after the first time, it won't be an issue, but that first time is where mistakes will happen.

It is kind of about functionality.. If the button would simply:

 

- give a big warning

- remove the drive from the array (so logically, it should remain physically connected

- give a warning about incorrect parity untill parity is recalculated (and put the array in "red" mode by default with three options: 1) recalulate parity with array down, 2) recalculate parity with array up. 3) remove parity alltogether (also removing the parity drive).

 

Option 1 would be somewhat safer since parity calculation will go quicker with no other use on the array.

Option 2 is very quick but gives degraded array performance, a longer parity calc and subseqeuntly somewhat more risk

Option 3 is clear, no parity in future.

 

So it would not do a lot more then you would do by hand currently but guides you through the process..

 

Same way I would also like a "replace drive" function, this would logically remove a drive from the array and point another disk to replace it. The drive that was logically removed would have the same state as a newly added drive.

 

This would make it possible to do headless off-site disk change, no need to touch the system.. Combined with a hot spare this makes the whole lot more maintenainable.