Rearrange my cables? (edit: also reported array position?)

[NLS]

Question is simple and I suspect so is the reply.

Since my server is home-made, it consists of a couple of SAS/SATA controllers that I use both channels of first and one channel of second, but over the years, I have mixed the cables of the disks.

I want to re-arrange cables to be in sequence (1/0/0, 1/0/1... etc.).

It is possible that this will change the mount names (sdc, sdd, sde etc.).

But of course the disks themselves will be identifiable by they model/serial etc.

 

Can I do this and NOT confuse unRAID?

In the end it doesn't bother me much even if I have to rebuild parity, but do I have to?

Is unRAID smart enough?

 

Edited November 24, 2019 by NLS

[Squid]

1 minute ago, NLS said:

Can I do this and NOT confuse unRAID?

Yes

 

1 minute ago, NLS said:

In the end it doesn't bother me much even if I have to rebuild parity, but do I have to?

 

No

1 minute ago, NLS said:

Is unRAID smart enough?

 

Yes

 

All this assumes though that the HBA's are passing through the actual name of the drive as the device and not something specific to them (with HBA's in IR mode will tend to do)

[NLS]

Here are two examples of a reported drives (xxx is serial ending obviously):

ST3000DM001-1CH166_Z1F3Qxxx - 3 TB (sdn)
WDC_WD30EZRX-00SPEB0_WD-WCC4ECCFAxxx - 3 TB (sdm)

...so I think I am ok.

 

Extra questions:

Will drive mount names change? (suspect yes)

Will unRAID actual "disk numbers" change? (suspect no)

 

Extra extra question:
If the actual unRAID reported disk numbers somehow don't follow the physical disk position (after I re-arrange the cables), I guess the only solution then will be to "break" the array and rebuild it again, set share security again etc.?

(I suspect the reply so I probably won't go that drastic)

 

[Squid]

3 minutes ago, NLS said:

Will drive mount names change? (suspect yes)

 

Yes, but they're irrelevant anyways, and there's no guarantee (although it's unlikely) that even if you don't rearrange cabling that they will stay constant from one boot to another

3 minutes ago, NLS said:

Will unRAID actual "disk numbers" change? (suspect no)

 

No

[NLS]

Thanks.

 

 

[NLS]

I moved the cables fine. Unfortunately this surfaced some mix up I have in the physical positions of some disks.

I would like to also set array disk numbers differently to match physical position (changing physical position is hard as they are screwed in)- if possible.

 

From FAQ:
 

Quote

Can I reorder my drives within my array?

Yes you can UNLESS you have dual parity drives. If you have 2 parity drives, you will have to unassign the second parity drive, then rearrange them as desired and restart the array, then stop the array and reassign the second parity drive and rebuild parity on it again.

Warning: Do NOT try to add or remove any drives during this, as that would invalidate parity. And do NOT try this procedure if one or more drives has failed or been removed.

Assuming you only have one parity drive assigned, reassign your drives as desired and start the array. You may have to put a check in the box Parity is already valid.

 

So, is the above valid? Can I stop array, set disks in different order in array (same data disks just differently ordered - keep parity as is) start the array with "parity is valid" and it works?

 

Edited November 24, 2019 by NLS

[JonathanM]

1 hour ago, NLS said:

So, is the above valid? Can I stop array, set disks in different order in array (same data disks just differently ordered - keep parity as is) start the array with "parity is valid" and it works?

Yes, provided you are using the parity slot. That quote is worded a little poorly in my opinion, as it doesn't make the distinction between having a single parity drive in the parity slot, or a single parity drive in the parity 2 slot.

 

There have been cases I've seen where someone end up with a single parity drive in parity 2 and an empty parity slot.

 

Parity 2 is slot assignment sensitive, you can't rearrange slots without rebuilding the parity 2 slot. You also can NOT switch the parity slots, they are not equivalent. So for someone with a single parity drive assigned to parity 2, there is no way to rearrange the current set of drives and keep parity valid.

 

 

[NLS]

Yes I am in parity (#1). So I guess I'll take the plunge... Worse case scenario to rebuild parity I guess.

 

[NLS]

Well... I stopped parity, removed all disks from slots (aways talking about disks in unRAID, not physical movement)...

I left parity as is.

It doesn't start as it reports "too many disks wrong or missing disks".

All disks I re-arranged show up as "wrong".

I am forced to assign them as they were.

 

Any ideas?

Something changed in some version? Some comment from LimeTech on this? (since the wiki entry is also obviously wrong)

 

[bonienl]

You need to do a "New Config" if you want to reposition disks in the GUI.

If you have single parity then you can check "parity is valid" because repositioning does not affect simgle parity (=parity disk #1)

 

Ps. This has always been the way to do, nothing has changed.

 

Ps2. When re-assigning disks, be aware that you need to update any shares which have restricted access to disks (include/exclude disks)

Edited November 24, 2019 by bonienl

[NLS]

Aaah... so I reconfigure it like from scratch but reuse the parity. I don't edit the existing config.

(now to see where I click what)

 

PS2. Good catch. I have very few restrictions, but indeed need to check this.

 

[Squid]

2 hours ago, NLS said:

Something changed in some version? Some comment from LimeTech on this? (since the wiki entry is also obviously wrong)

 

FWIW, you are correct that the wiki is incorrect in that it's missing the step of hitting "New Config".  unRaid is unique in the world in that the forum is so active and knowledgeable that the wiki suffers from not getting updated (ie: it sucks).

 

EDIT: I've added in the step to hit New Config on the wiki (assuming that I was editing the page you were hitting)

Edited November 24, 2019 by Squid

[NLS]

Here is the problem:

http://lime-technology.com/wiki/index.php?title=FAQ

("Can I reorder my drives within my array?")

 

Which entry did you edit in Wiki?

 

[Squid]

Same one.  Of course, due to idiosyncronacies the changes I made didn't show up on your link, but did show up on the one I was using, even though they were identical pages.  😕

 

It was only a quick edit.  Myself I have no overpowering urge to revamp the wiki and fix everything.  Usually I just concentrate on keeping the FAQs in the forum more or less correct

[NLS]

Thanks.

 

[NLS]

The new instructions are much cleaner, thanks.

 

I did the change and system worked as advertised (will also see after next parity check).

 

Irrelevant to unRAID and relevant to underlying Linux and my hardware, there is still a (minor) issue that, although unRAID disk, physical position and cable numbers are aligned, but NOT OS reported position (so they also don't get sd ID in sequence).

Example:

unRAID, physical, cable, hardware ID, OS mount
1, 1, P0/1, 4:0:3:0, sdf
2, 2, P0/2, 4:0:2:0, sde
3, 3, P0/3, 4:0:0:0, sdb (weirdly enough my cache that is 2:0:0:0 got sdc!)
4, 4, P0/4, 4:0:1:0, sdd

It is possible that Chinese break-out cables are not numbered properly (in that case and if it stays like that after reboot, maybe I'll "mix" them to show properly), or OS/hardware polling is irrelevant. Still kind of weird.

 

Edited November 26, 2019 by NLS

[itimpi]

The sdX type numbers are assigned dynamically by Linux as devices initialise.  This means they can even change between boots without any hardware changes.

[NLS]

yes but what about hardware addresses... wrong labeled break-out cables?