Author Topic: Changing the disk order  (Read 1548 times)

Offline dremeier

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Changing the disk order
« on: October 17, 2015, 04:47:37 am »
What will happen if I change the disk order?
for exaple:
I´ve 5 disks, 3 as DRU 1 as PPU, these four disk build my fist tRAID. The Raid is online and mounted.
Now I unplug disk 3 with is not in the tRAID. The order of the disk will change.
Does tRAID will just recognize the dike letter or will it recognize the disk-id?

I tried this on a VMware. The result was terrible, no notification of an missing disk even not saying a disk is dropped, nothing.
tRaid was available on the mount point and the data were also available. But if I click verify, I got the error "the disk is missing".
The disk which was fist sdh is now sdg and also bind in the raid array but on the wrong order!
So in VM it it not working, is it working on real machine?

Is it possible to identify the disk by id and bind it to the array instead if just the letter?  (ls -l /dev/disk/by-id)

I hope you see my point?

Offline Brahim

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Re: Changing the disk order
« Reply #1 on: October 17, 2015, 05:47:52 am »
1. You might be confusing yourself. The system does not rely on mount points nor the OS disk assignment. It uses its own stable tracking system.
Now, there is a current bug that has been fixed for the next release whereas you can have disk ID collision if your restore a disk to another and keep both in the system (they end up having the same ID).

2. You need to setup notification and SMART monitoring if you want to be notified of disk failure. Transparent RAID does not fail a disk until it affects parity.
If a disk fails due to parity issues, you will be notified if you have notifications setup.
This leniency allows for re-instating a disk in cases of glitches without having to unnecessarily restore it.
In fact, it is a feature whereas you can even pull out a disk for whatever reason without the array failing or being degraded unless there is an operation that affects parity.

Offline dremeier

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Re: Changing the disk order
« Reply #2 on: October 17, 2015, 08:41:16 am »
Thank Brahim,
2. I setup the notification via email. the test worked!

1. My be I´m confusing a bit myself. But the System must be so clear and easy that I can maintain the system after a year without study the hole flexraid system again. If the System has it own stable tracking system, why does the disk changed from sdh to sdg and allocate the disk wrongly in the array?
Never the less I tried a new traid array with new disks to figure out the ID tracking of flexraid. But in this array i can´t change a disk (fail a disk then swap the disk) see pic. Why?

Thank you so mutch
André

Offline Brahim

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Re: Changing the disk order
« Reply #3 on: October 17, 2015, 10:56:01 am »
Hi Andre,

You will need to enable configuration override to be able to manually fail a disk (Advanced Operations -> Configuration Override -> Enable Configuration Override).
As explained before, you must be having a case of disk collision (two disks having the same ID), a bug which has been fixed for the next release.
There will even be a menu option for existing installation to fix things if affected.


FYI, kudos to you for taking the time to test things out in order to get more comfortable with the system. I really like to see that. ;)

Offline dremeier

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Re: Changing the disk order
« Reply #4 on: October 17, 2015, 12:34:10 pm »
ok thanks, with the 'enable configuration override' I can change a disk or fail the disk!

What do you think when you can release for the bugfix?

now I was able to build a complete new system from the scatch without any failure or hanging, great! I guess I´m ready for my running Live-System with 25TB and 16 Disks!
I have to move a lot of data and have to build a lot of flexible tRAID.

In the case I´ll like FlexRAID Standards™ too, which is comming soon, can I import the existing tRaid or does I have to rebuild? I can´t see the point or different between tRAID and FlexRAID Standards™.

Last question (hopefully):
I´m just playing with the system:
I had 5 DRU´s in tRAID, removed one DRU, now I want to add this disk again but it is not available, why?


 

Offline Brahim

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Re: Changing the disk order
« Reply #5 on: October 17, 2015, 01:02:30 pm »
FlexRAID Standards will indeed support tRAID configurations. So, users on tRAID will be able to migration to Standards by simply re-using their existing configuration database file. The UI will pretty much be the same only with more features.

When you remove a disk RAID Contraction, it is automatically unregistered. So, to add it again to an array, you will have to re-register that disk.

Offline dremeier

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Re: Changing the disk order
« Reply #6 on: October 17, 2015, 01:15:32 pm »
I know it is OT but I don´t know to help by my self, I´m sitting 2 days without break and read a lot about your system.

I removed just disk sdd (8048) from tRAID, the disk is still in the "registered Disk..", I can´t remove it from that list and also not add or use this disk in any other way. Also in "Physical Drives" the disk sdd can´t be registered.


Offline Brahim

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Re: Changing the disk order
« Reply #7 on: October 17, 2015, 01:49:44 pm »
I don't think I follow. That disk is your parity disk. So, what do you mean by you removed it?
It can't be registered because it is already registered and in use.

Offline dremeier

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Re: Changing the disk order
« Reply #8 on: October 18, 2015, 05:04:31 am »
ups sorry, my mistake, not sdd
I removed sdf from the tRAID array.

I´m very confusing now, all the disk numbers are not in the container there should.
My be I´m mixing up something, but it is very imported for me to know which disk in which container.
In the pic you can see that now sdg is in the sdj container and sdf is in the sdi container. By this confusing order and mix i can´t find the correct disk.

please can you have a look again?

Offline Brahim

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Re: Changing the disk order
« Reply #9 on: October 18, 2015, 07:45:16 am »
If you did not remove sdg from the system and it is affected by the disk collision issue I spoke of previously, you will still have issues.
Creating a new config does not resolve the disk collision issue.

Again, if you are keeping replaced disks in the system after restoring them to another disk, you will have disk collisions. The next build will resolve that.
« Last Edit: October 18, 2015, 07:50:44 am by Brahim »