Hi, i'm currently running a couple of microservers and a larger SM server which i'd like to takeover the job. I've acquired a couple of hba cards and cables i should be ok slotwise. Can i ask what's the recommened (?) course of actions? Can i just lift the drives and plug'em in to the larger server  all at once or is it better to stagger insertion? Anything i should be doing prior to moving them out of the microservers? Currently upgrading all servers to 6.7 to be on the safe side. Only thing i can see is that one of the two microservers discs are still reiserfs formatted, will this be a problem at all. I appreciate that xfs is the way to go but i really just want to rollup to one larger server and then sort things out if possible. PS What's the drive limit on unraid licenses these days?

I assume that you have a license that will handle the total number of drives when they are all plugged into the same server?   In theory it should just be a case of plugging in the new drives to the new server; using Tools->New Config to put yourself in the state of being able to re-assign disks to the array; assign all the drives as you want them to end up; and then start the array to build parity based on the new disk set.   Mixing disk formats is no problem although once you have all the drives in the new array you might want to start migrating the ReiserFS ones to XFS (or BTRFS).  

 

In terms of preparation the important thing to have done will be to have records of all the serial numbers of the disks.    You do not want to accidentally assign a data disk as a parity drive as that would wipe its data.   It is (as always) a good idea to have backups of anything that is critical 'just-in-case'.

Thanks.

Yes, there's only 7 drives in total being added to an existing server of 4 so existing licence should be ok for now.

I've never really understood 'new config', what exactly does it do? It sounds 'destructive', is it at all?

Regarding parity, the existing large server has twin parity (10TB) and as the drives being migrated are a mix of 8TB/6TB then this should be ok.

Bonus is that i regain those microserver parity drives so they can serve to migrate from resier to xfs once all is up and running.

This sort of work scares me though ....

 

17 minutes ago, superloopy1 said:

I've never really understood 'new config', what exactly does it do? It sounds 'destructive', is it at all?

What it does is set the array to an uninitialised state so that you can set up drives as you want them without Unraid complaining about wrong/missing drives.    There is an option to keep current assignments to reduce the amount you then need to type in when making changes.   When you have finished assigning the drives and start the resulting array for the first time Unraid can recognise disks that have been previously used by Unraid and leaves their data intact.   It is at this point that it 'commit's the current set of drives serial numbers going forward.  using the New Config option invalidates any current parity so it then needs rebuilding with the revised set of drives.

 

If any drive comes up with an 'unmountable' file system stop and ask for advice.   Make sure that you do NOT format a drive unless you are happy to lose its contents.

 

The one time you must NOT normally use the New Config option is when you are trying to recover from a failed drive as using this option invalidates parity.    There are times when an expert user might advise using New Config as part of a recovery option but it should not be used casually by the average user unless they understand exactly how Unraid works with disks.

Edited June 2, 20197 yr by itimpi

Thanks, still sounds scary. So, I'm able to just plug in the 4 drives from my 'small' server to the hba card on the larger and power up. Once back up what will I be faced with? How does it identify the new drives, all with data I need to keep, on my large server? Do I then 'new config' with keep existing assignments so as not to lose any existing data??

 

Just approach it one step at a time. I did it quite a while ago so I recommend you to wait for @itimpi to respond in case the "off the top of my head" steps below have any issue.

1. Back up your most critical data.
2. Quickly test that your HBA cards work with Unraid. Usually it's sufficient to just use an existing server and plug the disks to the HBA and boot up to see if Unraid still recognise all the disks automatically. This will help with the not uncommon situation where the HBA truncates the drive ID so Unraid can't recognize the disk order. If there's a problem, stop and ask questions here.
3. Identify the base server (call it S1) where things will be migrated into. Make sure everything is ready there (e.g. disks plugged into HBA, boot up with correct config, maybe even run it for a few days to sort out any teething issues etc.)
4. Now pick the server to be emptied out (call it S2). Plug the disks from S2 to S1, boot up and start array. DO NOT do a New Config yet! Check that all S2 disks show up in S1 as unassigned. Now write down the order of the S1 disks (e.g. the serial numbers as shown on the Main page) and stop array, do a New Config. Add S1 disks back based on the order you written down and then add the S2 disks and start the array backup. Theoretically, it should just work like that.

Tips for step 4. What I did previously was I turned off the server and physically disconnected the parity disk. Then when I do a New Config, I can simply leave the Parity slot empty and not have to worry about accidentally assigning a data disk to Parity slot. Once everything is up and running (except parity), I then connect the parity disk and assign it to the parity slot (no need to do a New Config here; the newly-reconnected disk will be the only possible choice as parity) and start array and the parity build process starts automatically.

 

 

 

Just an update ... i've made a start on moving two of the drives across to my new server but i think i'm running into a power problem., there's not enough sata power cables offa the psu (corsair hx650) which only has two rails x 4 eight in total ad i'm going to max those out. What do you guys do with lots of drives? Can i split and if so how many is a safe number? There ARE a couple of molex rails unused. Is it a better option to use these with an adaptor? I cant seem to find any psu that has a LOT of sata power rails, someone prove me wrong! Ultimately i'll end up with around 20 drives.

22 hours ago, superloopy1 said:

Just an update ... i've made a start on moving two of the drives across to my new server but i think i'm running into a power problem., there's not enough sata power cables offa the psu (corsair hx650) which only has two rails x 4 eight in total ad i'm going to max those out. What do you guys do with lots of drives? Can i split and if so how many is a safe number? There ARE a couple of molex rails unused. Is it a better option to use these with an adaptor? I cant seem to find any psu that has a LOT of sata power rails, someone prove me wrong! Ultimately i'll end up with around 20 drives.

Best DIY, but need some skill. You may ref. below post