Multi-Drive Upgrade Question

[TODDLT]

I am about to do a multi-drive upgrade / swap and considering whether or not to do two at a time.

 

1st I'm upgrading my parity from 3TB to 6TB, so that is two drives.

2nd I'm upgrading one of my data drives from 3TB to 6 TB.

3rd I'm using the 3TB data and one of the 3TB parity drives to replace 2 - 7 or 8 yr old 2TB data drives in the array.

 

So that is 5 drives being replaced.  If I do them one at a time, its 5 - 9-10 hour swaps.

The question is would you undertake any of those 2 at a time still having 7 / 8 yr old drives in the array?  

The 2nd question is, If I was replacing 2 drives, and a 3rd died, could I put the old 2 drives (that were being replaced) back in place and rebuild the 3rd now dead drive? 

 

[ashman70]

AFAIK, you can't do more than one at a time, or you will destroy your array. Since you only have one parity drive, you can only replace one data drive at a time.

 

My advice, do the parity drive first and then the rest the way you have planned. Do not attempt to do more than one drive at a time.

[TODDLT]

2 hours ago, ashman70 said:

AFAIK, you can't do more than one at a time, or you will destroy your array. Since you only have one parity drive, you can only replace one data drive at a time.

 

My advice, do the parity drive first and then the rest the way you have planned. Do not attempt to do more than one drive at a time.

I must not have been clear.  I have two parity drives.  

[JorgeB]

I mostly upgrade two at a time, but I have full backups, though if anything goes wrong you can use the old drives, as long as the array data was not changed (with btrfs only if the upgrade is done on maintenance mode).

[ashman70]

Well if you have two parity drives, then sure you can do two at a time. As Johnnie says though, make sure you have good backups just in case.

[Harro]

I just did a 2 drive rebuild and all went good but was crossing my fingers all the way. I don't have a good back up to go to. So I prefer to only do 1 rebuild at a time from this point forward. And 5 -10 hour swap is not that long. My 2 rebuild came in at 18 hours which I am happy about at 118.3 MB/s.

Point is swap/rebuild with how many you are comfortable with.

[TODDLT]

3 hours ago, Harro said:

I just did a 2 drive rebuild and all went good but was crossing my fingers all the way. I don't have a good back up to go to. So I prefer to only do 1 rebuild at a time from this point forward. And 5 -10 hour swap is not that long. My 2 rebuild came in at 18 hours which I am happy about at 118.3 MB/s.

Point is swap/rebuild with how many you are comfortable with.

I have true backups of critical info.  That is about 2% of my data... the vast majority of the rest is movies which I still have the original media for.  You can call that a backup, but 1. Just figuring out what exactly was lost on a specific drive would be an undertaking, and 2. We're talking about truly substantial time involved to re-rip them.  Backup.. yeah sorta but not really.  

 

I'm guessing at 10 hours.  My 3 TB rebuilds took about 7-8, but have the older 2 TB slower drives in the mix.  Pre-clears took about 9 hours to write 0s, so I'm hopeful the parity check won't be over 10.  However, as I sit here and think about it, my re-builds may take longer, because until the last one I'll still have at least one old drive in the mix.  12-13 hours maybe.  Don't know really.