Reconfiguration Pool
killerodin
33 Posts
September 3, 2020, 1:51 pmQuote from killerodin on September 3, 2020, 1:51 pmIf I have a pool with size 3 and min size 2 and I want to change the pool to size 2 and min size 1 (I know it's not recommendet, but our OSD are RAID5 so it should be ok) what exactly happens then?
We have 2 iSCSI disk on the pool. Will they be offline in this moment? Or will they be slower because of the restruturing? What restrictions do I have to expect?
Thank you and kind regards
If I have a pool with size 3 and min size 2 and I want to change the pool to size 2 and min size 1 (I know it's not recommendet, but our OSD are RAID5 so it should be ok) what exactly happens then?
We have 2 iSCSI disk on the pool. Will they be offline in this moment? Or will they be slower because of the restruturing? What restrictions do I have to expect?
Thank you and kind regards
admin
2,930 Posts
September 3, 2020, 4:26 pmQuote from admin on September 3, 2020, 4:26 pmyes RAID is not recommended, you would be better off using the drives as separate OSDs.
I would not recommend size 2, min_size 1, more importantly the latter as min_size 1 could lead to situation similar to split brain when you have several disks going up and down. Less bad will be to opt for size=2 min_size=2 and rely RAID redundancy but you lose node HA.
When you reduce the size, there will not be any data rebalancing but there will be a lesser overhead of cleanup of the extra replicas by the OSDs, it may slow io slightly.
yes RAID is not recommended, you would be better off using the drives as separate OSDs.
I would not recommend size 2, min_size 1, more importantly the latter as min_size 1 could lead to situation similar to split brain when you have several disks going up and down. Less bad will be to opt for size=2 min_size=2 and rely RAID redundancy but you lose node HA.
When you reduce the size, there will not be any data rebalancing but there will be a lesser overhead of cleanup of the extra replicas by the OSDs, it may slow io slightly.
killerodin
33 Posts
September 4, 2020, 9:06 amQuote from killerodin on September 4, 2020, 9:06 amHi
In this case this is probably out of the question for us.
Thanks a lot
Hi
In this case this is probably out of the question for us.
Thanks a lot
Reconfiguration Pool
killerodin
33 Posts
Quote from killerodin on September 3, 2020, 1:51 pmIf I have a pool with size 3 and min size 2 and I want to change the pool to size 2 and min size 1 (I know it's not recommendet, but our OSD are RAID5 so it should be ok) what exactly happens then?
We have 2 iSCSI disk on the pool. Will they be offline in this moment? Or will they be slower because of the restruturing? What restrictions do I have to expect?Thank you and kind regards
If I have a pool with size 3 and min size 2 and I want to change the pool to size 2 and min size 1 (I know it's not recommendet, but our OSD are RAID5 so it should be ok) what exactly happens then?
We have 2 iSCSI disk on the pool. Will they be offline in this moment? Or will they be slower because of the restruturing? What restrictions do I have to expect?
Thank you and kind regards
admin
2,930 Posts
Quote from admin on September 3, 2020, 4:26 pmyes RAID is not recommended, you would be better off using the drives as separate OSDs.
I would not recommend size 2, min_size 1, more importantly the latter as min_size 1 could lead to situation similar to split brain when you have several disks going up and down. Less bad will be to opt for size=2 min_size=2 and rely RAID redundancy but you lose node HA.
When you reduce the size, there will not be any data rebalancing but there will be a lesser overhead of cleanup of the extra replicas by the OSDs, it may slow io slightly.
yes RAID is not recommended, you would be better off using the drives as separate OSDs.
I would not recommend size 2, min_size 1, more importantly the latter as min_size 1 could lead to situation similar to split brain when you have several disks going up and down. Less bad will be to opt for size=2 min_size=2 and rely RAID redundancy but you lose node HA.
When you reduce the size, there will not be any data rebalancing but there will be a lesser overhead of cleanup of the extra replicas by the OSDs, it may slow io slightly.
killerodin
33 Posts
Quote from killerodin on September 4, 2020, 9:06 amHi
In this case this is probably out of the question for us.
Thanks a lot
Hi
In this case this is probably out of the question for us.
Thanks a lot