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A comment on We saved millions in SSD costs by upgrading our filesystem. Parent comment

Re:We saved millions in SSD costs by upgrading our filesystem by shrubble on Tuesday November 09, 2021 @02:26PM (#29166227)
It seems shocking to me, that you haven't yet migrated, however you know your costs/benefit ratio more than I do. Have you ever examined a split model, where some parts of the load are run on your own or rented dedicated servers, and some runs on AWS?

Separately to your comment about LVM... the LVM snapshot requires that a separate part of the volumes be set aside to hold the snapshot data.

If the snapshot volume fills up with changes being made to volume that holds your data before the snapshot completes, then the snapshot will fail.

This does not occur with ZFS as you have noticed.

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Re:We saved millions in SSD costs by upgrading our filesystem by nine_k on Tuesday November 09, 2021 @06:27PM (#29168970)
With the price of the egress being what AWS charges, such a split may still not make economical sense if it crossed a data-intensive boundary.

Also, with many customers also using AWS, much of the traffic may not even leave a datacenter, improving speed, reliability, and maybe even cost.

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Re:We saved millions in SSD costs by upgrading our filesystem by mhio on Tuesday November 09, 2021 @08:05PM (#29169846)
> This does not occur with ZFS as you have noticed

I'm not sure exactly what "This" refers to? Just wanted to note that a ZFS snapshot can be destroyed when the parent pool runs out of space too, but you don't need to allocate a volume.

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Re:We saved millions in SSD costs by upgrading our filesystem by shrubble on Wednesday November 10, 2021 @03:50PM (#29180564)
For LVM you usually have to pre-allocate the space. So perhaps you think that you will need 8GB to hold the changes during the snapshot operation, and it works great for 6 months until more data is added and 1 customer does a lot of small updates during their maintenance window, which overlaps with your backup schedule... and the snapshot operation fails. No data is lost in this case, but the back up doesn't finish.
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