ZFS Snapshots Size Issue

[RainbowDinosaur]

Current state : zpool 82% full

I'm trying to do a ZFS snapshot of my current dataset (used for storing database data) and send it over (using zfs send/recv) to another server for backup purpose.

However, the moment after I did a zfs snapshot, the snapshot size grows quickly ~= 100M/sec (probably because my dataset is changing rapidly)

I'm worried that before the send/recv is able to complete, I will face out of storage issue.

Is there any alternative ways I can snapshot safely and send (to a file, server, etc), beside stopping my database service?

 

[Ericloewe]

No. This is another reason not to skimp on storage.

 

[leenux_tux]

Have you tested how long it takes to do a snapshot with the database services switched off ? If its only a minute or so you could then schedule the snapshot for a quieter time?

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[RainbowDinosaur]

No. This is another reason not to skimp on storage.

This is a valid point - however i'm currently out of disk bays to add new storage. The future plan will probably be upgrading the disks 1 by 1 or get some-sort of expander.
But my main goal is to get a snapshot fast for backup purpose.

 

[RainbowDinosaur]

Have you tested how long it takes to do a snapshot with the database services switched off ? If its only a minute or so you could then schedule the snapshot for a quieter time?

Sent from my A0001 using Tapatalk

Taking the snapshot is rather instant (even without switching the database service off). However, the main concern I have is the snapshot grows very fast while the database service is on.

 

[pro lamer]

Have you tested how long it takes to do a snapshot with the database services switched off ? If its only a minute or so you could then schedule the snapshot for a quieter time?

@leenux_tux: have a look here: https://www.google.pl/amp/vnugget.com/oracle-solaris/understanding-zfs-snapshot/amp/

EDIT: or here: manual, chapter "ZFS primer", chapter 28 IIRC - snapshots grow over time.

 

[pro lamer]

Taking the snapshot is rather instant (even without switching the database service off). However, the main concern I have is the snapshot grows very fast while the database service is on.

Some wild guesses (EDIT: am a noob): Maybe you can try:

• making another snapshot and send them one at a time - EDIT: maybe both of them or at least one of them grows slower...
• And similarly to what @leenux_tux wrote: maybe you can send/recv on quieter time = when database iops are lower = when snapshot size grows slower
• EDIT: Combining the 2 above: deleting the snapshot you have just taken, so it stops growing then waiting for quieter time then taking two snapshots one shortly after another and send/recv right after...

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