topic Re: How can we store more than 255 snapshots per LUN in ONTAP Discussions

How can we store more than 255 snapshots per LUN

fujitsusiemens01 — Thu, 05 Jun 2025 07:17:13 GMT

Hi folks,

We have a customer request for a storage unit which can support a minimum of 750 snapshots per LUN.

Two questions....

1) Which creative method can we employ to bypass the standard 255 snapshots per LUN? Preferably online, but this is not indicated in the original request.

2) Which compeditorsystems do we know which can support more than 700 snapshots per LUN?

Thanks in advance for your responses.

Regards

Re: How can we store more than 255 snapshots per LUN

roman_verysell — Mon, 15 Mar 2010 09:35:06 GMT

SnapVault?

http://www.netapp.com/us/products/protection-software/snapvault.html

http://www.netapp.com/us/library/technical-reports/tr-3252.html

http://www.netapp.com/us/library/technical-reports/tr-3667.html

Re: How can we store more than 255 snapshots per LUN

fujitsusiemens01 — Mon, 15 Mar 2010 09:44:38 GMT

Hi Roman,

Thanks for your response and yes Snap Vault could help somewhat, but the customer for some reason has indicated the need for over 700 snapshots per LUN !?!?

This is also why I am searching, which competitor can provide this option?

Regards

Re: How can we store more than 255 snapshots per LUN

roman_verysell — Mon, 15 Mar 2010 17:55:08 GMT

Just try to find something like: "1024 snapshots per lun volume" in Google.

For ex: AMI StorTrend

"Redirect on Write (ROW)

Up to 1024 snapshots (R/O and R/W) per volume
Up to 2048 snapshots per box"

It's ridiculous low-end disk box, but it's really (I hope) exist.

Re: How can we store more than 255 snapshots per LUN

scottgelb — Mon, 15 Mar 2010 18:18:41 GMT

You could create a flexclone of the volume with the lun (no additional overhead for the clone) then start creating snapshots on the clone... so you could get more than 255 snaps by mixing snapshots with Flexclone... would take some scripting or management...but maybe when you hit snapshot 254, create 255 then a clone of 255 and start over on the new clone volume... this is described in the online backup guide for snapvault but could be used for any volume.

Re: How can we store more than 255 snapshots per LUN

radek_kubka — Mon, 15 Mar 2010 19:57:19 GMT

Hi all,

Just a couple of thoughts:

I am wondering what could be the compelling reason to actually keep, say, 100+ snapshots online?

Does the customer in question actually know how to manage hundreds of snapshots per LUN?

Regards,
Radek

Re: How can we store more than 255 snapshots per LUN

roman_verysell — Tue, 16 Mar 2010 07:12:00 GMT

great thought, scottgelb!

Flexclones are independent from snapshots, every flexclone-vol can get 254 snapshots.

Re: How can we store more than 255 snapshots per LUN

roman_verysell — Tue, 16 Mar 2010 07:16:35 GMT

There is no reason for keeping so incredibly big amount of snapshots, Radek.

I think, it's just for punching out NetApp's alternate offer from the customer's project, who already make his choice.

Re: How can we store more than 255 snapshots per LUN

fujitsusiemens01 — Tue, 16 Mar 2010 10:02:39 GMT

Hi Roman,

There are two possibilities....

Either as you state, it is a move to keep Netapp "out", or the customer just has no idea as to how snapshots work and what their use is.

Unfortunately we can not determine which it is as this is more of a tender situation and we have therefor not spoken to the customer.

I think the flexclone solution would offer us a way to "bypass" the demand for 700+ snapshots minimum as a strict requirement. But I still think that if this is a

"problem" for a Netapp environment, would it not also be for EMC/DELL/IBM/HP/HDS unless this government department wants to keep out all the big

players. Surely they did not come up with this figure by coincidence??

Regards

Re: How can we store more than 255 snapshots per LUN

scottgelb — Tue, 16 Mar 2010 19:52:50 GMT

Good discussion here... I agree that a customer would have a tough time explaining why 255 snapshots is not enough... but I have found rare cases where competitors with "unlimited" (well, test performance with that...) snapshots get a checkbox over us... in that case, I use the flexclone method to show we are unlimited too... if we exceed a node volume count or clone count, vol copy or mirror the volume and start snapshots over that way too (2 full copies only but you can scale unlimited...).. even though this is not feasible and not even an edge case we are likely to ever run into, it is a way to match the competitor who convinced the customer they need this feature.