topic changelog overflow issue in ONTAP Discussions

changelog overflow issue

OkieUnixKanobe — Wed, 04 Jun 2025 09:49:16 GMT

I have an issue where changelog overflow will not zero out.

ONTAP version is 9.8P17

*> volume efficiency show -vserver xxx_sdlc_fc -volume *valu* -fields changelog-usage, changelog-size, changelog-overflow
vserver volume changelog-usage changelog-size changelog-overflow
----------- ---------------- --------------- -------------- ------------------
xxx_sdlc_fc lvol_xxx_valu_01 1% 677.1MB 3.28TB
xxx_sdlc_fc lvol_xxx_valu_02 7% 3.69GB 1.12TB
xxx_sdlc_fc lvol_xxx_valu_03 3% 1.65GB 1.53TB
xxx_sdlc_fc lvol_xxx_valu_04 100% 76.62GB 13.19TB
xxx_sdlc_fc lvol_xxx_valu_05 14% 58.58GB 0B
lhq_sdlc_fc lvol_xxx_valu_06 13% 58.20GB 0B
6 entries were displayed.

:*>
I used the -scan-old-data true option should there be another where those 4 volumes be like 05 and 06?

Re: changelog overflow issue

paul_stejskal — Mon, 15 May 2023 13:12:11 GMT

What is in those volumes? If they are VM datastores, make sure the swap/tempdb files are in a separate FlexVol so they don't cause high change rate. It seems there is high change rate so dedupe cannot keep up.

Re: changelog overflow issue

OkieUnixKanobe — Thu, 18 May 2023 00:03:59 GMT

Yes, which is the reason I thought was happen as nothing showed up in the event log show command other than changelog full. So I end up stopping sis and restarted it with -scan-old-data and -scan-all. That seem to clear it in the end. Just took awhile like 4 to 5 days.

Those were nfs share to linux servers. no any datastores.

Thanks for your help

Re: changelog overflow issue

paul_stejskal — Thu, 18 May 2023 12:31:33 GMT

You're welcome. It might be worth looking at what is on those volumes and seeing what you can do to move any high change rate data into a separate volume anyway.

Glad you got it sorted. 🙂