topic Re: SnapMirror destination volumes on backup NetApp in ONTAP Discussions

SnapMirror destination volumes on backup NetApp

chaffemccall — Thu, 05 Jun 2025 07:25:27 GMT

Hi everyone, I am new to using Netapp, and we have a 2050 and two 2020's that will be at our DR site.

I am in the process of creating my volumes on my 2020's and have a question about the behavior of the destination volume after I create the mirror.

As an example, I have a volume that hold my exchange database, its called EXCH_SG1_DB and is 60 gigs. On the remote 2020, I created a volume called EXCH_SG1_DB_DR and made it 75 gigs, just to already be larger than the source for future growth.

Well, after create the mirror, i notice the volume will disappear while the job is processing, and then the destination volume shows as 60 gigs, and not the 75 gig it once was.

Can someone with more experience on this explain why this is?

thanks!

James

Re: SnapMirror destination volumes on backup NetApp

eric_barlier — Thu, 16 Jul 2009 21:38:37 GMT

Hi James,

Can you explain a bit more what you mean by: "the volume will disappear while the job is processing"

never should a volume disappear but it does not sound like there is an outage so Im confident there is

a misunderstanding here.

for the size of the destination volume issue, can you run this and post it here

df -g volume_name

vol options volume_name

snapmirror status -l for the relationship

Cheers,

Eric

Re: SnapMirror destination volumes on backup NetApp

chaffemccall — Thu, 16 Jul 2009 21:54:42 GMT

Thanks for the reply. By disappea I meant that on the Netapp Manager (fat client, not web) it will go away from the list of volumes right after I create the mirror. It comes back, but shows the same size as the source volume and not what it was before.

I will post that data later when I am able to.

james

James Zeller

Technology Strategist

Chaffe McCall, L.L.P.

Attorneys at Law

2300 Energy Centre 1100 Poydras Street

New Orleans, Louisiana 70163

Direct: 504-585-7096

Direct Fax: 504-544-6100

Main: 504-585-7000 Fax: 504-585-7075

zeller@chaffe.com http://www.chaffe.com/

Re: SnapMirror destination volumes on backup NetApp

danielpr — Fri, 17 Jul 2009 03:02:12 GMT

Hi James,

When the SnapMirror data transfer to destination happens the destination volume will become unavailable during this process. But it will come online back once its mirrored; this is the current working behavior of Data ONTAP API's. However you can check the volume status using the CLI.

And for the second issue can you send me the output of "df" and "vol status -b". I am doubting "vol status -b" should show your volume provisioned original size (which is before).

Thanks;

Daniel

Re: SnapMirror destination volumes on backup NetApp

alapati — Fri, 17 Jul 2009 13:07:27 GMT

Hi,

During initialization, the volume is restricted and therefore unavailable. As for the volume size, a volume that is a SnapMirror destination volume has fs_size_fixed option turned on (check vol status <vol_name> output to verify this. This is the reason why it shows the volume to be the same size. vol status -b will show you the bigger size of the volume. FS size will be same as the filesystem size of the source. This behavior is intentional. If for some reason, your source volume is grown, SnapMirror can adjust the volume size until it reaches the largest size you created. Hope this helps. I plan to update all this info and auto_grow etc in the next release of TR3446 (SnapMirror Async Best Practices Guide).

Hope this helps

Srinath

Re: SnapMirror destination volumes on backup NetApp

chaffemccall — Fri, 17 Jul 2009 14:09:12 GMT

Here is the output if the DF -G and VOL OPTIONS

Filesystem total used avail capacity Mounted on

/vol/exch_sg1_db_DR/ 60GB 53GB 6GB 89% /vol/exch_sg1_db_DR/

/vol/exch_sg1_db_DR/.snapshot 0GB 3GB 0GB ---% /vol/exch_sg1_db_DR/.snapshot

hstnnetapp> vol options /vol/exch_sg1_db_DR

nosnap=on, nosnapdir=off, minra=off, no_atime_update=off, nvfail=off,

ignore_inconsistent=off, snapmirrored=on, create_ucode=on,

convert_ucode=on, maxdirsize=18350, schedsnapname=ordinal,

fs_size_fixed=on, compression=off, guarantee=volume, svo_enable=off,

svo_checksum=off, svo_allow_rman=off, svo_reject_errors=off, no_i2p=on,

fractional_reserve=0, extent=off, try_first=volume_grow,

read_realloc=off, snapshot_clone_dependency=on

hstnnetapp>

James Zeller

Technology Strategist

Chaffe McCall, L.L.P.

Attorneys at Law

2300 Energy Centre 1100 Poydras Street

New Orleans, Louisiana 70163

Direct: 504-585-7096

Direct Fax: 504-544-6100

Main: 504-585-7000 Fax: 504-585-7075

zeller@chaffe.com http://www.chaffe.com/

Re: SnapMirror destination volumes on backup NetApp

chaffemccall — Fri, 17 Jul 2009 14:17:12 GMT

This is from the DESTINATION:

exch_sg1_db_DR 4096 19660800 15775968

This is from the SOURCE:

exch_sg1_db 4096 15775968 15775968

So, yeah, it does seem that at a block level, the destination, which I created larger than the source is indeed still larger than the source.

Thanks for the information. I am trying to learn all this as much as I can.

James Zeller

Technology Strategist

Chaffe McCall, L.L.P.

Attorneys at Law

2300 Energy Centre 1100 Poydras Street

New Orleans, Louisiana 70163

Direct: 504-585-7096

Direct Fax: 504-544-6100

Main: 504-585-7000 Fax: 504-585-7075

zeller@chaffe.com http://www.chaffe.com/