Ampofo
1 Copper

Can you snap a device that is already a source for another snap?

Can you snap a device that is already a source for another snap? I am trying to snap the source of a snap and have two snaps of the same source device. HAs anyone done this before? How did you do it? Thanks

0 Kudos
6 Replies
dynamox
6 Thallium

Re: Can you snap a device that is already a source for another snap?

yes, you can have up to 14 snaps of one device i think.

0 Kudos
Ampofo
1 Copper

Re: Can you snap a device that is already a source for another snap?

dynamox , my question " how to create two snaps of the same device"

0 Kudos
dynamox
6 Thallium

Re: Can you snap a device that is already a source for another snap?

add devices to a text file and run symsnap create command, for example text file 1 looks like this:

303C 1FD2

text file 2 looks like this:

303C 1FDA

so you snap these with this command:

symsnap -sid 123 -f file1.txt create

symsnap -sid 123 -f file1.txt activate

repeat the same steps for file2.txt and you end up with two different snapshots of the same source device.

0 Kudos
dynamox
6 Thallium

Re: Can you snap a device that is already a source for another snap?

i have not looked into this but looks like you could do a lot more now

Multivirtual snaps

With multivirtual snaps enabled, Solutions Enabler supports up to 128 snaps from a
source device. This support requires that you enable the following SYMCLI
environment variable:
SYMCLI_MULTI_VIRTUAL_SNAP = ENABLED
This setting appears in the snap device output from symdev show. The Snap State
Flags value will be MultiVirtual.
A single source device can only have snaps of one type.
Note: Multivirtual snaps are not supported with the Auto Cancel policy. Starting with
Enginuity 5874 Q2 SR, multivirtual snap operations are supported with CKD devices. Snap
recreate for multivirtual snap operations is supported in environments running
Enginuity 5875 and higher

0 Kudos
GEMC
2 Bronze

Re: Can you snap a device that is already a source for another snap?

I believe default maximum number of snap sessions is 16. If you enable Multi Virtual Snap, then you can have 128 snap sessions.

Set the variable:

SYMCLI_MULTI_VIRTUAL_SNAP=ENABLED

#symcli -def --> You can verify the variable setup.


This is only for your understanding !


######Add the Source and First set of VDEVs in a DG and Create First snap session:-

#symld -g TEST_DGROUP addall dev -range <devid:devid> -sid 123
#symld -g TEST_DGROUP addall dev -range <devid:devid> -vdev -sid 123

#symsnap -g TEST_DGROUP create -svp DEFAULT_POOL -nop
#symsnap -g TEST_DGROUP activate -consistent -nop
#symsnap -g TEST_DGROUP query -v

######Add the second set of VDEVs in the same DG and create Second snap session:-

#symld -g TEST_DGROUP addall dev -range <devid:devid> -vdev -sid 123

#symsnap -g TEST_DGROUP create -svp DEFAULT_POOL -concurrent -nop
#symsnap -g TEST_DGROUP activate -consistent -nop
#symsnap -g TEST_DGROUP query -multi

Can someone please confirm the commands?

I think we need to activate the second snap session with "-concurrent" option. I am not sure. Can someone clarify this please????

Thanks.

0 Kudos
GEMC
2 Bronze

Re: Can you snap a device that is already a source for another snap?

We should activate the second set of snap pair device with -concurrent option.


Man page description:  -concurrent -->   When specified with the verify argument, this option verifies the standard device and multiple target devices. When specified with active commands, this option performs the operation on a pair with an additional target device.

0 Kudos