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symsnap -concurrent option
I am having trouble understanding what the -concurrent option on the symsnap create and activate acutally do. I need two sets of snap devices for each application. Rather than creating one device group with two sets of VDEVs for each STD, I have created two device groups, appSNAP1, and appSNAP2, each with the same set of STD devices and a different set of VDEVs. This makes it easier to get the VDEVs I want on a simple create, activate or terminate. I think I get the same result creating or activating the second set of VDEVs using the second device group regardless of whether or not I include the -concurrent option. I was thinking that maybe its because i am using two seperate device groups, and the concurrent option is irrelevant in this case. But I'm pretty sure that earlier in my testing when I was working with a single device group and two sets of VDEVs, I was gettting the same result without the -concurrent option, which I wasn't even aware of at the time.
I would appreciate any light that anyone can shed on this.
MikeMac1
292 Posts
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July 18th, 2014 08:00
Per the Solutions Enabler SYMCLI 7.3.1 Command Reference, here is what the Concurrent flag does:
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.
Here is some additional information from teh Solutions Enabler Symmetix TimeFinder Family CLI Version 7.3.1 Product Guide:
Pairing an additional target device with each source device in a group
When working with either a composite or device group, you can use the
-concurrent option with the create action to pair an additional target device with
each source device in a group.
To pair an additional target device with each source device in group ProdDB, enter:
symsnap -g ProdDB create -concurrent
When the copy session is created, an additional target device will be paired with each
source device in the group. For example, if there were two target devices paired with
each source device in the group before activating the session, there will be three target
devices paired with each source device after the session is activated.
To verify that each source device in the group has multiple targets, enter:
symsnap -g ProdDB verify -created -concurrent
When working with either a composite or device group, you can use the
-concurrent option with the activate action to activate an additional copy session
for each device pair in a group.
To activate an additional copy session for each device pair in group ProdDB, enter:
symsnap -g ProdDB activate -concurrent
wwsmith1
3 Posts
0
July 18th, 2014 10:00
Yes, I have read these sources, but as I said in original post, I get the same results if I don't include the -concurrent option on the create and activate, at least in the situation I've described.
Fenglin1
2.1K Posts
1
July 27th, 2014 23:00
-concurrent option with the establish command to activate an existing clone session for an additional clone pair in a group. So this meand the option is only for additional pairs with in one group.
If you have source 0111,0121 and VDEV target 0112,0113, 0122,0123 in device snapdg
–Creates the first Snap session between 0111:112 and 0121:0122
symsnap create –snap_pool
-Activates the first Snap session
symsnap activate –consistent
–Creates the second Snap session between 111:113 and 121:123
symsnapcreate –snapa_pool –concurrent
–consistent –Activates the second Snap session
symsnap activate
rawstorage
419 Posts
1
July 28th, 2014 00:00
I wrote a KB article on the usage of this many moons ago.
https://support.emc.com/kb/10039