VMAX luns: Increasing capacity/migration not an option?

For concatenated expansion you don't have to protect using a BCV.

sergeysh,

               Even if it is a striped meta whihc you want to expand you can follow the same process.

if it's failover clustering then yeah ..will need to take that resource offline briefly to commit PPME session.

what OS is it ?

here is an excerpt from the TimeFinder admin guide, there is still going to be downtime as you will need remove the clone source device, present the target device and then diskpart it.

Copying from a source device to a larger target device

Clone source and target devices no longer have the requirement to be the same size. Now

the size of a clone target device can be larger than the source device. This support requires

the following SYMCLI environment variable be set:

SYMCLI_CLONE_LARGER_TGT = ENABLED

The following limitations apply:

◆ Restore is not allowed.

◆ Full copy support only; must use -nodifferential.

◆ VP Snap is not supported.

◆ Concatenated metadevices are not supported.

◆ When using this feature on striped metadevices you have to preserve the

metageometry. That is, the source and target devices should contain the same

number of metamembers. However, the target device members can be larger than the

source device members.

My understanding is we're not using DAGs with this Exchange environment.

If your connverting Stadard Tdev to a COncatenated meta you have to follow the process

Std dev – Concatenated meta – striped meta   (totaly no disruptive process)

Example to online expand 120G lun to 240G meta lun with 2x120G meta members

Process:
1. Create new 120G device and one 240G BCV device
2. Convert current 120G standard device in use to 240G concatenated meta device – online process
3. Convert 240G concatenated meta device to striped meta device – online process (backend copy will take time to finish but no downtime needed)
4. Verification everything is running as normal.

create concatenated meta

sudo symconfigure -sid XXX -cmd "form meta from dev 10a8, config=concatenated; add dev 40cd to meta 10a8;" commit -nop

convert concatenate to striped meta

sudo symconfigure -sid XXX -cmd "convert meta 10a8, config=striped, stripe_size=1920, protect_data=TRUE, bcv_meta_head=40cb;" commit -nop

Hi All,

Just want to share that I tried to check how much time it takes for expansion of concatenated lun followed by Online conversion to striped meta on VMAX .

converted a thin concatenate lun of 101GB(with 50GB data residing on it) to striped meta and found it takes almost 25 minutes to complete it.

Also it is relative to the amount of tracks it needs to protect to BCV

Hi DP,

as sunmanthn said it depends on the the amount of tracks but also if the device is THIN it depends also how many spindles there are in DATA Pool.

I performed a striped device expansion on  Thin device which the DAT Pool where it was bound comprises of 256 DAT devices and it took 20 minutes for 89GB.

I performed another expansion on a striped Thin device which the DAT Pool where it was bound comprises of 2048 DAT devices and it took me 1 hour 40 minutes for 1TB device.

It depends. And try to do the expansion non working hours becuase it creates overhead to the back end controllers.

Completely agree that all performance impacting Tasks should be executed in off-peak/ non working hours only.

Hi there....I am new to the forum but recently ran into this exact issue.  In my case, the SCSI3 Persistent reservation bit was mismatched between my existing meta and the new TDEV I created to use for the expansion.  The SCSI3 bit on the existing meta was set to disabled and the new TDEV I created had this bit enabled.   As soon as I disabled this bit on the TDEV it showed up as an available device to expand the meta in the SMC GUI.  Anyway, not sure if this is still an active discussion thread but thought I'd share my experience.

yes, this is a well known behavior..

No, It should work by default with BASE license. The command syntax and steps are detailed in SE Array Controls guide