EMC VMAX to the All-Flash market – VMAX All-Flash arrays

On Monday (29-Feb), EMC announced their All-Flash models of VMAX arrays. With the addition of All-Flash version of EMC VMAX 3 series of arrays, EMC is targeting to continue to maintain their position in today’s busiest storage market – the AFA Market. These new additions to their Flash Storage portfolio – alongside the existing XtremIO and the new DSSD – will help them serve different customer requirements and thus to remain in race.

VMAX All-Flash-Arrays come in different models including 450F/FX and 850 F/FX.

VMAX All-Flash

As in the above snap, VMAX 450 F/FX and 850F/FX arrays gives unmatched performance with 4M IOPS and <0.5ms latency. The HYPERMAX OS is well optimized for Flash in the new products to achieve lowest latency in a high density system. It can have 1PB of usable space over a single tile space.

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Hardware : VMAX 450 and 850 systems comes with V-Bricks which are equivalent to the engines in previous models. Each V-Brick with 2 directors which can have 1TB (for VMAX 450) or 2 TB of memory. A single VMAX 450/850 cabinet can have upto 2 V-Bricks and 480 drives. Customers can upgrade -Scale Up- the capacity in 13TB flash packs and Scale-out the performance by adding more engines.

Software : The F and FX model variations have different software packages in the system. The F variations (450F and 850F) have HYPERMAX OS, SnapVX, and AppSync starter pack. Customers can add more software packages as a-la-carte options. In FX variation, have more software packages by default in addition to the ones available with F models. These include Remote replication suite (SRDF Sync/Async, STAR, SRDF/Metro), CloudArray Enabler, eNAS, [email protected], ViPR Suite etc…  customers can have remaining packages in a-la-carte.

VMAX AF-Software

VMAX AF systems will offer multi-dimensional scalability (Ports/ Devices/ Capacity), World class BC/DR (With SRDF and SnapVX) and various data services including Mainframe, eNAS etc… This will cater different customer needs when compared to the XtremIO from EMC All-Flash family. More to come in near-future as they plan to have even denser configuration as they switch to newer high capacity SSDs.

AvailabilityVMAX AF series of systems are now available for customers.

Administering a VMAX-3 series system ? A few things you have to consider..

EMC VMAX-3 series systems were launced almost an year back, and more and more customers are going for VMAX-3 now. From an administration perspective there are few differences with VMAX-3 from the previous VMAX series.


You may read the architectural differences in my previous posts on VMAX-3 series. Let’s discuss some of the most important things to be taken into consideration while creating new devices with the new product series..

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No Thick devices:

VMAX-3 series does not support thick devices. All devices are thin devices and space will only be allocated when the system start writing data into it. And the thin device extent is 128KB (improved granularity from 768KB in previous models).

No Meta :

VMAX-3 series does not support meta device creation. With the maximum size of single device support in TBs (240GB is the max size of a single device in VMAX 2nd gen), there’s no need of a meta creation.. 🙂

As meta is not supported, auto meta feature also is not available with VMAX-3 series. You will find N/A for the auto meta feature in symcfg list -v output instead of enabled/disabled.

Increased track size :

VMAX-3 now have a track size of 128KB. It is now doubled from 64KB (1 track = 64KB with the previous generation of VMAX systems) and hence a Cylinder in VMAX-3 is 1920 KB (With VMAX series it was 960KB). This is very much important to remember this during device creations.

More in coming posts… Your thoughts in comments. Thanks.

VMAX – Expanding a Thin pool via symcli

We had discussed about deleting a Thin pool here in one of our previous post. Now we will discuss how to expand a thin pool via symcli, i.e, adding more TDATs to the pool.

We can first make a note of pool details by running,

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symcfg -sid 1234 show -pool T_Pool_1 -thin -detail

We have to identify the candidate TDATs, which can be added to the pool. We have to find the nonpooled TDAT devices from the required disk group.

symdev list -sid 1234 -datadev -disk_group 3 -nonpooled

This will list all the TDATs from disk group 3 which are not part of any pool. We can select the devices as per our size requirements etc…  Here we have identified the devices AAAA through BBBB as the candidate TDATs.

The below command will add those devices to the pool,

symconfigure -sid 1234 -cmd “add dev AAAA:BBBB to pool T_Pool_1, type=thin, member_state=ENABLE;” commit -v -nop

If you are not using the member_state=ENABLE , the added TDATs will be in disabled state and you will have to manually enable them by running,

symconfigure -sid 1234 -cmd “enable dev AAAA:BBBB in pool T_Pool_1, type=thin;” commit -v -nop

Once you have the devices added and enabled , you will be able to see the new TDATs under the enabled devices in show -pool command output. Now the data is there in the existing TDATs and you will have to do a re-balancing of the data in pool by running the below command,

symconfigure -sid 1234 -cmd “start balancing on pool T_Pool_1, type=thin;” commit -v -nop

You can verify the pool state by running the show -pool command. The pool state now should be rebalancing from enabled.

Now you may change the maximum subscription limit for the pool. If you don’t want over subscription for the pool, you may set the maximum subscription percent as 100, otherwise can be some values higher than 100.

symconfigure -sid 1234 -cmd “set pool T_Pool_1, type=thin, max_subs_percent=100;” commit -v -nop

So that’s it you have added the devices to pool and balanced it. Now you should be able to see the added space and will be able to bind more thin devices to your pool.


VMAX – deleting a thin pool, its easy…

Here we will discuss the procedure to delete the thin pool. Thin pools will be containing DATA devices and will have TDEVs (Thin devices) bound on it. Let’s go through the procedure in detail.

For deleting a thin pool,

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1. Ensure no thin devices (TDEVs) are bound to the pool.

2. All the TDATs should be in disabled state.

You can check the pool status by running the command,

symcfg -sid xxxx show -pool T_Pool_1 -thin -detail 

This will show the pool state and details including TDEVs bound and enabled TDATs. If there are any TDEVs bound to the pool, you  may either migrate the data to a different pool, or you can unbind the devices by running the command (if there are no data in it)

symconfigure -sid xxxx -cmd ” unbind AAAA:BBBB from pool T_Pool_1;” commit -v

*** NOTE : Unbinding the TDEVs will wipe out all data in it ***

where AAAA:BBBB are the TDEVs bound on the pool. This will unbind the devices from the pool, which usually takes some time depending on the device size.

Once this is done we can disable the TDATs from it. Use the below command for disabling the devices,

symconfigure -sid xxxx -cmd “disable dev AAAA:BBBB in pool T_Pool_1, type=thin;” commit -v 

Once disabling is done, the pool state becomes disabled, from enabled or rebalancing or whatever it was.

You may verify this by running the show -pool command.

Now we can remove the TDATs from pool before deleting the pool. The command will be,

symconfigure -sid xxxx -cmd “remove dev AAAA:BBBB from pool T_Pool_1, type=thin;” commit -v 

Now we are all set to delete the pool. Issuing the below command will do it for you.

symconfigure -sid xxxx -cmd “delete pool T_Pool_1, type=thin;” commit -v 

Deleted ?, you can verify it by running the list -pool or show -pool command.

symcfg -sid xxxx list -pool -thin -gb -detail

Yes, the pool T_Pool_1 is not there. So we are done..! You may refer to this post for expanding a thin pool.

GB to/from Cylinders conversion ? Converters for you..

While working with EMC symcli , it is a challenge for the beginners, the storage administrators to convert the device size (GB/MB) to number of cylinders and vice-versa. VMAX and DMX volume operations are often performed with the device size in cylinders mentioned.

So here in this post I have put 2 converters to make these calculations easier.


The equations for performing these calculations are simple, as below. An excel sheet with the below formulas will help you to perform the calculations offline.

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Size (GB) = No: of Cylinders x 15 x 128 x 512 /(1024 x 1024 x 1024)
No: of Cylinders = [ Size(GB) / (15 x 128 x 512 ) ] x 1024 x 1024 x 1024

Now here are the converters :

GB/MB to Cylinders/Tracks 


Cylinders to GB/MB/KB/Tracks

Hope this helped you. For working with symcli in offline mode, you may refer to this post.

Note : This converter is applicable for size calculation for VMAX and DMX (with enginuity 5771+ ) devices only.