HPE EVA Storage

Slow copy of small files on EVA 4400 / W2K8 R2 virt. Machine

 
IQ
Occasional Advisor

Slow copy of small files on EVA 4400 / W2K8 R2 virt. Machine

Problem:

File Copy from Volume A to Volume B and vice versa. If I copy 4GB files with an average size of 400MB I get a copy speed of 120 MB/s. If I copy 4GB files with an average size of 1MB the speed is about 5 MB/s.

I know that copying small files will always result in a lower copy performance, but in this case the throughput for small files is 4% of the possible throughput. That is a real drastic drop of performance. I would expect something like 25-35% of the original speed, but not 4%.

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Environment:

The two VDISKs in question are located on a EVA 4400, XCS Version 09534000. They are both configured with VRAID5. They are residing on different disc groups. One disc group consists of ten 400GB 10k FC disks (BD400DADFQ) and the other consists of eight 1TB 7,2k FATA disks (NB1000D4450). All of the Disks have afaik the newest firmware. HP03 for the FC disks and HP07 for the FATA disks.

The disks are presented to an virtual machine running on Hyper-V R2.

The host is a ProLiant BL460c G1 (AL585A) inside a C3000. The newest Microsoft patches for W2K8 R2 released on the last patch day are already installed. The newest PSP (8.60) is installed as well. So the drivers / firmware of the Blade should be up to date. The EVA MPIO provider 4.4 is also installed. SAN switch is: Brocade 4/12 SAN Switch for HP c-Class BladeSystem (AE370A) Firmware 6.2.2c.

The guest OS is also W2K8 R2. Newest Microsoft patches. The vdisks are presented as pass through disks. Both volumes are NTFS formated with the Windows default block size of 4kb.

According to "evaperf hps", "as" and "cs" the fibre channel traffic was equally devided to all of the four host ports, the array controller CPU % and Data % usage were under 10% and the total host Requests/s and MB/s weren't high (tried this late at night so that user access wasn't the problem).

I had to use normal Windows copy and paste. I know that it doesn't have a decent performance, but a copy performance drop of 96%? I couldn't avoid the default copy and paste, even if I wanted to because the customer doesn't want to use anything else.

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So the question is: Is there a posibility to speed up the copying of the small files?
4 REPLIES 4
Jan Soska
Honored Contributor

Re: Slow copy of small files on EVA 4400 / W2K8 R2 virt. Machine

Hello Thomas,

I am afraid your problem is quite common.
Why are you coping this files? Backup reason?
If yes, try to do it on block way - as clone of disk directly on Eva. If you need to restore it, just attach clone as new lun and recover requested files.
Of course, you need bizniss copy EVA licence for it...

Jan
Víctor Cespón
Honored Contributor

Re: Slow copy of small files on EVA 4400 / W2K8 R2 virt. Machine

1 MB files are no small, that would be if we talked about 8K or less. The disk groups are small, but they can manage 70 - 80 MB/s on sequential writes as minumum.

Can you do a test from a non-virtual Windows machine?
IQ
Occasional Advisor

Re: Slow copy of small files on EVA 4400 / W2K8 R2 virt. Machine

I already did a test on a normal Windows installation. The difference isn't much, maybe two or three MB/s.

So it seems, that the virtual machine isn't the culprit.
Michael A. McKenney
Respected Contributor

Re: Slow copy of small files on EVA 4400 / W2K8 R2 virt. Machine

When I first installed my MSA 2012fc, I tested RAID 5 vs RAID 10 write performance. I found RAID 10 was much better. I was manaully moving 750 GB of data across 4 x 1 Gbps trunked NICs on each server to the SAN LUNs. I also changed the block size of the Windows data paritions to 512 Kb to limit cluster loss.

You are limited by network speed, disk writes, and Windows copy. I found xcopy from cmd prompt was faster than Windows copy. RAID 10 does not do parity writes and calculations to slow down the process. RAID 10 vdisk array does lose disk space, which I was not concerned about.