HA - Slow Sync - Need Sync Design Guidelines

[SANman]

I am experiencing a slower than anticipated initial sync or FULL sync times on my HA Targets.

The following are my hardware, OS and logical config.

Software Version: StarWind 5.5 Servers with RAID Controller: 3Ware 9690SA 8-Port SAS/SATA
Hard Drives: Seagate Barracuda ES.2 ST31000640SS 1TB 7200 RPM 16MB Cache
RAID-5: 5 x 1TB (above drives)
Physical LUN: 3.63 TB
HA Node OS: Windows 2k8 R2 (standard)
RAID-5 Partition: Basic Disk - GPT - NTFS - Primary
HA Target: 500GB - 2048 MB Write-Back Cache, 1000ms Expiry Period

Dedicated sync/mirror 1Gbps NIC: Full-Duplex, Jumbo Frames and Flow Control Enabled.
Dedicated switch with Jumbo Frames and Flow-Control Enabled for SYNC/Mirror

I set up a 500GB HA target but it looks like it is going to take somewhere between 36-40 hrs to complete the initial sync! I am assuming a FULL resync later on would take the same amount of time? I am able to get 35-40% NIC utilization when doing a FULL sync on a smaller HA target, so I know the NIC interface is performing at new full speed.

I know there is a lot of layer involved in designing and analyzing the overall I/O performance of a storage system.

My Questions are:
1) Does this seem normal for the hardware config I have?
2) Is there a design guide/Best-Practices guide that gives some guidelines?

24 hrs for a FULL sync on a 500GB target seems very long. There is not way I can survice a 24hrs of degraded performance if a FULL resync is needed.

When the HA Target is synced, Performance seems to be fast and stable.

Any help or insite would be great! Thanks

[anton (staff)]

That's too slow... With ~50% link utilization (keep in mind, Windows says 100% when data goes both sides at the same time for full-duplex configured NIC) if your cross-bar link does wire speed with TCP (Does it? Please check with IPerf & NTtcp and let us know) you should be done in ~1,5 - 3 hours (assuming NO heavy load on degraded storage cluster). So start with checking performance between two points (HA1 and HA2 nodes) and checking write performance on your RAID. Both RAID5 and Areca cards are known to have issues (even separately). Does it sound like a plan?

P.S. Upcoming version 5.7+ will have automatic performance monitor & configuration verifier. FYI.