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Vlkoun
Contributor
Contributor

Very poor HDD performance

Hi

I have a problem with my server setup.

HP ML350 G6 12MB RAM ESXi 4.1

P410i 512MB:

3x146GB 10k 2.5 RAID5 for win 2008 sbs, win 2003, win xp

2x600GB 10k 2.5 RAID1 for data

P210 in PCI slot:

1x2TB 7.2k for acronis secure zone and non essensial data

Few weeks ago, my backup became really slow. Full SBS backup in Acronis takes more than three days. As my 3 years old HP HDD had some predictive failures I've decided to buy new Seagate Const ES.3 SAS HDD. But unfortunatelly there is no speed improvement. Sequencial copying from Data Raid to backup HDD is only around 1-3 MBps. I guess it is because of extremly big latency 700-800 ms of that backup drive. Other two drives have 1-10ms latency.

What could be a reason of this?

Thanks a lot.

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4 Replies
a_p_
Leadership
Leadership

Issues like this are often related to a missing or faulty BBWC battery. Without the battery, the controller will default to write-trough mode, which is significantly slower than write-back mode with battery backed write-cahe enabled.

André

Vlkoun
Contributor
Contributor

I've already found your explanation of write back vs write trough mode.

I have backup battery only for internall P410i. P212 has no backup battery so I guess it's in write trough mode. But what is strange, backup drive performence was way better few months ago and I haven't change anything in bios or raid setting.

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bjm534
Enthusiast
Enthusiast

I would check network connections for something like a speed/duplex issue.

-Brad
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Vlkoun
Contributor
Contributor

That bad performance is also when copying within server disks not via network. Also network is fine. I can download files from data raid at 50-100 MBps rate but from backup drive at 1-3 MBps. I understand BBWR is a lot better but still 1-3 MBps and 700 ms latency? That doesnt seem ok even for non memmory P212 does it?

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