SLOW Windows 2003 software raid-5

Trann · 1 Aug 2006 at 12:54

My computer setup:
AMD XP1600 Socket A
Abit KG-7
768 MB ram
1x120gb IDE
4x320gb SATA
PCI SiI3114 Sata Controler
Windows 2003

The problem:
I have the 4x320gb disks set up in a windows 2003 software raid-5 setup, which is extremely slow.
It starts off at ~20mbyte/sec and after about 10 seconds slows down to 1mbyte/sec.
Doesn't matter if i'm copying over a network or from the system disk (120gb IDE)
These speeds are AFTER the array has Synched, and is labeled as healthy in disk management.
I have tried deleting the array and setting it up again as a spanned or striped array and the speeds with that setup are fine, so it's not the PCI SATA controler that is limiting me.
I'm using NTFS formatted with "default" cluster size.
The Win2003 setup is pretty much brand new, i haven't changed any settings, so they are all set to default values.

Any ideas?

Trann · 1 Aug 2006 at 16:58

Datamonkey said:
the problem is in your title mate,

software raid 5- this is asking a lot of your system.

Software raid 5 would be taking quite a lot of cpu cycles to keep it all upto date.

Sorry to say, the best way around your issue would be to see if you can purchase a cheap raid controller card which is hardware, even then most cheap ones still rely on some cpu usage.

Hmm ok you do have a point, but i did go check it out, copied a file from my 120gb disk to the raid array, and while the speed was going fine (as it always does the first 5-10 seconds) the CPU usage was in 100%. I thought i had found my problem.
But then, when the file transfer rate dropped after 5-10 seconds like it alywas does, the CPU usage dropped as well, it didn't go above 20% for the next 2 minutes it took to fininshing copying the file.

Buying a hardware raid controler is not an option. One that supports 5+ disks (i have one more 320gb disk that i haven't plugged in yet) costs several hundred quid.

Trann · 1 Aug 2006 at 17:00

bledd. said:
software raid is a POS, should never have been invented!

buy a raid card if you must use it!

-edit, oh you have a raid card

in that case go into the bios for the raid card (F2 probably?) when its detecting drives, and create a raid array in there (all data will be lost that is currently on them)

No i don't have a raid card, it's a sata card that doesn't have raid capabilities.

I have looked on other forums about win2003 software raid-5 and no one has complained about speeed. I found this thread on one forum that had 5 pages worth of replies and people were getting at least 40mbyte/sec write speeds. I only need 1/4th of that.

Trann · 1 Aug 2006 at 17:19

bledd. said:
40mb/s? you can get that on a normal ide 80gb hard drive no problem..

software raid is just rubbish mate, invest in a sata raid card, you won't regret it!

edit, the 3114 is raid isn't it? (the 3112 is anyway..)

I wasn't saying that 40mb sec was great. I am however getting below 1mbyte/sec, which i think is not due to the fact that this is software raid, rather something else.

Trann · 4 Aug 2006 at 10:53

I did try to reinstall win2003 on my desktop computer, which is a 3500+ AMD with 1 gbyte RAM, with the exact same issue. My 3500+ computer even has 8 built in SATA connectors and i tried spreading the drives over those and no diffrence.

Good write speeds for about 5 seconds, then everything deadlocks.

The cpu usage is pretty high for those first 5 seconds, then drops to below 10%.

It does however completly eat up my ram in those first 5 seconds, goes from 750 mb ram free to 100 mb ram free in 5 seconds, then everything stops.. It's really weird..

I've tried increasing the cluster size to 8mb from 32 kb, which in theory would make the CPU have to do 250x less parity calculations, but it didn't change a thing.

The issue defenitly lies in the Raid-5 part though, as i don't expirience this when i set the array up in spanned or striped mode.

I'm really at a loss here, i've read about tons of people using win2003 raid-5 without any issues on mid range home servers, but no matter what i do it sucks for me

Trann · 4 Aug 2006 at 15:02

Thanks for taking the time to reply, but i'm really not interested in hearing that "software raid sucks", because that's just not the fact.

Like i've already said at least 2-3 times in this thread, there are plenty of people that run win2003 software raid-5 with good results, including [email protected] who had nothing but good stuff to say about it.

I've pretty much given up though and just set up a spanned array, hoping that one of my 5 disks don't go MIA for the next 2 years or so.

Trann · 4 Aug 2006 at 15:21

I can't even find a SATA raid-5 controler that supports 5 disks and fits in a PCI bus, only one i can find is pci-x and costs 250 pounds here in iceland.

So yeah, hardware raid is not really an option.

The article i'm reffering to is this one
http://www.tomshardware.com/2004/11/19/using_windowsxp_to_make_raid_5_happen/page6.html

This isn't even on win2003 heh, it's winxp hacked to do the same thing as win2003, but i figure it's the same thing.. and he's using a 2.8 ghz p4, and is getting pretty decent results. Results i'd be more than happy with, if i could get them.

Trann · 4 Aug 2006 at 15:22

Wyvern971 said:
What else have you got running on the server?

Nothing at all. completly new OS install

Trann · 4 Aug 2006 at 15:47

Wyvern971 said:
Sounds a bit strange have you got recent drivers (in particular for your network card)?

Also can you try another network card (I've had one before where it appeared would be near 100% CPU use, when I tried a new network card it worked fine)

Yep i've tried a diffrent network card, and in fact i've tried a completly diffrent computer with nothing in common but the hard disks and the operating system ( did reinstall it though)