Works in Win2012 (w stor spaces) but I have some questions.

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dustyny
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Works in Win2012 (w stor spaces) but I have some questions.

Post by dustyny »

Hi,

I just wanted to let you guys know I did some testing of running FancyCache in Windows and it seems to work with no problems other then the ones mentioned here already. I was able to use FancyCache in combination with storage space with no problem.

Here is my test machine
Core i7 970
24GB
2xIBM m1015 SAS controller
8xOCZ Vertex 3 120GB SSD
8xWestern Digital Enterprise Class (RAID) 1 TB HDD

Setup:
I created 2 storage spaces, one for each drive type. One for the 8 HDDs and one for the 8 SSDs.
A 8xHDD storage pool was created with a thin provisioned 1 TB drive, using Parity (RAID5, Striped w/Parity).
A 8xSSD storage pool was created with a thin provisioned 1 TB drive, using simple (RAID0, Striped).

Obviously the product is still in beta, so I'm sure my results maybe as a result of unfinished or code that hasn't been optimized but I figured I'd give my feedback to help move you guys along. :)

I'm using the ATTO drive benchmarking tool to create sequential reads and writes, it doesn't provide accurate real world results but i figured it should show best case performance. I followed up with Anvil Pro to simulate real(ish) world performance and it seems to confirm the the results.

Level-2 cache (MBU or LBW) is only used when I exceed the Level-1 cache. So for my setup if I don't have Defer write enabled, write speed is terrible because writes are being passed directly to the HDD Storage space which has that RAID5 (like) write penalty. So write speed only become usable when I turn defer write on. There are some things that I can use this with no problem but I can't see using this with a Virtual machine or a database as they could get corrupted if there is a power loss.

What I had hoped to do was:
- Use the RAM act as a fast read cache, only using it as a write cache for transient data that won't cause any issue if lost (such as a pagefile, or temporary database)
- Use the SSDs to cache frequently accessed reads (level 1 & 2) that are not popular enough to be held in RAM and use as a write cache for all writes. Passing all writes directly through to the SDD stripe set which would then be synchronized to the the HDDs (at their slower transfer rate) for slow storage and parity.
- Use the HDDs for high capacity, slow storage. The HDDs are where I can provide redundancy more economically, if the SSDs are intercepting the writes first, then I don't have to be concerned with the extra overhead that parity or 3x mirroring adds to the write speed.

I've also made some observations on how RAM write caching performs and I had hoped to see a little more of a linear scale up on RAM writes. The read speeds seem to scale nicely but the write speeds seem to take a hit which worsens the smaller the block size I use. I was able to witness this scaling performance on my older and my newest machine (i7-970 & i7-3930k). When I run the same benchmark on just the SSDs everything scales up perfectly until read speed falls off a cliff on 8192k reads.

I'm going to include some of my results so you can visualize what ATTO is reporting. Looks like the forum software only allows one uploaded image at time.

8xSSDs Simple (raid 0)
8xSSD-Thin-Simple-NTFS.png
8xSSD-Thin-Simple-NTFS.png (19.82 KiB) Viewed 8375 times
Last edited by dustyny on Sun Sep 02, 2012 3:22 pm, edited 1 time in total.
dustyny
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Re: Works in Win2012 (w stor spaces) but I have some questio

Post by dustyny »

8xHDD thin with parity (Raid 5)
8xHDD thin with parity (Raid 5)
8xHDD thin with parity (Raid 5)
8xHDD-Thin-Parity-NTFS.png (19.04 KiB) Viewed 8374 times
dustyny
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Re: Works in Win2012 (w stor spaces) but I have some questio

Post by dustyny »

8xHDD Read/Write Caching, Block size 512KB, Level 1 Cache 20,000MB, LFU-R, Write Defer 60 secs, Overcome C1, Level 2 Cache 500,000MB, MBU
8xSSD-Thin-Simple-8xHDD-Thin-Parity-Fancycache-RW-Defer-60-Block-512KB-LFUR-Cache-2000-C1-L2_Cache-500000-MBU.png
8xSSD-Thin-Simple-8xHDD-Thin-Parity-Fancycache-RW-Defer-60-Block-512KB-LFUR-Cache-2000-C1-L2_Cache-500000-MBU.png (20.2 KiB) Viewed 8374 times
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Re: Works in Win2012 (w stor spaces) but I have some questio

Post by Support »

Hi dustyny,

Thank you very much for your kind feedback!
Actually we're improving FancyCache for better performance and features. I hope the next version will become a great one.
dustyny
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Re: Works in Win2012 (w stor spaces) but I have some questio

Post by dustyny »

My pleasure. I think you guys have a great piece of software and you're one of the very few companies who hasn't been tied up in an exclusive deal with a drive manufacturer. I'll be keeping a close eye on the progress of this project and I'm curious to see what it evolves in to. :D
turkina
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Re: Works in Win2012 (w stor spaces) but I have some questio

Post by turkina »

This is very similar to what I'll be running soon.

Windows 2012
2x240GB Intel 330 SSD for caching
8x2TB Seagate 7200RPM data disks

I plan on mirroring the SSDs and using them as read/write cache for the 2TB drives. The host itself has 32GB of RAM which will also be used for read caching. Being someone who works with EMC SANs and FAST Cache, I'm eager to see the results.
dustyny
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Re: Works in Win2012 (w stor spaces) but I have some questio

Post by dustyny »

To be honest you might not see that big of a gain using just 2 SSDs, those 8 hard drives should be able to read/write faster then the 2 SSDs. You should do some testing but my guess is your real gain will come from the RAM caching and you'll probably lose some speed when you hit your SSD cache.

Recently I dropped my HDDs out of the set and I've just been using the Ram caching and the SSDs. Level caching wasn't working as fast as I had hoped (beta software) so I figured I'd come back to testing the HDDs behind the SSDs after a new revision comes out. There seems to be some sort of RAM issue but I think it's been discussed and hopefully will be fixed soon :D

All in all I think the software was tremendous potential, they just have to sort out a few things first. Definitely not ready for a production environment just yet but great for the lab.

My advice (for now) is use the SSDs in a mirror to host the OS and use the 4 HDDs in RAID 10. Create two Simple storage spaces and then mirror them under disk manager, give the drive 20-25GB ram (RAM use will probably exceed what you assign).
turkina
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Re: Works in Win2012 (w stor spaces) but I have some questio

Post by turkina »

I do see a noticeable improvement, specifically with any parity vdisks I create.

However, my biggest concern is the memory leak in FancyCache. I just noticed my server was at 98% memory utilization despite only configuring a total of 8GB out of 32GB for L1 cache. After disabling and re-enabling cache on the two vdisks I went back to 31% memory utilization.
dustyny
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Re: Works in Win2012 (w stor spaces) but I have some questio

Post by dustyny »

Well something to keep in mind, Lvl 2 cache only starts to be used if Lvl 1 fills up, so check your performance stats for that drive. You might not even be using your SSDs if you aren't moving a lot of data around. I rarely utilize Lvl 2 caching, even when I'm running a bunch of Hyper-V VMs it rarely hits the Lvl2.

As for the memory leak, it's been reported and acknowledged by the devs hopefully they'll have a fix in a new build. It's odd but even with maxed out RAM my Win2012 box is responsive and rock solid.

I'm hoping they get a new build out soon but coding takes time. IMO Romex has a great product that even in beta easily competes with competing products that are very expensive.

I'm going to use it in the lab and hopefully by the time I'm ready to launch a real test pilot they'll have some of the bigger issues worked out. :D
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