nuitlejour

Does LSI cachevault speed up intensivity I/O?

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Hello, everybody

I bought a second-hand LSI 9270CV-8i, it has built-in cachevault feature that offers safer cache protection with flash (not memory) and capacitor (not battery).

I was wondering, besides it is more secure, is cachevault able to speed up small files I/O like cachecade technology? since both have flash as additional data pool.

I searched the web, there is no material saying that cachevault would speed up I/O, except this murky line:"CacheCade and LSI CacheVault Flash Cache can be combined.
" from this site: http://www.thomas-krenn.com/en/wiki/LSI_MegaRAID_CacheCade_SSD_Cache

If it does, I will be able to save additional money to buy slc ssd for cachecade.

Can anyone share some insight?

Thanks a bunch!

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The purpose of cache vault is to replace the battery model with something that can last longer due to the flash memory and capacitor. It is not accessible to the card or the volumes on the card for use as a cache. The capacitor allows the card to keep the data that was sitting in the card cache ram viable in a crash and can write it out to disks when power is restored.

I think that any amount of cachecade wild be nice even if it were mlc. It helps buffer more read/write at faster seeks.

Just checking, did you get all the pieces? I think the cachevault is on the card but the caps are on a second card and cable. I think that is how my 9271 is.

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The purpose of cache vault is to replace the battery model with something that can last longer due to the flash memory and capacitor. It is not accessible to the card or the volumes on the card for use as a cache. The capacitor allows the card to keep the data that was sitting in the card cache ram viable in a crash and can write it out to disks when power is restored.

I think that any amount of cachecade wild be nice even if it were mlc. It helps buffer more read/write at faster seeks.

Just checking, did you get all the pieces? I think the cachevault is on the card but the caps are on a second card and cable. I think that is how my 9271 is.

Thank you!

"It is not accessible to the card or the volumes on the card for use as a cache." it makes sense.

and thank you for the tip, I did get all the pieces, including the cap.

The reason that I bought 9270cv was my old 9260 was unstable for some reason, in MSM it gave "unexpected sense at address 0x....", and some disk went offline starting rebuild.

At first I suspected it broke. After mounting 9270cv, the warning message disapeared, but I did find that temperature of main chip was ridiculously high (96C, 204F).

Maybe my old 9260 didn‘t break after all, maybe it's just overheating.

I'll keep my case open for now, and wait for the mini fan I bought.

Thank you for the tip:"I think that any amount of cachecade wild be nice even if it were mlc. It helps buffer more read/write at faster seeks."

I'll post performance result when I buy ssd for cachecade.

Edited by nuitlejour

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Unexpected sense errors happen for many reasons, not necessarily card. It can be due to a drive dropping, bad enclosure, bad cabling, or anything. I an working on diagnosing some right now that I think is related to enclosure issues. If you are using a breakout cable, try swapping ports. Likewise with an enclosure. If the problems stay on the same port, could be cable. If they move, probably drive. It can definitely be an overheat though. I wouldn't say it is necessarily the card though. Drives are pretty high.

Are you using Linux? I have been some testing techniques there if you'd like to try. Not near my PC or I'd write more. :)

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Unexpected sense errors happen for many reasons, not necessarily card. It can be due to a drive dropping, bad enclosure, bad cabling, or anything. I an working on diagnosing some right now that I think is related to enclosure issues. If you are using a breakout cable, try swapping ports. Likewise with an enclosure. If the problems stay on the same port, could be cable. If they move, probably drive. It can definitely be an overheat though. I wouldn't say it is necessarily the card though. Drives are pretty high.

Are you using Linux? I have been some testing techniques there if you'd like to try. Not near my PC or I'd write more. :)

Thanks for the tip, I am using windows right now, and raid is for remote sensing data storage.

I think cable swapping would be a fantastic idea, I'll try it first.

I checked the temperature on my disks, they are not high (~ 40 C), so I don't think that's the issue.

The "unexpected sense " warning always appears at one certain port, I think it's either the cable or the disk at brink of breaking down.

Thanks again!!

Have a lovely day !

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Unexpected sense errors happen for many reasons, not necessarily card. It can be due to a drive dropping, bad enclosure, bad cabling, or anything. I an working on diagnosing some right now that I think is related to enclosure issues. If you are using a breakout cable, try swapping ports. Likewise with an enclosure. If the problems stay on the same port, could be cable. If they move, probably drive. It can definitely be an overheat though. I wouldn't say it is necessarily the card though. Drives are pretty high.

Are you using Linux? I have been some testing techniques there if you'd like to try. Not near my PC or I'd write more. :)

Here is my performance test, without and with cachecade, there is a significant boost of 512K and 4K queued 32 read , I am fairly happy with this result.

my raid configuration:

post-102498-0-51581000-1405942855_thumb.

without cachecade:

post-102498-0-98348900-1405942865_thumb.

with cachecade:

post-102498-0-72181700-1405942876_thumb.

Edited by nuitlejour

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Nice, it can also do write cache if you can shove in a second drive. CC will drop back to read-cache only if one of the two drives in the mirror fails.

Sent from my Nexus 7 using Tapatalk

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Nice, it can also do write cache if you can shove in a second drive. CC will drop back to read-cache only if one of the two drives in the mirror fails.

Sent from my Nexus 7 using Tapatalk

Keen observation, I tried the CC 2.0 Pro soft trial key, I was wondering why CC is read only!!

You answered my question before it is asked!!

You are my hero of the day!

Edited by nuitlejour

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Nice, it can also do write cache if you can shove in a second drive. CC will drop back to read-cache only if one of the two drives in the mirror fails.

Sent from my Nexus 7 using Tapatalk

I don't know what's going on here.

I changed CacheCade Virtual Drive (one ssd, raid 0) to Write Back, there is significant drop in seq read/write, 512K read, etc.

Only noticeble improvement was 4K read.

post-102498-0-94768700-1406273681_thumb.

post-102498-0-53333900-1406273695_thumb.

post-102498-0-71589300-1406273709_thumb.

Did I do something wrong? Do I need to buy another ssd to build raid 1 virtual CacheCade drive for the benefit of REAL cached write?

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Keen observation, I tried the CC 2.0 Pro soft trial key, I was wondering why CC is read only!!

You answered my question before it is asked!!

You are my hero of the day!

Finally, I think I know what's going on.

Changing "test size" in Crystal Disk Mark from 4000M to 50M, gives higher score. Maybe it's because 4000M is too big for CacheCache to manage.

Anyway, I bought a second ssd, created raid 1 for CacheCade, enabled WriteBack, here is the test result:

post-102498-0-22691800-1406890950_thumb.

Edited by nuitlejour

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