Friday, November 18th 2011

Intel Making TRIM on RAID Possible?

The TRIM command feature has become an industry standard for internal garbage collection on SSDs. Unlike with magnetic storage devices such as hard drives, in NAND flash storage devices, new data can't simply be overwritten on existing deleted data (like overwriting on cassette tapes), instead NAND flash cells are first put through erase cycles, and then fresh data is written on them. This leads to degradation of performance in SSDs, as all deleted data will be put through erase cycles. The TRIM command allows the drive to tag freshly deleted data for disposal, and then erase flash memory occupied by that data when idling, and dynamically allocating erased cells for fresh data. This dramatically reduces write performance degradation of SSDs. Unfortunately, issuing TRIM commands to SSDs that are part of a RAID volume is so far not possible, because the RAID volume acts as a sort of an abstraction layer between the OS and physical disks. Some low-level data about member disks can still be read by diagnostic tools, but that's about it.

If the Release Notes document of Intel Rapid Storage Technology (RST) driver 11.5.0.1109 Alpha (read here) is to be believed, Intel plans to bring TRIM support to RAID 0 volumes with a future version of RST. Snooping through the document, one can find the following line:
2. This release will not enable the TRIM on RAID0 feature, but it will be added in the next RST 11.5 release. Contact your RST AE representative with questions.
Source: StorageReview
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14 Comments on Intel Making TRIM on RAID Possible?

#1
95Viper
Interesting... Thanks BTA.:)
This, if done, may open up other possibilities.
Waiting to see results from this.
Posted on Reply
#3
ironwolf
Yay, so no longer a question of IF but of WHEN.
Posted on Reply
#4
Bundy
This is the good news, thanks.
Posted on Reply
#5
Fx
awesome news
Posted on Reply
#7
Wile E
Power User
Now if they would only allow the use of port multipliers.
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#8
TheGuruStud
Can't you just use a defrag app for trim, though?
Posted on Reply
#9
FreedomEclipse
~Technological Technocrat~
by: TheGuruStud
Can't you just use a defrag app for trim, though?
Only if you want to kill or shorten the lifespan significantly of your SSD
Posted on Reply
#10
TheGuruStud
by: FreedomEclipse
Only if you want to kill or shorten the lifespan significantly of your SSD
I mean using the app to enable trim. But I just looked it up and it does not work when on a raid controller. Looks like everyone dropped the ball when they developed TRIM. It's not like raids are anything new.
Posted on Reply
#11
lauri_hoefs
by: TheGuruStud
I mean using the app to enable trim. But I just looked it up and it does not work when on a raid controller. Looks like everyone dropped the ball when they developed TRIM. It's not like raids are anything new.
No, it's nothing new. But that is not the problem.

The problem lies in the way RAID works: it is transparent to the OS. For the OS the RAID array is just an I/O address space. Data gets sent or requested to and from those addresses. The RAID controller then splits, mirrors, calculates parity info, or whatever is needed to move the data from and to the individual disks. But the OS is not directly connected to this process, it does not "see" the disks directly, only the array. This way the OS is not even aware, that TRIM capable devices are present. And there has been no easy and reliable way to pass the TRIM command over the RAID controller.

Though it seems that Intel has come up with a way to do just that.:respect:
Posted on Reply
#12
VulkanBros
Hmmm...sounds interesting, and correct me if I am wrong, BUT RST ony works on Intel chips and drives.....

You can still use the manual way with tools like as-cleaner...but of course native support for all would be better.....
Posted on Reply
#13
FreedomEclipse
~Technological Technocrat~
by: VulkanBros
Hmmm...sounds interesting, and correct me if I am wrong, BUT RST ony works on Intel chips and drives.....
Wrong. You dont need an intel drive to use RST, you do however require a Z68 Chipset. Any SSD will do. your performance gain is based on how good the SSD is
Posted on Reply
#14
btarunr
Editor & Senior Moderator
by: FreedomEclipse
Wrong. You dont need an intel drive to use RST, you do however require a Z68 Chipset. Any SSD will do. your performance gain is based on how good the SSD is
Semi-wrong. RST supports any recent Intel ICH#R southbridge or PCH.
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