SSD RAID Maintenance Toolset: How to backup and restore RAID-0 image

I have two Intel 40GB SSDs in RAID-0 using Intel's on-board RAID (P67 chipset). Given the lack of Trim support, I have been thinking of periodically re-imaging the SSDs. i.e.
1. Create a file-system aware image of the RAID volume on the SSDs
2. Do a Secure Erase of the SSDs
3. Restore the image back on the SSD

The requirements are:
1. The SSDs are in a boot-able RAID array, and are the primary boot disk.
2. The image of the RAID volume should be file-system aware, to take care of TRIM issues (i.e. not copy dead files when creating the image).
3. The restore should create a new image which is equivalent to the disk image seen by the file-system and also bootable.


Questions:
A. I presume I will have to make the system a dual-boot system. The primary boot partition being the SSD array, and a secondary boot partition which I will use to do the backup/secure-erase/restore.

B. What would be the most appropriate way of performing the file-system aware back-up of the SSD RAID volume? Which software to use? I prefer free/open-source software since this is a once a quarter exercise.

C. Is there any way to script this:

0. Change boot partition to the back-up partition
1. Boot into back-up partition
2. Create file-system aware image of the RAID-0 volume
3. Go-back to the BIOS at this point and remove the RAID volume to allow the Intel SSD toolbox to secure-erase).
4. Boot back into back-up partition
5. Perform Secure-Erase of the two individual SSDs.
6. Go back to BIOS and recreate the RAID volume on the SSD
7. Boot back into the back-up partition
8. Restore Image from the file-system aware backup created in Step #2
9. Change boot partition back to the primary RAID volume

I can confirm that Acronis True Image Home 2011 comes with a disk and partition backup that supports SSD but I am not sure if RAID does not complicates things a bit. I am also interested in the best way of doing this, anybody?

dxter486 said:

I can confirm that Acronis True Image Home 2011 comes with a disk and partition backup that supports SSD but I am not sure if RAID does not complicates things a bit. I am also interested in the best way of doing this, anybody?

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Yeah acronis is your best bet and no raid does not make thing hard to do you just copy the image to your back up drive and then re image back to the correct ssd's and your raid array should be back.

Granted its not free but they give you 30 days full access trial.

Clonezilla might be able to copy to the backup volume. Might be worth a shot.

I have been using this system for almost six months now. Recently ran the SandraLite benchmark on the RAID-0 array, and am getting close to 2x Write Speed of individual drives (about 30-35Mbs/each). It seems that Intel's controllers are rock-solid so no write amplification so far.

I configured the 2 x 40GB array into a 64GB volume leaving the rest free. According to the AnandTech article this leaves enough space for the controller to work with. Currently have about 40GB on this volume, 25GB of which is Windows.

Use my 4-disk RAID volume for non-core programs, and data-storage needs.

So far I have not felt the need to secure erase and re-install the image.

the only time you should ever secure erase your drive is when you fill it, delete everything, and want to start over.

you won't gain any performance by taking a 50% full raid array, secure erasing the drives, and then plopping the same amount of data onto those drives once again.

the drop in quality is very harsh on ssds. hitting 50% full will net you the near level of quality as 75% or higher full. unless you're starting over, there's no reason to secure erase, you'll just dirty the drives the second you throw back on the image.

that said, if you use linux, you can use ntfsclone to make an image of an ntfs partition and restore it with ntfsclone --restore. the above solutions are much more friendly though.

I configured the 2 x 40GB array into a 64GB volume leaving the rest free.

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AFAIK, for this trick to work as intended the extra space must be in a unformatted partition (Raw). Least that's what made my 2x80GB G2 RAID0 array work the best.

AAR, Acronis works great on RAID0 arrays.

While a Secure Erase will make your drives "brand new" and screaming that will only last a short time and the performance will return to "steady state" (normal levels).

Intel's performance doesn't have a major decrease and a Secure Erase will be a very short term performance increase and not worth the effort.

The nice (useless, but nice) thing with what the OP is suggesting is that when you open a defrag software after it, you can see your SSD all nicely defragmented.

It took quite a bit of effort (updating drivers and what not to get the build running) so I do not remember how exactly I created the volumes, but I think I created that using the Intel utility before installing anything. I created one volume (64GB) then the remaining portion I presume will be in the RAW format. Or do you have to explicitly do something to keep the space raw. When I bring up the Intel IRST console, I just see the 64GB array and no other partition in that volume; similarly the initial Intel BIOS does not show any other volume on the array.

I ran the tests to see if I need to do the secure-erase and re-image but I do not. I guess the key is to keep the enough extra space available for the controller to do its magic. And that the OS does not create enough new temporary files for it to be an issue. If the same file is be reused then even if it is deleted repeatedly the SSD should not be adversely affected with garbage files.

One thing which I did not understand is why the re-imaging will not help. The crux of the problem was that with the lack of TRIM pass-through, files created by the OS which are subsequently deleted still exist on the RAID array as used space since the TRIM command is not passed through. As a result even though the File System may show a lot of space available since it reclaims the deleted files, the SSD controllers may not realize that the file is no longer in use and the physical SSD space can be reclaimed.

When you do a file-system aware re-image, all the deleted files will be no longer be copied back. Essentially you are TRIMing the SSD (or doing garbage-collection on deleted files) by doing a secure-erase and recopy of the image which being file-system aware, does not have the deleted files.

So where did I go wrong?

I created one volume (64GB) then the remaining portion I presume will be in the RAW format.

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The idea is to remove 10-20% from the OS's "view" so it assumes that space isn't part of it's normal working (AKA formatted) area.

Some don't think the RAW vs formatted partition makes a difference, some do.

Naturally SSDs work much better when kept 50% full because extra space is needed but just another factor you could bring into the equation.

Read this informative thread and it may shed a little more light on the subject.

You hafta remember that this "Free Space" thing was started when there was no TRIM and larger SSDs were uber expensive.

With the current pricing I suggest taking the size of the OS/programs and doubling it to get the correct size. Stuffing 80-90GB into a 100GB drive is asking for low speeds.

One thing which I did not understand is why the re-imaging will not help.

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I'm lost.

The idea behind a Secure Erase is that it

An alternative method (faster) is to use a tool to perform a SECURE ERASE command on the drive. This command will release all of the user LBA locations internally in the drive and result in all of the NAND locations being reset to an erased state. This is equivalent to resetting the drive to the factory shipped condition, and will provide the optimum performance.

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An image will not re-set the required locations.

Read more about using an SSD/Secure Erase command.

Old Hippie said:

I'm lost.

The idea behind a Secure Erase is that it

An image will not re-set the required locations.

Read more about using an SSD/Secure Erase command.

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Dear Hippie:

The context here is to re-image, AFTER, a secure-erase. So a secure-erase refreshes the SSD. The re-imaging gets rid of all the un-TRIMed data so there is no garbage marked as used blocks on the disk; this is essentially another way of doing garbage collection. I also wonder that with 50% of the disk used, whether going through this cycle, will help in wear leveling. Will the drive controller now use the formerly unused space and help in wear leveling?

Also my Array shows the two 37GB drives and the 64GB volume with 10796MB as available space in IRST Console. I presume this means that this is unused space (Raw).

Anyway, since SiSoft did not show any degradation in write speed I am not going to do anything. Using about 40GB of the space, and it is unlikely to grow.

The context here is to re-image

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Your use of "re-image" was confusing to me.

I guess you're just applying an image of your OS after you Secure Erase a drive which is what most do.

Any type of free space will help but AFAIK a separate partition in RAW format will hold that space for the drive itself.

Also my Array shows the two 37GB drives and the 64GB volume with 10796MB as available space in IRST Console. I presume this means that this is unused space (Raw).

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It can't be RAW because you couldn't use it.

You should be just fine using 50% of the drive's space.

Actually I have done absolutely nothing. I had put up the post while planning the setup. I thought that it was worth revisiting the performance and I did not see anything significant enough for me to go through the pain.

As you said with sufficient over provisioning, these RAID-0s work fine.

As you said with sufficient over provisioning, these RAID-0s work fine.

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Usually the term 'over-provisioning' refers to the drive's internal provisioning requirements and isn't counted as part of the drives actual usable space but leaving plenty of free space is definately recommened and does wonders for an SSDs performance.

I've run RAID0 since my first Intel G1s and haven't had a problem not using TRIM.

Good Luck!

So OVER - (over-provisioning...)

I think the price difference has come down enough not to worry about it anymore. Further since higher capacity drives essentially are a combo of multiple smaller (but often shared controller), the performance difference for small reads/writes should not be that different between two small drives in RAID-0 and one big one.

So OVER - (over-provisioning...)

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LOL!

I suppose but I'll leave it up to you to explain what it is when free space should be standard in any SSD aficionado's vocabulary.

Further since higher capacity drives essentially are a combo of multiple smaller (but often shared controller), the performance difference for small reads/writes should not be that different between two small drives in RAID-0 and one big one.

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That hasn't been my experience but you're more than welcome to think what you want.

Old Hippie said:

LOL!

I suppose but I'll leave it up to you to explain what it is when free space should be standard in any SSD aficionado's vocabulary.


That hasn't been my experience but you're more than welcome to think what you want.

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Care to elaborate? So a RAID-0 of 2 Intel 40GBs is better than an 80GB for small read/writes? I noticed the specs show the write speed scaling with size but read speed tends to throttle. What happens in the real world?

Care to elaborate? So a RAID-0 of 2 Intel 40GBs is better than an 80GB for small read/writes?

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My experience has been that most aspects scale really well and even if two aspects are improved it'd be worth it to me.

I haven't looked at those little Intel drives because smaller usually means slower in the first place and I would never attempt to run W7 on a 40GB disc.

AAR, if you're thinking 2x40GB units or 1x80GB unit I'd probably look at my computer's usage, decide if I knew enough about RAID to feel comfortable using it and realize that it's stupid to run RAID without back-ups or........toss a coin.

There's no disputing if these drives perform better in RAID because they do.

The only problem is the operator's expertise with the care and feeding of a RAID array.

EDIT....All this RAID stuff is referring to RAID0 but I shouldn't have to tell anyone..........

Ran Crystal Disk tonight while the WS was still in use (light use).


The disk are rated
Sustained Sequential Read up to 170MB/s
Sustained Sequential Write up to 35MB/s

So max theoretical is 340/70.

What do you make out of the results? In another run on the 4K Random I got (20.40/53.32). That random read performance on the 4K without the deep queue is kind of low and scary.

Is the W7 built in backup a suitable image maker? I have mine create a daily backup, and I've restored it to the SSD RAID-0 a couple of times now. I use a a pair M4 128Gb for the array, and as the garbage collection on these drives is said to very good I don't worry about lack of TRIM.

The main question I wanted to ask is what you think about the built in image maker?

btb said:

Is the W7 built in backup a suitable image maker? I have mine create a daily backup, and I've restored it to the SSD RAID-0 a couple of times now. I use a a pair M4 128Gb for the array, and as the garbage collection on these drives is said to very good I don't worry about lack of TRIM.

The main question I wanted to ask is what you think about the built in image maker?

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I just used the Macrium Reflect to move from Intel V-25 40GBx2 to M4-64GBx2 array. The free stuff was good enough; even allowed me to create a dedicated Windows Deployment Kit based binary with the Macrium software built in to allow for image restore. I initially had stored the image on an external USB Drive but it wanted drivers for that. However I noticed it was reading my existing Intel based Hard Disk raid volume, so I did not even need the external drives.

Incidentally I initially tried to use IRST within Windows to go from one disk to two disk RAID0 but it gave a general software error. So had to go through a roundabout image based loop.

Nice improvements in sequential read speeds. But the random read speeds without a large QD was poor, just like the Intel V-25 based array.

.

aviat72 said:

I just used the Macrium Reflect to move from Intel V-25 40GBx2 to M4-64GBx2 array. The free stuff was good enough; even allowed me to create a dedicated Windows Deployment Kit based binary with the Macrium software built in to allow for image restore. I initially had stored the image on an external USB Drive but it wanted drivers for that. However I noticed it was reading my existing Intel based Hard Disk raid volume, so I did not even need the external drives.

Incidentally I initially tried to use IRST within Windows to go from one disk to two disk RAID0 but it gave a general software error. So had to go through a roundabout image based loop.

Nice improvements in sequential read speeds. But the random read speeds without a large QD was poor, just like the Intel V-25 based array.

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Fair enough, always more than one way to do things, and good we can choose. I like the built in image backup for the automatic daily incremental backups. I also double boot, so if the default restore method caused problems like you describe, it would be easy to mount the VHD image and clone/copy to a new partition.

Nice to have a backup of the OS in case of a cock-up can do a quick restore, though usually do a reinstall every so often anyway.

I have a reasonably complicated scheme using symlink to store stuff on the SSD vs Hard Disks.
When I do a backup using WIndows and ask for a system image it tries to use data from both the disks.
I was not sure how it would work out. Also for some reason the Windows rescue disk image I had was not being read properly.

The Reflect solution gave me complete control on what will be imaged, what would be restored and it automatically resizes partitions etc.

IIRC one problem with Windows backup is that it will not restore on a smaller disk even if the original disk data would fit in. But I have not tried that so can not say for sure.

Revisiting the 2x64GB M4s in RAID-0. These random read performance (4K) is quite poor. And even with a single drive it was not too great. Is it the onboard controller which is the problem?

aviat72 said:

Revisiting the 2x64GB M4s in RAID-0. These random read performance (4K) is quite poor. And even with a single drive it was not too great. Is it the onboard controller which is the problem?

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Seems the C4s sacrificed the all important (for me) random performance for a higher top speed.

This and the larger NAND size is exactly why I still have my C300s and why they still go for high prices on Ebay.