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HW RAID 1 vs SW RAID 1 vs incremental backup


Tomcat76

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I have purchased most components for my "new" Windows 7 machine.  It will serve as video editing workstation and contain backups from other PC's in the network.  I already have three 4TB hard drives that contain such backups, but they are "standalone" drives.  I now intend to buy two 10TB Western Digital Red drives for the task and I would like both to contain the same data.
 
What I find important: should one drive fail, the data on the good drive should still be accessible (should continue to work as standalone drive); it should also be straight forward to rebuild the previous setup after replacing the bad hard drive.  Because the RAID will only be used to store a backup on, speed is a non-issue.
 
Since I have never dealt with RAID before, I have read many things on the subject online in the last couple of days, but I'm still having difficulties deciding which way to go.  These seem to be the choices:
- hardware RAID (dedicated PCIe RAID controller)
- "motherboard" RAID
- Windows mirror
- clone, followed by periodic incremental backup
 
System specs:
Windows 7 Professional 64-bit
Asus X99-E (10 Intel SATA ports of which 6 can use RAID)
Intel i7-6850K
16GB RAM (4x4)
 
I will not be using RAID on the system drive or on the main data drive in that PC.  Only the backup drive should be mirrored.

From what I understand, it can prove difficult to rebuild a broken hardware or MB (fake) RAID, while drives once belonging to a Windows mirror can be reused independently.  Is this correct?
The incremental backup method seems a little over the top as it would be backing up a backup (in my scenario).  Any backup should be written to both destination drives simultaneously.
 
Any thoughts?

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In the first instance are you talking about a RAID array (mirror / Raid 1) for your data that would be internal or external ie USB?

I am not hugely knowledgeable on RAID but I never raided internal HDDs simply because if one drive gets an error, virus, etc it will copy it to the other drive. 

For me, at least, the safest way to use RAID1 ie one drive mirroring the other, is to use it in an external USB RAID enclosure. Which is what I did.

My pc has 3 internal HDDs. An SSD for dual boot and 2x 2TB HDD for data. The 2 internal data drives are standalone drives ie no raid of any sort. I save all my data to HDD1 and then periodically use Syncback to synchronise the data from HDD1 to HDD2.

I very recently purchased an external USB3 Raid enclosure capable of holding two HDD and have set this up in Raid1 array ie mirroring. Every couple of weeks, I connect the External USB3 RAID enclosure to my pc and synchronise it with HDD1.

I know that many users will say that this is a lot of trouble but I prefer it as it is the safest way, imo, to keep my data safe.

The external enclosure I went for was an ICYBOX one (IB-RD3620SU3) is of type HW RAID 1 ie hardware. I found USB3 speeds to be good (limitation on small files) and get speeds with 7200 drives of 100-125MB/s. Copies a single large 5GB file in just over a min.

If one of the drives in the external RAID goes bad, simply pull it out replace it with a good drive and the software to the ICYBOX will rebuilt the array ie it copies over the data from the good drive to the new drive. You can also just pull out any of the 2 drives in the RAID enclosure and just install it internally your data will be accessible.  

Good Luck with it.

 

Edited by risk_reversal
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12 hours ago, Tomcat76 said:

From what I understand, it can prove difficult to rebuild a broken hardware or MB (fake) RAID, while drives once belonging to a Windows mirror can be reused independently.  Is this correct?

Yes. If your hardware or MB RAID controller fail, and you don't have identical substitute, returning your data may be tricky (but possible in most of the cases). In contrast, windows-mirrored data disks may be easily transferred to any other windows-based system, despite hardware difference. So, if the I/O speed isn't a limiting factor for you, the software mirror is the better solution.

Edited by Yellow Horror
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I agree that an external backup is the safest, but I intend to have some of the backup processes automated.  I also like to keep the clutter to a minimum.  The original plan was to have a dedicated PC or NAS for backups, possibly even running a flavor of Linux, but since I won't be video editing 24/7 (actually < 50% of the time) I thought about combining the two functions into one PC.
 
I'm gonna go with a Windows mirror.  Thanks for the help, guys :thumbup

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Just another thing you need to know about Windows software mirrors: don't try to make more than one mirror volume at one pair of physical disks. Despite Windows disk management allows this, it has a serious design flaw: after a power failure or any other not scheduled system stop, it resynchronize all software-RAID volumes at once instead of one-after-another basis. If two or more soft-RAID volumes share a physical drive, the drive has a very hard work chasing its heads back and forth for many hours.

Edited by Yellow Horror
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You can use onboard RAID if you want but the controller would need to support JBOD+RAID. Because you say you want to use RAID1 for data and your other disk wouldn't. So in a RAID scenario, you'd have your OS on JBOD and the other two on the array. Not all controllers on retail boards can do this. And, to make matters worse, this information is not usually in the manual. You'd have to test it to see if you could add a single JBOD disk in addition to the RAID1, and still be able to boot on the JBOD.

If you can't run in this scenario, then you should use a controller card for the array and leave your board on AHCI. If you are going to install Windows using Windows Setup (DVD install), I recommend that the RAID card or the disks are not connected until after the OS is installed.

If you are going to go with a RAID setup, it is recommended that you purchase your replacement disks at the same time as the main ones. When a disk fails, you order a replacement for the replacement. The idea then is you have your spare disks (whatever the fail maximum is) ready and waiting. For a RAID1 I would say 2 disks. So to properly prepare for a RAID1 in your scenario would be to buy 4x 10TB disks, 2 for your array and the 2 replacements you keep on hand.

You should not use the system when the RAID is in degraded or rebuilding. Using the system in this state, especially when you have lost half of your failsafe (1 disk in a RAID1, 2 in a 5, etc) is risky, and even if not in rebuild, data transfer in either direction, or the entire OS itself may become very slow. If you have the replacement disk available immediately at the time of failure, you will be able to maximize your uptime rather than having to wait for a replacement to come in the mail.

I have never liked Windows mirror, but that is probably because of my experience with desktop and enterprise RAID controllers.

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There is no problem with JBOD+RAID config as long as a RAID controller is an extension board. Just connect your system drive to MB SATA port and go on. In case of on-board RAID controller, yes, you need to check if it allow such a config.

I think, there is no need to purchase 2 spare disks in advance for a mirror in home usage. In most scenarios, if you experience 2 drive failures at once or in a short time, you already lost part or all of your data, and the second spare disk on hand can't prevent this. Rebuilding of a 10 Tb volume on a low-cost system may take days, so you may purchase another spare disk before it ends.

Also, you definitely may use your RAID volume while it is rebuilding, if you need to. But it is highly recommended to not use it heavily, because this slows down rebuilding and so delay the time when your data will be "in safe" again.

Edited by Yellow Horror
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The Asus X99-E has 6 Intel SATA ports that can be set to RAID and 4 that can't, so it should be able to handle a JBOD+RAID mix.
 
But I think a hardware RAID or onboard RAID setup is overkill for me.  A Windows mirror would already give me three copies of most files (the original, the main backup and the mirrored backup), I can still access the backup data if one disk fails without the need to rebuild (I'm not forced to buy another hard drive or have spare ones at hand) and it's less picky about firmwares and stuff.  It's basically secure enough for my needs, and cheaper.
 
The only thing I'm really worried about is the requirement to convert to dynamic disks.  Many years ago, I was taught to always stick to basic disks because of possible issues regarding data integrity with dynamic disks.  It was the Windows 2000 era, though.

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On 11/15/2018 at 3:53 PM, Tripredacus said:

RAID is not a backup solution, never equate the two.

I know, but thanks for pointing that out.  In any case, I want the backup to be RAIDed, not the original.

Edited by Tomcat76
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On 11/15/2018 at 1:20 AM, Tomcat76 said:

The only thing I'm really worried about is the requirement to convert to dynamic disks.  Many years ago, I was taught to always stick to basic disks because of possible issues regarding data integrity with dynamic disks.  It was the Windows 2000 era, though.

The Win2k had a major issue of keeping the configuration data of dynamic disks group in the system registry only. So a system crash meant that you can't access your data without a third-party recovery tool. Since XP, the configuration data is stored on each disk of the group, and in more than one copy. So, the dynamic disks are now safe enough.

On 11/15/2018 at 1:20 AM, Tomcat76 said:

A Windows mirror would already give me three copies of most files (the original, the main backup and the mirrored backup)

Don't forget that "two" copy on a mirrored volume should be considered as "one" against any disaster that don't boil down to a disk failure. Malware, misuse, garbage data in the backup software data buffer by a high-energy space particle, or one of millions of other possible issues destroys both of mirrored copies at once.

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15 hours ago, Yellow Horror said:

The Win2k had a major issue of keeping the configuration data of dynamic disks group in the system registry only.

All these years I thought that Dynamic Disks data were written to disk in 2000 as well, AFAIK they were introduced in Windows 2000 and while XP may have bettered the management of them there are not any registry vs. on-disk differences:

https://www.z-a-recovery.com/articles/dynamic-disks.aspx

I may remember it wrongly, of course, have you got any sources about your statement?

jaclaz

 

Edited by jaclaz
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10 hours ago, jaclaz said:

I may remember it wrongly, of course, have you got any sources about your statement?

No. You are right, and my memory is failing me. Not Win2k, but NT 4 was the system that store grouped disks (named "multidisks", not "dynamic disks" at the time) configuration in the registry only.

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I personally use Dynamic Disks Raid 5 on my main home PC running XP (patched to support such a config) for about 10 years. During this time, i experienced two disk failures and some preventive disk replacements due to bad SMART reports, all times without any data losses. I also experienced the disk group breakage one time due to my own fault in using a third-party disk management tool. I was able to recover all my data by properly use of another piece of third-party software.

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Yep, I used them (Dinamic Disks) "extensively" on Windows 2000 in "mirroring" mode, aka pseudo RAID 1 (much less on XP - a small hack was needed on some system files to have them working) and never had particular issues.

Over the years however I have seen quite a few people recovering from "mysterious" issues with "normal" disks.

More than a few times, for *some reasons*, the 0x07 Partition ID of "normal" NTFS primary volumes (system and boot volume)  *somehow* was changed to 0x42, and the disk volume became unreadable/the system couldn't boot.

A direct disk edit to 0x07 solved the issue just fine.

A similar example:

http://reboot.pro/topic/3463-converting-a-dynamic-disk-back-to-a-basic-disk/

Of course if the disk was actually Dynamic you should also delete the info at the end of the disk.

Or use TESTDISK:

https://mypkb.wordpress.com/2007/03/28/how-to-non-destructively-convert-dynamic-disks-to-basic-disks/

Please note how the good MS guys want you to delete the contents to perform a conversion form Dynamic to Basic:

https://docs.microsoft.com/en-us/windows-server/storage/disk-management/change-a-dynamic-disk-back-to-a-basic-disk

I never found a suitable explanation for this and MS lists (listed) only the opposite case (Dynamic Disks being *somehow* reverted to basic or "mixed mode"):

https://web.archive.org/web/20080327141814/http://support.microsoft.com/kb/236086

https://support.microsoft.com/en-sg/help/320283/you-cannot-revert-a-disk-to-a-basic-disk-if-the-disk-appears-as-dynami

jaclaz

 

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