I have a friend who just had a disk crash on his server in his office.

 

He had daily backups going, and the backups are good, but they run at 1:AM and the server died around 11 PM, so he lost a days work, and some important stuff.  Restoring a number of software packages won't work after restore from backup however, due to installation issues regarding how they are licensed.

 

He had RAID-1 mirroring, and thought he'd be OK.  His IT guy goes in and breaks the mirror and.... nada.

 

Long story short, it appears the controller FUBAR'd the partition tables on BOTH drives in RAID-1.

 

I was able to recover his files, but he learned the hard way that mirrored drives don't give you 100% safety.

 

He asked me what's better.  Back in my Novell days, I'd suggest SFT III (duplexed servers with a MSL) but that's oldschool now.

 

Are there any current products that provide disk mirroring between 2 different servers with failover?  I don't mean WSFC where you have multiple servers that all reach into shared storage, but two different servers each with one disk in a RAID-1 mirror.

 

Another potential solution would be some type of realtime backup, where file changes are backed up to a different server each time a file is closed/modified.

 

Unfortunately, because of his industry, there are several mandatory software packages he uses that are Windows only and HAVE to be installed on a Windows server.

 

 

Any suggestions?

 

The first thing I did was make sure his OS was on a separate disk from his data.  I currently have him back up with a physically separate C and D drive, where C is for the OS, and a full disk image backup is made nightly.  So he can get a bootable system back up and running ASAP in a disaster.  That should handle the installation/licensing issues with his software.

 

Data is all on drive D but is still being backed up as files at night, so a day's work is still at risk.

While not the solution you need for this, I use a program called puresync to back up files.

This may help in the interim until you find what you are looking for.

It's not a full backup solution, it's more like a mirror/rsync type solution.

It may have some options that can help temporarily.

 

http://www.jumpingbytes.com/en/puresync.html

You are on the right track and asking the right questions. SFT III is/was a file server, great protection for data, not the application. This is where your separation of OS and data come in. You need different protection and recovery for the two datasets. SFT III would only protect the data portion. Luckily, there are many solutions in that space. Robust redundant file servers, now called NAS are not cheap.

 

Long story short, it appears the controller FUBAR'd the partition tables on BOTH drives in RAID-1.

 

I wont be so fast to say the controller did the corruption. The controller, doing RAID 1, should write the exact same to both drives. So if one is written incorrect, the other should too. Controllers know nothing of partition tables. Sounds like the problem was above the controller, but the outcome is the same.

 

Recovering from a controller failure is a nightmare, especially in the small business space. If you can locate an exactly matching controller, you may still face firmware versioning issues. Which version was running on the now dead controller? Small shops often never even knew. Even a RAID 1 drive from a controller may not be directly bootable without the controller. Controllers often shift the written blocks, shifting the partition table's location. The shift is to gain some space for drive signature or configuration data. After all, the disk is the controllers block device, and the controller is the OS's block device.

 

This is where we have all come to love/hate software raid. I know Windows software RAID has a few billion stories, but it does get that controller out of the middle. Keep It Simple... Booting Windows after a drive failure in a RAID 1 set is non trivial (at least to me), but the procedure is written and findable.

 

Two drives (4 if you want separate for OS), software RAID 1, and the data is safely written twice in directly Windows readable form. So, for a potential lower cost (avoid buying the RAID controller), recovery is easy and faster. It's almost like unRAID, you can take the drive to any machine and read it

 

 

I've noted MANY times that RAID is NOT a backup.    A RAID-1 mirror provides fault-tolerance, but problems can (and do) easily impact both elements of the RAID.

 

For an OS drive, you need to create frequent images of the OS (once/month is generally plenty -- although updating it after any significant change in installed programs is a good idea); and of course daily backups of all data.

 

Gary, The question is about covering about covering the interval between backups. Daily backups are already in place, far more frequent than your suggested monthly. Yes, backup are required.  SFT (System Fault Tolerance) III is specifically mentioned. This is about fault tolerance and high availability.

The non-free Crashplan version backups files every time it changes. There are many others file based backup utilities that do the same; PC Magazine elected Acronis Backup and Recovery as the best of them.

 

http://www.pcmag.com/article2/0,2817,2366426,00.asp

 

To real-time file backup, it should be enough.

Gary, The question is about covering about covering the interval between backups. Daily backups are already in place, far more frequent than your suggested monthly. Yes, backup are required.  SFT (System Fault Tolerance) III is specifically mentioned. This is about fault tolerance and high availability.

 

Actually I think the issue was that he lost a bunch of registered programs due to no backup of the OS except a RAID-1 mirror.  I did, however, miss bubba's next-to-last paragraph where he notes he now has the OS imaged nightly ... so that's clearly well covered now.    That, coupled with frequent data backups is much better than the previous setup;  and if the file backups are switched to a real-time backup utility this will be a very well protected setup.

 

The non-free Crashplan version backups files every time it changes. There are many others file based backup utilities that do the same; PC Magazine elected Acronis Backup and Recovery as the best of them.

 

http://www.pcmag.com/article2/0,2817,2366426,00.asp

 

To real-time file backup, it should be enough.

 

As the review states, Acronis is extremely complex to install and setup. It is not care-free once installed.

 

Crashplan has difficulties with open files, and is a hog of CPU, disk and network bandwidth. I use it for version backups, it crawls the filesystem. On a 400GB SSD filesystem it can miss a 15 minute cycle.

 

A filesystem write splitter is the gem used by Avere, EMC, etc. Not cheap and again corruption is instantly replicated

I wont be so fast to say the controller did the corruption.

 

Oh I will.  This was a Dell PERC HW RAID, not fake-RAID.  Looking at the partition table (and indeed the entire first several sectors) there was bogus data written, and it was DIFFERENT data on the two disks in the mirror.  Since the OS can't even see the two individual drives behind the HW RAID, that corruption was most likely caused by the controller.  And not likely a failure of the disk circuits itself, unless BOTH disks at the same time.

 

 

 

 

Yup, sounds like it was the controller. My luck is not so good. Typically when the controller starts writing badly, it writes all over the drive, not just the start.

Are there any current products that provide disk mirroring between 2 different servers with failover?  I don't mean WSFC where you have multiple servers that all reach into shared storage, but two different servers each with one disk in a RAID-1 mirror.

 

Another potential solution would be some type of realtime backup, where file changes are backed up to a different server each time a file is closed/modified.

 

Unfortunately, because of his industry, there are several mandatory software packages he uses that are Windows only and HAVE to be installed on a Windows server.

 

 

Any suggestions?

 

What about something like GlusterFS?

I'd set up a SAN based on that and provide iSCSI targets or CIFS shares for Windoze to use or even install on.