Software RAID or folder synchronization?

[Tsuroerusu]

Yesterday I ordered two 500 GB drives (One for backup), hopefully I will get them soon. Since there is no option, for me, to use Sun's ZFS file system (Solaris/OpenSolaris does not run, on pretty much anything, without proprietary drivers and components [1], and FreeBSD 7's ZFS port is not ready for production yet, nor is FreeBSD 7.x itself quite ready for production yet, according to what I have heard), I was planning to either write some shell scripts to set up as a cron job, or find some folder synchronization program that would copy any new or changed files to the other drives, and remove deleted ones on a regular basis. However, I was wondering, does anybody in here have any experience with software RAID-1 under GNU/Linux? How well does it work? How reliable is it? Can anybody recommend it?

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[1] http://www.opensolaris.org/os/about/no_source/

[diazamet]

If you are interested in ZFS, have you looked as Nexenta (http://www.nexenta.org/os)? It's an OS/Distribution that uses the OpenSolaris kernel with the GNU userland tools.

You would just need to check if the drivers you need are opensource or not.

[Tsuroerusu]

If you are interested in ZFS, have you looked as Nexenta (http://www.nexenta.org/os)? It's an OS/Distribution that uses the OpenSolaris kernel with the GNU userland tools.

You would just need to check if the drivers you need are opensource or not.

I have already been looking at that, and even the drivers for a freaking Realtek 10/100 ethernet networking card, and even more astonishingly a generic IDE HBA driver ... are proprietary!! I'm willing to bet that the Linux kernel and all of the BSDs have had this for close to 10 years.

Sadly no Solaris distribution is an option, and FreeBSD's ZFS support so far is just experimental. So ZFS is not an option, which is sad, because it's like THE solution I need. * sigh * , oh well that's life! Maybe things will change in the future, preferably sooner than later.

Thanks for the tip anyway, I appreciate it.

[snarkout]

I'd avoid softraid, personally.

[diazamet]

Why would you avoid softraid?

[snarkout]

It eats cpu, fails, and generally sucks. If it were worth a shit people worldwide would throw their expensive raid cards in the trash to go with fakeraid.

[Patrick]

I use one of these 3ware Raid cards in my server:
http://www.newegg.com/Product/Product.a ... 6816116030

I have 2x 500 gig hard drives with RAID1 mirroring. Been working like a champ for over a year.

[Tsuroerusu]

I use one of these 3ware Raid cards in my server:
http://www.newegg.com/Product/Product.a ... 6816116030

It's extremely weird, I can't find any 3ware controllers that costs less than 850 dollars in Denmark. I could buy one from another country within the EU, but that would be a pain if it ever broke and I had to return it. Buying one from the US is not a good option because of import taxes (Within the EU there's no sorts of import taxes).

I have 2x 500 gig hard drives with RAID1 mirroring. Been working like a champ for over a year.

The real test of a RAID controller though, is it's ability to recover from a problem, and the steps needed to restore the array to normal function when a problem has occurred. Have you had the chance to test that on your 3ware controller?

[Patrick]

The real test of a RAID controller though, is it's ability to recover from a problem, and the steps needed to restore the array to normal function when a problem has occurred. Have you had the chance to test that on your 3ware controller?

Not yet (knock on wood).

[jnash2001]

why not "rsync --delete" every night?
it can even archive the deleted files, iirc.
one package, one script, less fiddling

[HerbVista]

Several years ago I tried software RAID-1 on SuSE 8.x
I tested the mirror by disconnecting a drive ... at boot time the "MD" software kept complaining that "disk quorum" wasn't met ... and as a result the "md" software would not activate the raid group ...
... I couldn't figure how to "ignore quorum" to force the MD software to bring the raid-1 group online ...
... I may have missed an option to ignore quorum when building the Raid Group.

In any case, my point it to actually test the case where a drive fails before putting to much important data on the system.

I didn't see any performance issues with the software RAID-1 but I did not push a lot if I/O's ...

I usually use 3-Ware Raid cards for hardware Raid when using bare metal Linux.

Lately on small systems I generally just use motherboard/chipset provided Raid-1 groups and use XP Pro to get driver support and then use VMWare to provide Linux images on the raid protected drives ... not a servers solution.

Some of my suggestions are expensive however ... and modeled after commercial approaches ....