DSM-G600, DNS-3xx and NSA-220 Hack Forum

Unfortunately no one can be told what fun_plug is - you have to see it for yourself.

You are not logged in.

Announcement

#1 2008-05-08 23:37:18

gnugu
Member
Registered: 2008-05-08
Posts: 27

RAID 1 as a backup.

Hello,

I have read here that RAID 1 is not for backing up your data.

I have this crazy idea and I would like to ask if it would work:
I have 3 hard drives A, B and C. I insert A and B into DNS323 and set them as RAID 1. Then once a week I pull B out and replace it with C. Next week I pull C out and put B back into the unit.

Will DNS automatically mirror A drive to B/C when inserted once a week? Would this work at all?

To make the things even more complicated two of the three hard drives are 250G and one is 160G.

Offline

 

#2 2008-05-09 00:14:37

fordem
Member
Registered: 2007-01-26
Posts: 1938

Re: RAID 1 as a backup.

Have you ever stopped to consider what the acronym means?

Originally it was Redundant Array of Inexpensive Disks and it has since been changed to Redundant Array of Independent Disks - either way - it's Redundant .... Disks.

What I will say is this - RAID - I don't care which level, was not designed to do what you're asking - I will leave it up to you to figure out if the DNS-323 will do what you want - suffice to say that if you have to ask, you're already behind the eight ball - good luck with your crazy idea.

Offline

 

#3 2008-05-09 00:16:42

bq041
Member
From: USA
Registered: 2008-03-19
Posts: 709

Re: RAID 1 as a backup.

gnugu,
By the way. No, it doesn't work that way.


DNS-323     F/W: 1.04b84  H/W: A1  ffp: 0.5  Drives: 2X 400 GB Seagate SATA-300
DNS-323     F/W: 1.05b28  H/W: B1  ffp: 0.5  Drives: 2X 1 TB  WD SATA-300
DSM-G600   F/W: 1.02       H/W: B                Drive:  500 GB WD ATA

Offline

 

#4 2008-05-09 00:26:07

gnugu
Member
Registered: 2008-05-08
Posts: 27

Re: RAID 1 as a backup.

Thanks for your responses.

fordem, I'm asking before I purchased DNS323 and the two 250G hard drives. So you letting me know that it's not going to work saves me some money. Thanks.

I'll research other topics that talk about USB backup.

Offline

 

#5 2008-05-09 12:51:59

index monkey
Member
From: UK
Registered: 2007-06-14
Posts: 112

Re: RAID 1 as a backup.

are you baiting fordem deliberately with a topic title like this? smile

Last edited by index monkey (2008-05-09 12:54:12)


DNS-323, HW B1, 2 x 2TB WD green, fw 1.08, fun_plug 0.5, transmission, automatic, nzbget newsreader & rsync time machine backup.

Offline

 

#6 2008-05-09 15:18:36

fordem
Member
Registered: 2007-01-26
Posts: 1938

Re: RAID 1 as a backup.

index monkey wrote:

are you baiting fordem deliberately with a topic title like this? smile

You know - when I saw the subject and read the post - the thought did cross my mind wink

Offline

 

#7 2008-05-09 16:50:40

NASuser
Member
Registered: 2008-05-01
Posts: 16

Re: RAID 1 as a backup.

RAID 1 is good for Back-up your Data.
But there isn't a solution, wich is 100% safe.

E.g. a fire can destroy the NAS with both drives in it.
But probably the risk isn't too high.

Offline

 

#8 2008-05-09 17:02:19

blahsome
Member
Registered: 2008-03-02
Posts: 157

Re: RAID 1 as a backup.

NASuser wrote:

RAID 1 is good for Back-up your Data.

Do you have a safe place to hide? You better do. smile

Offline

 

#9 2008-05-09 17:14:11

sjmac
Member
Registered: 2008-01-21
Posts: 222

Re: RAID 1 as a backup.

Hmm, or just refer to one of the other recent "never ending threads" to avoid another one?

:-)

http://dns323.kood.org/forum/t1869-Proo … ackup.html

Offline

 

#10 2008-05-09 17:19:10

sjmac
Member
Registered: 2008-01-21
Posts: 222

Re: RAID 1 as a backup.

gnugu

takoma asked a pretty similar question recently - in the middle of a thread, so tricky to find ...
http://dns323.kood.org/forum/p11820-200 … tml#p11820

Offline

 

#11 2008-05-09 18:27:18

gnugu
Member
Registered: 2008-05-08
Posts: 27

Re: RAID 1 as a backup.

NASuser,
that's exactly my point! That's why I want to rotate hard drives, so I have one in safety deposit box all the time.

fordem and index monkey,
yes I was hoping that fordem would reply. Now, how is rotating the hard drive once a week different from having a drive failure once a week? Isn't RAID1 supposed to save a day? Of course if something bad happens I wouldn't stick my backup hard drive from safety deposit box into the unit. I would try to get the data from USB enclosure.

Does it still sound crazy?

Anyway, I'm picking up my unit today and will test the scenario.

Thanks.

Offline

 

#12 2008-05-09 18:42:05

gnugu
Member
Registered: 2008-05-08
Posts: 27

Re: RAID 1 as a backup.

sjmac,
thanks a lot for those links!

Now I see what you mean. I guess I'm going to scrap my idea and have only one drive (for now) in DNS and back up to USB enclosure.

Can anybody suggest what is the best standard to use (which RAID) so I can easily insert new disk in the future without losing data?

Thanks.

Offline

 

#13 2008-05-09 18:52:11

sjmac
Member
Registered: 2008-01-21
Posts: 222

Re: RAID 1 as a backup.

"Standard" (separate disks) seems very trouble free in my experience, and I've never seen anyone on the forum complain that it isn't working as expected, and it will be the easiest to recover the data from if you ever need to move the hard disks in to another device, and the access speed seems the same as the RAID 0 (high speed) configuration.

Last edited by sjmac (2008-05-09 18:53:17)

Offline

 

#14 2008-05-09 18:52:55

fordem
Member
Registered: 2007-01-26
Posts: 1938

Re: RAID 1 as a backup.

NASuser wrote:

RAID 1 is good for Back-up your Data.
But there isn't a solution, wich is 100% safe.

E.g. a fire can destroy the NAS with both drives in it.
But probably the risk isn't too high.

Have you considered risks to the data - other than a fire?

May I suggest a few?

In no particular order (as they say when announcing the finalists in a beauty pagent)

Theft of the NAS
Damage to the NAS due to a power surge
Corruption of the data due to a power surge
Corruption of the data due to an improper shutdown
Corruption of the data due to an improper shutdown due to a power failure
Accidental deletion of one or more files
Deliberate deletion of one or more files
Corruption or deletion of files due to a virus

Offline

 

#15 2008-05-09 18:57:22

gnugu
Member
Registered: 2008-05-08
Posts: 27

Re: RAID 1 as a backup.

fordem wrote:

Have you considered risks to the data - other than a fire?

May I suggest a few?

In no particular order (as they say when announcing the finalists in a beauty pagent)

Theft of the NAS
Damage to the NAS due to a power surge
Corruption of the data due to a power surge
Corruption of the data due to an improper shutdown
Corruption of the data due to an improper shutdown due to a power failure
Accidental deletion of one or more files
Deliberate deletion of one or more files
Corruption or deletion of files due to a virus

I agree with all your points and that's why I want to have one drive out of my house at all times.

Offline

 

#16 2008-05-09 18:58:45

gnugu
Member
Registered: 2008-05-08
Posts: 27

Re: RAID 1 as a backup.

I like this forum! I'm learning a lot here!

Thank you all!

Offline

 

#17 2008-05-09 19:02:05

sjmac
Member
Registered: 2008-01-21
Posts: 222

Re: RAID 1 as a backup.

sjmac wrote:

"Standard" ... I've never seen anyone on the forum complain that it isn't working as expected...

Uh - maybe I have - does the DNS323 sometimes format the wrong drive by mistake if you add a second?

fordem says not: http://dns323.kood.org/forum/t1335-Form … -disk.html

But maybe you could make sure you only have the new disk in the device when you do your format, and put the original in after?

Offline

 

#18 2008-05-09 19:06:03

fordem
Member
Registered: 2007-01-26
Posts: 1938

Re: RAID 1 as a backup.

gnugu wrote:

yes I was hoping that fordem would reply. Now, how is rotating the hard drive once a week different from having a drive failure once a week? Isn't RAID1 supposed to save a day? Of course if something bad happens I wouldn't stick my backup hard drive from safety deposit box into the unit. I would try to get the data from USB enclosure.

Does it still sound crazy?

Anyway, I'm picking up my unit today and will test the scenario.

Thanks.

I chose not to respond in my usual fashion - you've already read the reasons why RAID1 is not a backup - so why repeat myself?

I'm not going to tell you that you can't do what you're trying to do - because you can - as you will find out when you try it - it will work, it can be done!!  What I am also not going to tell you is why you shouldn't do it - I will let you find out that for yourself, and sooner or later, in my opinion, sooner rather than later, you will have run into trouble and you will find out for yourself - why it's not a good idea - if you're unlucky, you'll lose a bunch of data and feel the pain for yourself - that way, you'll remember it.

I've been working with RAID for over fifteen years - I've learned some things along the way, like what works and what doesn't, and that hardware RAID works better (and is more expensive) than software RAID, and that software RAID - which is what this box has, is generally a pain in the behind when you start swapping disks around - if you want to read the posts and then go out and learn for yourself, I can't stop you.

So - again - good luck with your crazy idea.

Offline

 

#19 2008-05-09 19:13:22

gnugu
Member
Registered: 2008-05-08
Posts: 27

Re: RAID 1 as a backup.

fordem,
as I said in the post #12, I have read the links sjmac has posted and I am not going to learn it the hard way. I take your and others word for it. That's why I asked before I did something stupid. I stupid I would have done, since till yesterday I didn't even know what RAID was.

So thanks again for sharing your knowledge. I appreciate it and I WILL (that's the promise wink) learn from it.

Offline

 

#20 2008-05-09 19:13:25

fordem
Member
Registered: 2007-01-26
Posts: 1938

Re: RAID 1 as a backup.

sjmac wrote:

sjmac wrote:

"Standard" ... I've never seen anyone on the forum complain that it isn't working as expected...

Uh - maybe I have - does the DNS323 sometimes format the wrong drive by mistake if you add a second?

fordem says not: http://dns323.kood.org/forum/t1335-Form … -disk.html

But maybe you could make sure you only have the new disk in the device when you do your format, and put the original in after?

Actually - depending on the circumstances - it may format the wrong drive, I have managed to do this - about a week ago.

Also you can only remove one drive and format the other if you are running separate volumes - I would not suggest you try this if you're running RAID - I could tell you what would happen, but I don't want to prejudice Gnugu - besides - that information is already in the forum, and he's probably already read it wink

Like I said swapping drives with software RAID is generally a pain in the behind - and I'm going to guess that someone is going to become intimately familiar with mdadm before too long.

Offline

 

#21 2008-05-09 19:39:05

sjmac
Member
Registered: 2008-01-21
Posts: 222

Re: RAID 1 as a backup.

fordem wrote:

Actually - depending on the circumstances - it may format the wrong drive, I have managed to do this - about a week ago.

Ah - http://dns323.kood.org/forum/p14334-200 … tml#p14334

One of the nastier surprises in the device.

fordem wrote:

Like I said swapping drives with software RAID is generally a pain in the behind - and I'm going to guess that someone is going to become intimately familiar with mdadm before too long.

:-) I'm sure mdadm is a useful tool to know how to use - and maybe all the time I've spent learning how to rebuild partition tables will come in useful one day ...

Offline

 

#22 2008-05-15 20:11:51

gnugu
Member
Registered: 2008-05-08
Posts: 27

Re: RAID 1 as a backup.

First of all, thank you everyone for your responses.

Here is what I ended up doing:
- DNS-323 has one HDD formated as "Standard".
- Installed SVN on DNS-323 to have my "time machine".
- Have two Vantec Nexstar USB enclosures. One of them is sitting in the safety deposit box in the bank, one of them is at home. At the end of the day I manually run my xcopy script that copies all new changes from DNS-323 to USB enclosure. Once a week I rotate the two enclosures. I have no desire to automate the backup. Anything deleted on DNS-323 will still remain on USB enclosure because I use xcopy for backup.

Last edited by gnugu (2008-05-15 20:12:47)

Offline

 

#23 2008-05-16 00:44:19

sjmac
Member
Registered: 2008-01-21
Posts: 222

Re: RAID 1 as a backup.

Sounds pretty comprehensive to me - it must be very important data to be worth a trip to the bank each week!

Maybe one of the offsite backup services would be appropriate? Then files get encrypted and transfered over the net as they change, and you always have an offsite backup.

Offline

 

#24 2008-05-16 00:48:33

gnugu
Member
Registered: 2008-05-08
Posts: 27

Re: RAID 1 as a backup.

sjmac, that is an interesting suggestion. Never heard of such service. I'll look it up. Thanks.

Offline

 

#25 2008-05-16 05:47:04

blahsome
Member
Registered: 2008-03-02
Posts: 157

Re: RAID 1 as a backup.

I heard good things about mozy, but their home account apparently doesn't support network drives.

Offline

 

Board footer

Powered by PunBB
© Copyright 2002–2010 PunBB