Here i go again, Linux what flavour? - Page 2

LeperousDust · 28-10-2007, 20:38

Currently zero building a hardware RAID5 array with the RocketRAID card, and i'll leave it going until its done unless i'm thourghly convince otherwise... This is usually how my linux installs go, just generally too much hassle with very little outcome, or any outcome thats worth the input

Mark · 28-10-2007, 20:44

IIRC the onboard intel RAID is another "fakeraid" solution that has the same problem the RocketRAID cards do. Not surprised that broke.

Dr. Z · 28-10-2007, 20:46

Neither the rocketraid card nor your motherboard are actually raid cards. UNDER ABSOLUTELY NO CIRCUMSTANCES try and convince the fakeraid BIOS to build you an array. Not only will it not do a jot, you increase the risk of it thinking your array is broken and trying to repair it, nuking everything on both drives.

If you need more convinicing, I could put that in bold for you and make it bigger

I am trying to find a guide I wrote on how to use mdadm to build you a proper software RAID array.

LeperousDust · 28-10-2007, 20:47

Lol, greeeat, and the Promise Fasktrack controller i assume is the same? So i have three what seem hardware raid solutions in this one PC, none of which actually play nice within linux, and i wonder why it isn't mainstream... Anyway, forget that then, how do i (**easily**) set up my OS mirrored?

//Edit: Loud and clear DRZ, so how DO i raid the OS then?

Dr. Z · 28-10-2007, 21:05

They only seem like hardware raid because the windows drivers lie to you and hide the drives so that you only see whatever logical disks you set up. They aren't actual RAID controllers as such. Its not so much a case of them not playing nice under Linux, its a case of Linux showing them up for what they are!

If you want to RAID the OS, its a bit more tricky but IMO there is no need to do so. A single drive should provide you with enough speed to run the sort of thing you want to run and then from there you can build an array to house your data.

Obviously you aren't going to have any OS redundancy but its a swift job to back up your OS disk (Acronis or similar will do this for you with no drama) and so you are covered. In any case, as I found out as I "took charge" of the engineering side of things at Shock, RAID is an availability solution, not a backup one!

Simply install Ubuntu on a single drive with no fakeraid trickery and you should be sweet

EDIT:

http://www.linuxhomenetworking.com/w..._Software_RAID

Have a read of that, it will take you through what you need to do

LeperousDust · 28-10-2007, 22:20

Fair enough, i'll disable it all in a bit, and install to one of the samsung drives, is there a process from which i can automate a full backup 1:1 mirror image (rather than compressed image) of the full OS install onto the other samsung? So i literally can just swap the boot point over if for some reason my drive dies? I want failure recovery easy, i dont want to be arsing around trying to get my data back from within linux you see thats all

Dr. Z · 28-10-2007, 22:27

Acronis has a tool that will create one-click recovery thingamybobbers. Best run from a seperate machine though - would you want both drives going up in smoke if the PSU died or something and decided to take out a drive or two?

IF you keep your data nice and tidily just on the md raid volume, it can be imported back into any linux fairly easily I think - the FS type is set as "Linux Raid" so it should all just figure itself out if it came to it. Not sure if the Ubuntu LiveCDs have mdraid support as it stands (I remember having to get it through apt) but thats yet another avenue for disaster recovery!

Im sure Daz will have a better take on the backup side of things as its something I am fairly green at

LeperousDust · 28-10-2007, 22:56

I've kinda thought of that too, both OS hard drives would be on two different rails which would mean the PSU would have to go seriously postal to do something that drastic, at that point i wouldnt be recovering the other 4 * 400gb drives anyways by the sound of it, which was the whole point

I've got three hard drives so i could get really anal (if Daz gets in here

) and do incremental backups to the tune of two (or three not sure how you count it) drives! I'll look into acronis, but something more automated i could run once a week/day whatever that ran within Ubuntu would be great for me...

Dr. Z · 28-10-2007, 23:48

Acronis can be scheduled to do incremental backups

4*400Gb in RAID5 should give you a tasty amount of storage with some redundancy, and is fine in mdraid.

Backing up 1.2Tb could be interesting though!

My mdraid array:

Code:

/dev/md0:
        Version : 00.90.03
  Creation Time : Mon Sep  4 01:09:20 2006
     Raid Level : raid1
     Array Size : 312568576 (298.09 GiB 320.07 GB)
    Device Size : 312568576 (298.09 GiB 320.07 GB)
   Raid Devices : 2
  Total Devices : 2
Preferred Minor : 0
    Persistence : Superblock is persistent

    Update Time : Fri Mar 30 07:25:05 2007
          State : clean
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0

           UUID : 1afceb08:d3baa4b2:41c3fe51:be373b4d
         Events : 0.354828

    Number   Major   Minor   RaidDevice State
       0       8        1        0      active sync   /dev/sda1
       1       8       17        1      active sync   /dev/sdb1

Mark · 29-10-2007, 00:03

How often do you need to back up the OS?

If not often, then an external USB caddy will do the trick.

You can take a replica of an entire disk in Linux - it's dead easy in fact (far easier than Windows), but it's best to be in single user mode with the whole lot mounted read-only if you want to do it that way (it'll usually work, but filesystem drivers tend not to like two things using the same bit of disk at once). Arconis sounds like a simpler solution to me.

DRZ - you seem to have got the RAID mantra down. Daz ought to copyright that. I ought to take heed as well really, but I have so much damn stuff and no idea where to put it all. :/

28-10-2007, 20:38	#11
LeperousDust Bananaman Join Date: Jul 2006 Location: Liverpool/Edinburgh Posts: 4,817	Currently zero building a hardware RAID5 array with the RocketRAID card, and i'll leave it going until its done unless i'm thourghly convince otherwise... This is usually how my linux installs go, just generally too much hassle with very little outcome, or any outcome thats worth the input __________________

28-10-2007, 20:46	#13
Dr. Z I'm going for a scuttle... Join Date: Jul 2006 Posts: 2,021	Neither the rocketraid card nor your motherboard are actually raid cards. UNDER ABSOLUTELY NO CIRCUMSTANCES try and convince the fakeraid BIOS to build you an array. Not only will it not do a jot, you increase the risk of it thinking your array is broken and trying to repair it, nuking everything on both drives. If you need more convinicing, I could put that in bold for you and make it bigger I am trying to find a guide I wrote on how to use mdadm to build you a proper software RAID array. __________________

28-10-2007, 20:47	#14
LeperousDust Bananaman Join Date: Jul 2006 Location: Liverpool/Edinburgh Posts: 4,817	Lol, greeeat, and the Promise Fasktrack controller i assume is the same? So i have three what seem hardware raid solutions in this one PC, none of which actually play nice within linux, and i wonder why it isn't mainstream... Anyway, forget that then, how do i (easily) set up my OS mirrored? //Edit: Loud and clear DRZ, so how DO i raid the OS then? __________________ Last edited by LeperousDust; 28-10-2007 at 20:50.

28-10-2007, 21:05	#15
Dr. Z I'm going for a scuttle... Join Date: Jul 2006 Posts: 2,021	They only seem like hardware raid because the windows drivers lie to you and hide the drives so that you only see whatever logical disks you set up. They aren't actual RAID controllers as such. Its not so much a case of them not playing nice under Linux, its a case of Linux showing them up for what they are! If you want to RAID the OS, its a bit more tricky but IMO there is no need to do so. A single drive should provide you with enough speed to run the sort of thing you want to run and then from there you can build an array to house your data. Obviously you aren't going to have any OS redundancy but its a swift job to back up your OS disk (Acronis or similar will do this for you with no drama) and so you are covered. In any case, as I found out as I "took charge" of the engineering side of things at Shock, RAID is an availability solution, not a backup one! Simply install Ubuntu on a single drive with no fakeraid trickery and you should be sweet EDIT: http://www.linuxhomenetworking.com/w..._Software_RAID Have a read of that, it will take you through what you need to do __________________ Last edited by Dr. Z; 28-10-2007 at 21:12.

28-10-2007, 22:20	#16
LeperousDust Bananaman Join Date: Jul 2006 Location: Liverpool/Edinburgh Posts: 4,817	Fair enough, i'll disable it all in a bit, and install to one of the samsung drives, is there a process from which i can automate a full backup 1:1 mirror image (rather than compressed image) of the full OS install onto the other samsung? So i literally can just swap the boot point over if for some reason my drive dies? I want failure recovery easy, i dont want to be arsing around trying to get my data back from within linux you see thats all __________________

28-10-2007, 20:44	#12
Mark Screaming Orgasm Join Date: Jul 2006 Location: Newbury Posts: 15,194	IIRC the onboard intel RAID is another "fakeraid" solution that has the same problem the RocketRAID cards do. Not surprised that broke.

28-10-2007, 22:27	#17
Dr. Z I'm going for a scuttle... Join Date: Jul 2006 Posts: 2,021	Acronis has a tool that will create one-click recovery thingamybobbers. Best run from a seperate machine though - would you want both drives going up in smoke if the PSU died or something and decided to take out a drive or two? IF you keep your data nice and tidily just on the md raid volume, it can be imported back into any linux fairly easily I think - the FS type is set as "Linux Raid" so it should all just figure itself out if it came to it. Not sure if the Ubuntu LiveCDs have mdraid support as it stands (I remember having to get it through apt) but thats yet another avenue for disaster recovery! Im sure Daz will have a better take on the backup side of things as its something I am fairly green at __________________

28-10-2007, 22:56	#18
LeperousDust Bananaman Join Date: Jul 2006 Location: Liverpool/Edinburgh Posts: 4,817	I've kinda thought of that too, both OS hard drives would be on two different rails which would mean the PSU would have to go seriously postal to do something that drastic, at that point i wouldnt be recovering the other 4 * 400gb drives anyways by the sound of it, which was the whole point I've got three hard drives so i could get really anal (if Daz gets in here ) and do incremental backups to the tune of two (or three not sure how you count it) drives! I'll look into acronis, but something more automated i could run once a week/day whatever that ran within Ubuntu would be great for me... __________________

29-10-2007, 00:03	#20
Mark Screaming Orgasm Join Date: Jul 2006 Location: Newbury Posts: 15,194	How often do you need to back up the OS? If not often, then an external USB caddy will do the trick. You can take a replica of an entire disk in Linux - it's dead easy in fact (far easier than Windows), but it's best to be in single user mode with the whole lot mounted read-only if you want to do it that way (it'll usually work, but filesystem drivers tend not to like two things using the same bit of disk at once). Arconis sounds like a simpler solution to me. DRZ - you seem to have got the RAID mantra down. Daz ought to copyright that. I ought to take heed as well really, but I have so much damn stuff and no idea where to put it all. :/ Last edited by Mark; 29-10-2007 at 00:06.