Messages posted by: Horn

Brahim wrote:

badough wrote:Very good news!
Users can certainly only use the Snapshot feature with mhddfs.

I have a quick question about this: does this mean if we write directly to the underlying DRU instead of the view that the realtime protection won't work? Not a deal breaker but it's something that should be made clear to the users.

Certainly! On my media server I have some small ancillary files that are prone to changing (nfo, tbn, thumbs.db, etc). Since this is a media server I really don't care about any files on this box under a certain size and since they tend to change I'd like to exclude all of them from the parity calculations. It's not a deal breaker for sure since I can exclude by extension but in my mind it would be another nice feature to have.

Would it be possible to get Flexraid to ignore files under a certain size?

How does Flexraid deal with symbolic links? If I have a /mnt/disk1 as one of my DRUs and there is a link /mnt/disk1/link that points to another disk. Will the data in link be included in the parity? If so, is there an easy way to prevent this?

I'm currently using mhddfs with flexraid and I have to say it works pretty well. MHDDFS doesn't hide your disks so flexraid can still work its magic on the underlying disks.

The way I have it setup is:
Data units:
/mnt/fs1/
/mnt/fs2/
/mnt/fs3/
/mnt/fs4/

Parity:
/mnt/parity/

MHDDFS:
/raidroot/ - this just points to the /mnt/fs* drives and makes it all look like one drive.

If this is something you need I wouldn't wait for flexraid-live to be on linux. This setup works perfectly for me.

Glad I could help. I've been using plain old software raid in linux for the past few years but upgrading it has always been a pain so once my new drives get here it's time to move onto flexraid and hopefully save myself a few headaches.

Sorry to bump such an old thread but I can't get the web interface to start automatically using this script. If I run it manually everything comes up fine but if I let the start up process run the script only the flexraid process starts. Any ideas?

By your silence I'm guessing this isn't something that flexraid can handle so on my lunch break I wrote up a quick and dirty python script to make sure all of the drives are mount and in the right place

:

import re
import subprocess
import sys

def main():
        f = open('/opt/flexraid/mountlist', 'r')
        savedinfo = {} #uuid : mount
        for line in f:
                data = line.partition(';')
                savedinfo[data[2]] = data[0]

realdrives = {} #device : uuid
        realmounts = {} #mount : device

output=subprocess.Popen("mount",stdout=subprocess.PIPE).communicate()[0]
        for line in output.split('\n'):
                data = re.search('(\S+) on (\S+)', line)
                if not data is None:
                        realmounts[data.group(2)] = data.group(1)

output=subprocess.Popen("blkid",stdout=subprocess.PIPE).communicate()[0]
        for line in output.split('\n'):
                data = re.search("(/dev/sd[a-z]\d).*UUID=\"([\w,-]+)\"", line)
                if not data is None:
                        realdrives[data.group(1)] = data.group(2)

error = False

#every drive listed has to be mounted
        for mount in savedinfo.itervalues():
                if not mount in realmounts:
                        error = True

#only check if the first passed
        if error == False:
                #every uuid in the saved file has to match mounted drives
                for uuid,mount in savedinfo.items():
                        if uuid.strip() != realdrives[realmounts[mount]].strip():
                                error = True
        if error:
                return -1
        return 0

if __name__ == "__main__":
        sys.exit(main())

This takes a file that contains a list of mount points and the UUID's of the device they're mounted to. Here's an example:

I added a check to the init.d script that someone else here supplied and now flexraid won't start unless all the drives it needs are in the right place. This was written on 9.04 ubuntu but it should work on most linux distros.

Well, I tried testing this out in VMWare and it doesn't seem to be detecting the missing drive.

my setup is:
/dev/sdb1 is mounted to /mnt/fs1
/dev/sdc1 is mounted to /mnt/fs2
/dev/sdd1 is mounted to /mnt/fs3

/mnt/fs1 & /mnt/fs2 are the DRU's and /mnt/fs3 is the PPU. I shutdown, removed the drive that was mounted to /mnt/fs2 (one of the DRU's) and booted up. I then opened up flexraid and hit sync. Flexraid then synched the data without error. Unless I'm mistaken this means that I've lost my parity information for the 'dead' drive.

Am I understanding this properly?

Brahim wrote:FlexRAID has a built-in logic to detect failed drives and will abort the rsynch whenever that happens.

Thanks for the fast reply! Sorry if my question sounds dumb but a lot about flexraid sounds too good to be true.

Flexraid seems like a nearly perfect product for my home media server but I do have one concern. If a drive fails and I have sync setup to run automatically won't I lose the data on the failed drive? Since Flexraid doesn't seem to access the drives directly how would I prevent sync from running if one of the drives disappear?

My server is running ubuntu 8.04 LTS. I don't mind having to do some scripting to ensure this doesn't happen so I'm just trying to figure out what must be done to keep my stuff as safe as possible.