On 01/27/2013 10:13 PM, Sam Martin wrote: > Thanks Frank, > > But this is kind of my backup. I don't have any capacity to backup to > another drive/ext HDD.
Raid is not a backup. All data can easily get lost by one wrong command, e.g. someone does rm -rf /mountpoint (accidentally, some do because of wrongly-predicted shell-expansion) and suddenly all data are gone... You would be probably better off not having a raid but one main HDD for your data and one for your backup. > The OS is running off a small SSD. > I have 2x3TB drives for data running in RAID1. > > I assumed with software raid, the drives couldn't be used without being part > of the RAID config, i.e. presented via mdadm. > > I'm fairly new to Linux and software raid, so please forgive any stupid > /obvious comments. > > Am I right in thinking, I could get new OS up and running. Mount one of the > disks as a standard drives (not raid) and them somehow rebuild a raid based > with the data present? This might work, as someone already posted, depending on the metadata format. But I would never try this without being entirely sure, because -- as I have already mentioned -- a single wrong command (and that can also be a wrong mount) can damage your RAID. Why not try to restore the whole raid in one step. Although it seems more complex, I believe it is safer, because you do not rely on a specific metadata format. On the other hand you could also try to mount a device and if it fails, rebuild the raid using the one left as if the second HDD was just damaged but I would not recommend this. > What problems might I face using the raid config as is under 64bit dist? I guess there are none, unless you try to mount the devices without a raid array. > Thanks for your advice > > Sam > > > On Sunday, January 27, 2013 3:50:01 PM UTC, Frank wrote: >> On 01/27/2013 02:18 PM, Sam Martin wrote: >> >> >> >>> I'm about to reinstall linux using 64bit wheezy dist rather than the 32bit >>> on i inadvertently used. >> >>> >> >>> I've got a copy of /etc but I'm concerned that in /etc/mdadm/mdadm.config >>> there is no reference to the array. >> >>> >> >>> The only lines that are uncommented are >> >>> >> >>> CREATE owner=root group=disk mode=0660 auto=yes >> >>> HOMEHOST = <system> >> >>> MAILADDR root >> >> >> >> Why keeping a mdadm raid which incompatible binarys? Backup you data, >> >> install from scratch and restore your data, makes more sense to me. >> >> >> >>> Presuably is automatically detecting /dev/md0 (the raid vol)? >> >>> >> >>> Can anyone offer any opinion/advice on this? i don't want to be in a >>> position where i cannot get it back up. >> >> >> >> Make sure you have a working and up2date backup, a print out of your >> >> /etc/fstab and the contents from "cat /prod/mdstat" can be helpful as >> >> well if something goes wrong. >> >> >> >>> The raid is a simple mirror at the moment, but I'm guessing I cannot use it >>> without mdadm if it did go wrong? >> >> >> >> Of course, you can boot from both disks. Just change the device name in >> >> your bootloader from /dev/mdX to i.e the first detected SCSI / SATA disk >> >> /dev/sdaX. So if you screw up one of them, boot from the other device >> >> and resync your data. >> >> >> >> Best >> >> Frank >> >> >> >> >> >> -- >> >> To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org >> >> with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org >> >> Archive: http://lists.debian.org/51054a4e.8010...@dead-link.org -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/5106d261.5080...@web.de
