I agree about the complexity of the RAID situation. But it can be narrowed down a bit.
Since the claim is made there were only two hard drives, the only possibilities are: RAID 0 - "striping". In which case his data will probably not be recoverable, and he would be unable to boot. RAID 1 - "mirroring". In which case the data may be recoverable. This is probably the case, since from the description the machine is booting but the login process is unsuccessful. If the RAID is set up with hardware, there may be entry into the controller from the BIOS boot process. If the RAID is set up in Linux software, then you need to get logged in somehow with root privileges. Details may vary a bit depending on which Linux distribution is involved (which was not mentioned). You could try to boot into "rescue mode" from the Linux installation media (DVD or USB stick, usually). Or you could try to boot into "single user mode" by altering the boot command during the boot procedure (details will vary with distribution). Or you could try setting to boot up in nongraphical mode. Like I say, this varies with Linux distribution so I won't try to give a line by line set of instructions. My experience is all with Fedor and Scientific Linux. Once you are in, you need to assess the situation. If RAID is set up with software, there will be a configuration file, typically /etc/mdadm.conf, and a status file, typically /proc/mdstat. You can look for these files for clues to how the RAID is set up, and what its status is. You would need to figure out how your existing drive is configured by checking out the partition arrangement with /usr/sbin/fdisk or /usr/sbin/parted. Then you would need to set up partitions on the brand new drive in the same way. Once the partitions exist, you would try to add the partitions into the RAID volume with /usr/sbin/mdadm. You are going to need to read the man pages for mdadm and probably search for help online. Once the RAID set is successfully reconfigured, it would take probably a few hours to copy the data from the good device to the new one. BTW, if anyone is using HPE SSDs they need to be aware of this: https://www.zdnet.com/article/hpe-tells-users-to-patch-ssds-to-prevent-failure-after-32768-hours-of-operation/ HPE tells users to patch SSDs to prevent failure after 32,768 hours of operation On 2019-11-27 09:03, Kay Diederichs wrote: Hi Vaheh, RAID on Linux comes in different flavours and levels; the flavours are software RAID (mdadm) and hardware RAID (dedicated RAID controller or motherboard), and the levels are RAID0 RAID1 RAID5 RAID6 RAID10 and a few others. These details influence what the user will notice when a disk goes bad. Without knowing what you have, it is difficult to help. As an example, by default in my lab we have the operating system on mdadm RAID1 which consists of two disks that mirror each other. If one of the disks fails, typically we only notice this when inspecting the system log files. Replacing the disk, and re-silvering the RAID1 is not trivial and requires some reading of material on the web. It sounds like you don't have this type of RAID1, or maybe there is some mis-configuration. good luck, Kay On Tue, 26 Nov 2019 21:05:54 +0000, Oganesyan, Vaheh <vaheh.oganes...@astrazeneca.com><mailto:vaheh.oganes...@astrazeneca.com> wrote: Hello ccp4-ers, A bit off topic (actually a lot off topic) question regarding RAID array system. On linux box one of two hard drives failed. I've found identical one and replaced it. Can someone point me in the direction where I can get instructions on what to do next to be able to login? Currently computer starts with no error messages, comes to the login window, takes username and password from me and then flashes and comes back to login window. Thank you for your help. Regards, Vaheh Oganesyan, Ph.D. Scientist, Biologic Therapeutics ____________________________________________________________________ AstraZeneca R&D | Antibody Discovery and Protein Engineering One Medimmune Way, Gaithersburg, MD 20878 T: 301-398-5851 vaheh.oganes...@astrazeneca.com<mailto:vaheh.oganes...@astrazeneca.com><mailto:oganesy...@medimmune.com><mailto:oganesy...@medimmune.com> ________________________________ To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1 ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1 ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1 -- ======================================================================= All Things Serve the Beam ======================================================================= David J. 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