How To Create RAID Arrays with mdadm on Ubuntu 16.04 August 16, 2016 Linux's mdadm utility can be used to turn a group of underlying storage devices into different types of RAID arrays. So, let's say your server had 6 healthy hard drives. A drive fails (will not mount/detect, drops out of raid with errors) or is failing (SMART getting worse, etc). You need to swap out the bad drive. When you open the case you see. Six identical hard drives. How can you tell which one is no longer healthy/mounting/functioning? ![]() System would be linux, most likely ubuntu server, using at most simple software RAID. The hard drives would be SATA and connected directly to the motherboard. (no raid controller) I don't want to randomly disconnect drives until I pick the correct one. The drives all appear identical to me; I imagine there is some common way to identify which drive is which that I am unaware of. Does anyone have any pointers/tips/best practices? EDIT: I had wanted this to be 'generalized' in a hand-wavy sort of way, but it just came off as 'incomplete' and 'horrible'. Putting stickers on drives (depending on the design of the tray) may not be feasible. By the time the drive dies, the stickers could be dried up and fallen off. Technitium MAC Address Changer. One of the top contenders in the list of the MAC address changer tools is Technitium MAC Address Changer that lets you spoof or change the MAC address of your network adapter in no time. The user interface is simple and easy to use while it displays the status, speed, network connections, MAC address. Mac address changer for android. To temporarily change android MAC address without rooting the first thing you need is to know the MAC address. To find it on your tablet just touch the Menu key and go to Settings. Scroll down to About Tablet and there select Status. So Friend, In This Article you will see Some of the Best Mac Address changer apps for android device OS. You can easily change mac address in Your Android Smartphone with the help of these apps. You can easily change mac address in Your Android Smartphone with the help of these apps. How To Change MAC Address. Starting MAC address changer will list all available network adapters. Select the adapter you want to change the MAC address. You will get the details of your selection below. In the Information tab, find the Change MAC Address frame. Enter new MAC address in the field and click Change Now! 1- Simple way change: this will change your mac simply, wont reflect in wifi settings, you may not connect to secured password protected networks. This function mostly works with most users. 2- Hard way change: Now you will see the fake mac address in wifi settings, you can connect to secured password protected networks.
To undo this command, enter sudo nvram -d enable-legacy-orom-behavior. Mixed in key for mac. Whatever information is available to you can be used. The drives are referenced multiple ways under the /dev/ and /dev/disk/ path. To turn the light back off, just execute it again, changing locate to locate_off like so: ledctl locate_off=/dev/sda. Usually you would have to hope that the connections are labeled in some fashion then work from the identity of the failed device. For example.and someone would have to comment to correct me.if you have two IDE channels, you have up to 2 drives on each, you could have sda, sdb, sdc, and sdd. If sdd failed it would be the second drive on the cable of the second IDE channel. If it's SATA and like the system I have in the back room the ports are labeled for each of the sata drives. Again, drive lettering goes from a through whatever the drives go up to, starting at port 0 of the SATA connectors and moving up. If there are any manufacturing differences, the dmesg|grep sd or dmesg|grep hd should yield some clues. If you have the serial numbers available I think the hdparm command might give it to you in software so you can trace it that way. You might want to label the drives somewhere if that's the case so you don't have to worry about that when you find there's an issue.I knew there was another reason I preferred hardware RAID over software RAID.blinky lights. ![]() Really like the blinky lights. EDIT: smartctl, not hdparm, gives the serial number. Six internal HDDS? If they are external, hot swap drives, the hot swap carrier likely has an error light to help you identify the bad drive. Also many Raid management programs have an option to flash the light on a particular drive to determine which is which. If they are all internal with no lights, then you are down to your RAID software telling you which IDs are good, and looking at the SCSI IDs, etc to to figure it out. If they are set to auto, then your RAID controller doc should tell you what order in the SCSI chain the IDs are assigned. Take a backup now while things are still running! If you have no locate light and can't easily find the serial numbers on the outside of the drives, sometimes this cheesy technique can help: create a LOT of activity on that specific drive and then look for the drive with the activity LED on solid. It's best to follow up with a more detailed check of the serial number, but this can help narrow the search. E.g.: # while true; do dd if=/dev/disk/by-id/scsi-drive-that-is-dying of=/dev/null; sleep 1; done (The while loop is not technically needed, but it will keep things moving while you head to the data center. The 'sleep 1' helps avoid the high CPU usage created by a fast loop if the 'dd' fails due to say.
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