Apr, 2014 so our target it to remove devsdc1 and add a new disk in place of that. If you have a spare, you can grow it by forcing the active drive count for the array to grow. Some common tasks, such as assembling all arrays, can be simplified by. Apr 14, 2015 add a 3rd drive to a existing raid1 not as spare from. Adding a drive to a raid 6 array with mdadm the linux ham. If replacing all the devices repeat the above for each device, allowing the array to resync between repetitions. It will then attempt to remove the spare from the second drive and add it to the first. In this part, well add a disk to an existing array to first as a hot spare, then to extend the size of the array. Contribute to neilbrownmdadm development by creating an account on github. Perhaps there is also an option to directly add a spare device, i cant find that one quickly in man mdadm. Spares cannot be added to nonredundant arrays raid 0 because the array will not survive the failure of a drive. I had a spare 300gb drive with which to replace it, so the removal and restructure of the raid devices would be easy.
It might take some time to complete syncing the drives. One thing that repeatedly crops up is people trying to rebuild an array, but they have no spare sata slots to add the new drive. Adding an extra disk to an mdadm array zack reed design. Just add more than one spare, and grow the array to the required number of devices. You may want to use the xgvfsshow option, will let you see your raid1 in the sidebar of your file manager. My thing however is that i am not familiar with hardware installation on a server of this type nor am i. Right now feb 20 im growing the array from 6 to 8 drives. When mdadm detects that an array in a spare group has fewer active devices than necessary for the complete array, and has no spare devices, it will look for another array in the same spare group that has a full complement of working drive and a spare. When you grow the array, you tell mdadm how many drives the new array should be and it will pull in as many hot spares as you tell it to with the raiddevices parameter. After the spare was added, the device showed up in the procmdstat output with the s string to indicate that its a hot spare. Using mdadm, a single command like mdadm create verbose devmd0 levellinear raiddevices2 devsdb6 devsdc5 should create the array. Simple mdadm raid 1 not activating spare super user. Adding a hot spare to an md device prefetch technologies.
Get an add in card that adds extra sata slots, or a usb disk cradle preferably usb3, but usb2 will do. Jul 11, 2012 finally, you can add more than 1 drive at the same time. You can use whole disks devsdb, devsdc or individual partitions devsdb1, devsdc1 as a. Basic tutorial of using mdadm command to operate raid in. How to replace faulty device from raid array tecadmin. For future travellers, when you add drives to an existing array, they will simply sit there as hot spares. Depending on the type of raid for example, with raid1, mdadm may add the device as a spare without syncing data to it. Jul 06, 2011 just a quicky reference on removing a drive for those of you using mdadm. This cheat sheet will show the most common usages of mdadm to manage software raid arrays. Add a 3rd drive to a existing raid1 not as spare from. Adding an extra disk to an mdadm array zack reed design and. The drives are small and fast 300gb 10k rpm velociraptors, so i would think it would have synced by now.
These commands instruct mdadm to add the old disk to the new arrays. Once the partitions have been created, you can add them to the corresponding raid devices using mdadm add commands. Aug 16, 2016 to add a spare, simply pass in the array and the new device to the mdadm add command. I have a raid 10 array that i created when i installed ubuntu server 10. How to configure a hot spare on raid5 applications. This makes the raid5 array using sda1, sdb1 and sdc1. If the array is not in a degraded state, the new device will be added as a spare. When i installed it, it gave me the option of installing a spare drive.
It will automatically use the spare as soon as the array becomes degraded, which either happened before you added the spare, or when you failed and removed the bad drive. To view the status of an array, from a terminal prompt enter. Nov 19, 2011 if you remember from part one, we setup a 3 disk mdadm raid5 array, created a filesystem on it, and set it up to automatically mount. Im promising myself that this is the final size for this array. Once added, the linux kernel immediately starts resyncing contents of the arrays onto the new drive. We own a poweredge t110 server with 3 250gb sata hard drives in a raid5 array on a sparc controller. This guide shows how to remove a failed hard drive from a linux raid1 array software raid, and how to add a new hard disk to the raid1 array without losing data. Managing software raid red hat enterprise linux 5 red. The array had 3 sata disks and 1 ide, and as i was planning to replace the ide disk with an sata one i just moved the 3 sata disks and added the new disk later. Conf5 name top nf configuration for management of software raid with mdadm synopsis top etcnf description top mdadm is a tool for creating, managing, and monitoring raid devices using the md driver in linux. It is used in modern gnulinux distributions in place of older software raid utilities such as raidtools2 or raidtools.
It does not currently support automatic inclusion of a new drive as a spare in some array. After rebuild is complete it will no longer show as spare. Its is a tool for creating, managing, and monitoring raid devices using the md driver. A hot spare, as in normal raid terminology, does not have anything to do with the extra drives present in a raid 5 or raid 6 array it is an extra drive meant to take over as soon as a drive in the array has failed. Using mdadm details will list a drive as spare while its rebuilding. Replacing a failed hard drive in a software raid1 array. Setting up raid using mdadm on existing drive guy rutenberg. You can see a raid 5 with 6 disks and it states spare1. Check the status with sudo mdadm d devmd127 and it should show that either it is in the process of rebuilding, or it has finished and everything is fine.
If an array is using a writeintent bitmap, then devices which have been removed can be readded in a way that avoids a full reconstruction but instead just updated the blocks that have changed since the. When adding new drives to an existing mdadm array, do i. How to set up software raid 1 on an existing linux distribution. The mdadm utility can be used to view the status of an array, add disks to an array, remove disks, etc.
Use mdadm to hot add the new drive partition to the raid array configure mdadm. Note that mdadm will only add devices to an array which were previously working active or spare parts of that array. If you remember from part one, we setup a 3 disk mdadm raid5 array, created a filesystem on it, and set it up to automatically mount. To add a spare, simply pass in the array and the new device to the mdadm add command. Aug 16, 2016 to create a raid 0 array with these components, pass them in to the mdadm create command. If you want to add a fourth drive as spare, this must be done later. Replacing a failing raid 6 drive with mdadm enable sysadmin. Replace a failing drive in a raid6 array using mdadm. To start the actual growing of the array we then add the new drive to the.
Mar 26, 2020 to automatically mount the raid 1 logical drive on boot time, add an entry in etcfstab file like below. Learn how to replace a failing soft raid 6 drive with the mdadm utility. I have also tried using mdadm zerosuperblock devsdm before adding, with the same result. To add the hot spare, i ran the mdadm utility with the add option, the md device to add the spare to, and the spare device to use. Verify recovery now that the drive has successfully been added to the array, we can verify the rebuilding process is in progress.
In this part, well add a disk to an existing array to first as a hot spare. There is a new version of this tutorial available that uses gdisk instead of sfdisk to support gpt partitions. Mar 08, 2009 mdadm is the modern tool most linux distributions use these days to manage software raid arrays. Growing a raid5 array with mdadm is a fairly simple though slow task. You can increase the number of disks the raid uses by using grow with the raiddevices option.203 695 636 1044 320 157 645 1376 194 228 567 1339 643 1052 205 473 267 628 643 472 223 555 1169 911 461 1068 1455 405 470 1192 1056 673 1219 1180 1229 438 600 1215 1290 1077 1351 1226 1408 1290 536 1090 200 578 730 243