Well thought-out question! I’d go with Method 2, but that’s more of a personal preference. To me, the Method 2 Cons aren’t much of an issue. I don’t see the host OS outgrowing its 5-10GB partition, unless you start installing extra stuff on it, which you really shouldn’t. For the sake of simplicity and security, … Read more
RAID-5 is a fault-tolerance solution, not a data-integrity solution. Remember that RAID stands for Redundant Array of Inexpensive Disks. Disks are the atomic unit of redundancy — RAID doesn’t really care about data. You buy solutions that employ filesystems like WAFL or ZFS to address data redundancy and integrity. The RAID controller (hardware or software) … Read more
As said before, if more than two disks in a RAID-6 array die, the array is unrecoverable. However, three simultaneous disk failures are quite an unlikely event: it might very well be a case of a faulty enclosure, backplane and/or controller. You should try removing and re-inserting the disks, replacing the controller and/or the enclosure, … Read more
I think you’ve got it right. Make sure you understand and heed the warnings regarding growing RAID 5 in man 8 mdadm. Personally if I were growing an LVM volume, I would not be growing an existing RAID array to do it. I’d create another RAID array, create a new physvol from it, and add … Read more
It looks like the system splits up each drive into as many partitions as needed to create a series of RAID5 and/or RAID1 arrays that minimize the amount of unused space on the drives. Those RAID arrays then become physical volumes under LVM, which, in turn, presents all that storage as a single logical volume. … Read more
The terminology you are looking for is a “RAID level migration”. According to this, it’s possible. I haven’t done it, but the procedure looks like you should add the new drive as a hotspare to the existing array, then use mdadm to update the raid level and the number of raid devices.. You’ll need a … Read more
Just an addition to the solution that I found after I experienced the same issue. I followed dSebastien’s blog post on how to re-create the array: I found that that method of recreating the array worked better than this above method. However after re-creating the array, the volume was still not showing on the web … Read more
You’re not done with performance tuning yet. <driver name=”qemu” type=”raw” cache=”writethrough” io=’native’/> First is which I/O mechanism to use. QEMU has two asynchronous I/O mechanisms: POSIX AIO emulation using a pool of worker threads and native Linux AIO. Set either io=’native’ or io=’threads’ in your XML to benchmark each of these. Second is which caching … Read more
Likely your best bet is a hardware problem somewhere between your disks and up to and including your sas raid controller. I recommend trying: Run any diagnostic tools from the vendor/s if they are available Check/re-seat/replace cables strip out hardware components and swap out hardware in the chain that connects the disks to your raid … Read more
Your SMART Current Pending Sector has value 1. This means that there is a bad sector on the disk and the drive firmware is unable to reallocate it, but you still have zero reallocated sectors count so it probably recoverable even though your drive have been running for 5 years in not very healthy environment … Read more