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Why is RAID 0 bad?
As others have said it roughly doubles the risk of failure of the data on it compared to a single disk. If you had 3 disks in raid 0, then 3x the risk, etc… This because you lose almost all data if any one disk fails.
Can you RAID 0 without losing data?
RAID 0 allows no redundancy, which means if a drive crash; all data will be lost forever. So, RAID 0 can be used as a performance booster, not as data backup.
Is RAID 0 a bad idea?
RAID 0 – Good if data is unimportant and can be lost, but performance is critical (such as with cache). RAID 1 – Good if you are looking to inexpensively gain additional data redundancy and/or read speeds. (This is a good base level for those looking to achieve high uptime and increase the performance of backups.)
Should I RAID 0 my HDD?
RAID0 is generally a bad idea. All data is split across all drives in the array. When it goes to read or write data it theoretically would double performance because 2 drives are each writing/reading half the data. It also doubles your chance of failure because you have 2 drives and if EITHER fails ALL data is lost.
Why does mdadm not mount the RAID array?
A few days ago there was a power failure and UPS failure. It was not the first time unfortunately. The OS is on a separate SSD disk ( /dev/sda) which is not part of the raid array, so it boots but it cannot mount the array anymore. Sometimes /dev/md0 does not exists at all.
Is there a way to recover raid from mdadm?
Feed the resulting array to mdadm and pray to your deity of choice that md will be able to make sense of the resulting situation. If you are lucky, it will be able to, and will restore most of the data to readable condition now that there are no read errors (since you brought in new disks). Again, there may be some corruption in places.
Is the / dev / sda part of the RAID array?
Even if the first backup is corrupted, ext4 will have created others. You have several problems. First, you say that /dev/sda is your system disk, not part of a RAID array, with the OS on it. Well, look in the exact syslog snippet you showed us:
How to recover raid from two bad disks?
If you have two bad disks you need to choose less bad disk and it must be recovered to new disk by program ddrecovery. Remove this bad disk and insert the new recovered disk to the same place. Then you will can restore RAID 5 array with one missed disk (by example sdc) by command: Be sure that chunk parameter is the same as on good disks.