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Before you go say that RAID 1 mirrors one drive and cannot mirror twice, that is not what I mean. Actually it can, though then it is often called RAID 1E. I have a WD Black 2 TB HDD and 2 WD Blue 1 TB HDD. The WD Black is to be the main drive, and I need data redundancy. Is it possible to use the two blues coupled together as RAID drives and the ...


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This entirely depends on your RAID controller, which you havent mentioned. From my experience RAID controllers are very forgiving when it comes to non matching drives. However, there are some that will complain, or wont even work drive if a drive is different enough. Low end RAID controllers that are found on motherboards tend to be the former, so you ...


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Your root file system is mounted read-only. This likely happened on a reboot. There are a few options: Configure the system to fix errors during reboot. On Ubuntu this is controlled by the FSCKFIX option in the file /etc/default/rcS. Reboot in recovery mode and run fsck -f /dev/disk/by-uuid/e45e30eb-efa4-4cd9-aaf9-c6cbe46aa41c and reboot again. Boot ...


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Physically disconnecting HDD cable and reconnecting it made my HDD visible again. Then I just formatted my SSD and HDD and installed fresh copy of windows into SSD (I'm not going to use Intel RST again).


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Answer to your first question. URE. Unrecoverable Read Error. The disk may be OK, but the data cannot be read preventing rebuild which is the same in the end as a failed disk in terms of a rebuild. I thought the article gave the proper insight on a basic level. Answer to your second question. Same is true for RAID 6 but for larger arrays. I think the ...


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The reason why RAID 5 might not be reliable for large disk sizes is that statistically, storage devices (even when they are working normally) are not immune to errors. This is what is termed UBE (sometimes URE), for Unrecoverable Bit Error rate, and it is quoted in full-sector errors per number of bytes read. For consumer rotational hard disk drives, this ...


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See DISK RAID AND IOPS CALCULATOR and An explanation of IOPS and latency For the calculation of failure RAID, you can use formulas. N is the number of HDD, p - the probability of failure q = (1-p) - reliability. The assumption that the probability of failure of the HDD is equal. For clarity, the probability of failure of different RAID at 5 years of ...


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You mention that the partition is not mounted, but the salient attribute is that the partition is formatted as linux-raid. GParted cannot manipulate a linux-raid partition. See http://gparted.org/features.php


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As mdadm.conf specifies arrays for assembly, it can be used only for "normal" arrays and not legacy ones. The manpage states that for legacy arrays (build mode): This usage is similar to --create. The difference is that it creates an array without a superblock. With these arrays there is no difference between initially creating the array and ...


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Would using ZFS increase performance? Hard to say without knowing your typical disk usage and how you configure your system. For example, how much RAM will you allow ZFS to use? The parity calculations between RAID-Z1 and RAID 5 would probably have similar overheads. Would it be a safer option for my data with equal parity? If you mean a mirror, then ...


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As it is hard to understand exactly what is the cause of your problem, I will take a guess. I guess, you are using GPT partition scheme, as your hard drive is pretty large and it used to be UEFI based. Check this out. And a quote from the link: While GPT support on BIOS systems is theoretically possible it sometimes isn't practical and other times ...


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I realize this question was answered several years ago, but I recently solved a similar problem, and I think I can add some clarity to both the question and Ray M's answer ... A similar two-drive RAID5 running superblock version 1.2 is, like Ray M said, binary identical to RAID1. However, unlike those with v0.9, arrays with 1.x metadata can leave a gap ...


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I had the same issue and after googling a while I didn't find a reliable answer. After giving it some thoughts, I figured that the mirrors have the same data and so we could compare some part of it. NOTE: BE CAREFUL, IF YOU HAVE MORE THAN 2 DRIVES WITH THE SAME CHECKSUM YOU ARE PROBABLY COMPARING EMPTY DISKSPACE, CHOOSE ANOTHER OFFSET (skip option). With ...


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I realize this is an old question, but there's no answer selected and I thought it might help someone else if not the original poster. First, figure out how much space you're going to need on the VMs. If you're coming up short, you may need bigger or more hard drives. I typically will do a raid 1 or raid 10 datastore (using 15k sas drives) on which I ...


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Yes, you can. It's a hybrid configuration similar to RAID 0+1. You can search on the Internet how to set your specific hardware.



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