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seen Mar 23 at 21:51

Dec
31
awarded  Scholar
Dec
31
accepted Reasonable size for “filesystem reserved blocks” for non-OS disks?
Dec
31
asked Reasonable size for “filesystem reserved blocks” for non-OS disks?
Dec
30
revised Improving mdadm RAID-6 write speed
added 7 characters in body
Dec
30
awarded  Commentator
Dec
30
comment How do you limit root partition disk access to allow drive to go into standby mode?
Parts of it is well described at lesswatts.org/tips/disks.php , see under headings "Use the '-' option in /etc/syslog.conf" and "hal cdrom polling"
Dec
30
comment Improving mdadm RAID-6 write speed
And for backups - I actually do have 4TB backups as a home user :) Spread over multiple external disks, a small NAS and the remaining computers in the house, but I have it. Not that the data are critical, but it took months to rip all my DVDs, and I'd rather not have to do it all over again :)
Dec
30
comment Improving mdadm RAID-6 write speed
Your original numbers aren't that far off what I would expect. With (almost) the same disks as you, I get 60MB/s write and 138 MB/s read in RAID 5. 3x90 MB/s writes is unrealistic (to the best of my knowledge), there's quite a bit overhead to software RAID writing.
Dec
30
awarded  Editor
Dec
30
revised Improving mdadm RAID-6 write speed
partial rewrite, cleanup
Dec
30
comment Improving mdadm RAID-6 write speed
I hope you have a data backup? When experimenting like this you may well end up having to rebuild the raid from scratch. Especially when tweaking stripe sizes and similar, it takes a complete rebuild to see the effect.
Dec
29
comment Improving mdadm RAID-6 write speed
BTW: Do you have AHCI enabled? Which file system - ext3, ext4?
Dec
29
comment Improving mdadm RAID-6 write speed
Try some other values, see what happens. Not an expert on this, but I have WD Greens (4x1.5TB) in md RAID 5 with the same issue - rather slow write speed. My system is down at the moment, but I'll experiment at my end as well, and update here if I manage to improve it.
Dec
29
answered Improving mdadm RAID-6 write speed
Dec
28
awarded  Teacher
Dec
28
answered How do you limit root partition disk access to allow drive to go into standby mode?
Dec
27
comment Recommended storage scheme for home server? (LVM/JBOD/RAID 5…)
BTW, there is also Greyhole, which manages a pool of drives somewhat like Windows Home Server.
Dec
27
comment Recommended storage scheme for home server? (LVM/JBOD/RAID 5…)
Could be interesting in a few years :) Looking for a stable, low-hassle system myself - otherwise I'd probably go with btrfs - but looks interesting, and could perhaps be relevant for the more experimental?
Dec
26
comment Recommended storage scheme for home server? (LVM/JBOD/RAID 5…)
It's true that just the RAID partitions need to be the same size, but not sure what to do with the remaining space. Ex. three disks 1.0TB, 1.5TB and 2.0TB could be RAID 5 using 3x1.0TB partitions, but that would leave 1.5TB unused space. I could stuff all of it into LVM (so the LVM runs on one RAID and two non-RAID volumes), but I can't immediately see that "partial RAID" has any advantages. Agree that RAID 5/6 (using similar-sized disks) + LVM may be the best option for a resilient single system. I like the LVM flexibility and snapshotting, so I'm leaning towards LVM. Thanks for input!
Dec
26
comment Recommended storage scheme for home server? (LVM/JBOD/RAID 5…)
I'll try there if I don't get a response here. But setting up a home server with a few extra disks is becoming relatively mainstream, and a far cry from managing enterprise servers, so I believe the question more naturally belongs here. Plus the next person considering an Ubuntu-based home server is more likely to check this site for answers.