[opensuse] setting up a server with raid
Hello, I'm pretty new to raid, read the raid wiki but not sure to understand all. I have (at least for some time) to use already in stock consumer disks, but the server will not be stressed, only serves web pages and occasionally photo/video files. I build it myself because I will have fiber link at home at mid january. I plan to use three disks: two as raid 1 mirror, and the third as spare. Is it better to have a three disks mirror? I don't get precisely how a spare is advertised to the raid. The three disks are very different (1Tb 2.5", 1.5Tb 3.5" and 2Tb 3.5") - of course I will use the same 1Tb space for raid on each disk Two disks will be internal, the third will be on external esata dock the server will have up to date rsync backups. I have to boot on these disks. I plan to make 4 GPT partitions: * swap * UEFI * GRUB * linux 1) may I do two linux partitions for system and /home - data? Isn't that making the use of raid more difficult (two raids array), or may be it's in fact simpler? 2) I have a disk replicator (Aukey dock), so I plan to partition one drive and replicate to the two others with the dock. Is it a good idea or is it overkill? (I can also partition by hand with yast) 3) the raid wiki speaks about bitmap and advantages to have it, what to do with yast? others ideas welcome thanks jdd -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
jdd wrote:
Hello,
I'm pretty new to raid, read the raid wiki but not sure to understand all. I have (at least for some time) to use already in stock consumer disks, but the server will not be stressed, only serves web pages and occasionally photo/video files. I build it myself because I will have fiber link at home at mid january.
I plan to use three disks: two as raid 1 mirror, and the third as spare. Is it better to have a three disks mirror? I don't get precisely how a spare is advertised to the raid.
A spare disk is added to the array, it is just marked as spare.
The three disks are very different (1Tb 2.5", 1.5Tb 3.5" and 2Tb 3.5") - of course I will use the same 1Tb space for raid on each disk
Two disks will be internal, the third will be on external esata dock
the server will have up to date rsync backups.
I have to boot on these disks.
I plan to make 4 GPT partitions:
* swap * UEFI * GRUB * linux
1) may I do two linux partitions for system and /home - data? Isn't that making the use of raid more difficult (two raids array), or may be it's in fact simpler?
That's a matter of taste. I have a number of external servers with 2 SATA drives in each. They have two partitions - swap and linux. Those are then RAID'ed to md0 and md1.
2) I have a disk replicator (Aukey dock), so I plan to partition one drive and replicate to the two others with the dock. Is it a good idea or is it overkill? (I can also partition by hand with yast)
I don't see what the replication adds to the game. Just use YaST to install on your RAID array(s). -- Per Jessen, Zürich (1.2°C) http://www.cloudsuisse.com/ - your owncloud, hosted in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
Le 20/12/2016 à 11:10, Per Jessen a écrit :
jdd wrote:
A spare disk is added to the array, it is just marked as spare.
but is something written to it or only in case of an other disk failure? that's to see what is different with three disk raid 1
1) may I do two linux partitions for system and /home - data? Isn't that making the use of raid more difficult (two raids array), or may be it's in fact simpler?
That's a matter of taste. I have a number of external servers with 2 SATA drives in each. They have two partitions - swap and linux. Those are then RAID'ed to md0 and md1.
swap is on raid? why?
2) I have a disk replicator (Aukey dock), so I plan to partition one drive and replicate to the two others with the dock. Is it a good idea or is it overkill? (I can also partition by hand with yast)
I don't see what the replication adds to the game. Just use YaST to install on your RAID array(s).
raid wiki insists to have identical disks thanks jdd -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On Tue, Dec 20, 2016 at 1:14 PM, jdd
Le 20/12/2016 à 11:10, Per Jessen a écrit :
jdd wrote:
A spare disk is added to the array, it is just marked as spare.
but is something written to it or only in case of an other disk failure? that's to see what is different with three disk raid 1
1) may I do two linux partitions for system and /home - data? Isn't that making the use of raid more difficult (two raids array), or may be it's in fact simpler?
That's a matter of taste. I have a number of external servers with 2 SATA drives in each. They have two partitions - swap and linux. Those are then RAID'ed to md0 and md1.
You can also in principle partition MD itself or setup LVM on top.
swap is on raid? why?
Because RAID is about availability and non-stop operation and if your application is (partially) swapped out and swap disk fails your application fails too.
2) I have a disk replicator (Aukey dock), so I plan to partition one drive and replicate to the two others with the dock. Is it a good idea or is it overkill? (I can also partition by hand with yast)
I don't see what the replication adds to the game. Just use YaST to install on your RAID array(s).
raid wiki insists to have identical disks
They mean really identical hardware (at least with very close specifications), not bit clone of content. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
jdd wrote:
Le 20/12/2016 à 11:10, Per Jessen a écrit :
jdd wrote:
A spare disk is added to the array, it is just marked as spare.
but is something written to it or only in case of an other disk failure? that's to see what is different with three disk raid 1
The spare is hot-added when another drive fails, that's all. Until that happens, it is not touched.
1) may I do two linux partitions for system and /home - data? Isn't that making the use of raid more difficult (two raids array), or may be it's in fact simpler?
That's a matter of taste. I have a number of external servers with 2 SATA drives in each. They have two partitions - swap and linux. Those are then RAID'ed to md0 and md1.
swap is on raid? why?
Availability, the whole reason you want RAID. If a swap-partition that is in use fails, your system won't survive.
2) I have a disk replicator (Aukey dock), so I plan to partition one drive and replicate to the two others with the dock. Is it a good idea or is it overkill? (I can also partition by hand with yast)
I don't see what the replication adds to the game. Just use YaST to install on your RAID array(s).
raid wiki insists to have identical disks
Okay, I'm not sure what that means. If you create two 10Gb partitions on completely different disks, in complete different areas, you can still combine them into a RAID1 array. I've never used a disk replication in my life :-) -- Per Jessen, Zürich (1.7°C) http://www.cloudsuisse.com/ - your owncloud, hosted in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
Le 20/12/2016 à 12:43, Per Jessen a écrit :
Okay, I'm not sure what that means. If you create two 10Gb partitions on completely different disks, in complete different areas, you can still combine them into a RAID1 array. I've never used a disk replication in my life :-)
https://raid.wiki.kernel.org/index.php/Setting_up_a_(new)_system#Setting_up_... not sure of what that mind (grub) jdd -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
jdd wrote:
Le 20/12/2016 à 12:43, Per Jessen a écrit :
Okay, I'm not sure what that means. If you create two 10Gb partitions on completely different disks, in complete different areas, you can still combine them into a RAID1 array. I've never used a disk replication in my life :-)
https://raid.wiki.kernel.org/index.php/Setting_up_a_(new)_system#Setting_up_...
not sure of what that mind (grub)
There is no mention of identical disks in that. -- Per Jessen, Zürich (1.6°C) http://www.cloudsuisse.com/ - your owncloud, hosted in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
participants (3)
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Andrei Borzenkov
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jdd
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Per Jessen