Good evening everyone! Guys, about the P420 RAID controller, I have a question about the operation mode: What would be better: HBA or RAID-0 with BBU (active write cache)? Thanks in advance!
Are you baiting me? ;) HBA. Always. RAID HBAs are the devil.
On Apr 19, 2023, at 12:56 AM, Murilo Morais <murilo@evocorp.com.br> wrote:
Good evening everyone!
Guys, about the P420 RAID controller, I have a question about the operation mode: What would be better: HBA or RAID-0 with BBU (active write cache)?
Thanks in advance! _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io
Den ons 19 apr. 2023 kl 00:55 skrev Murilo Morais <murilo@evocorp.com.br>:
Good evening everyone! Guys, about the P420 RAID controller, I have a question about the operation mode: What would be better: HBA or RAID-0 with BBU (active write cache)?
As already said, always give ceph (and zfs and btrfs..) the raw disks to handle for itself, instead of doing hardware striping/raiding and so on. There are multiple reasons for this, including weird/bad firmware and (for raid0) loss of redundancy and so on, but there are also corner cases where you may need/want to move disks from one box to another. If you use "raw" disks, then what is on the platters most often is 1:1 to what the computer sees, and hence if you move the drive over to another box, it will not matter if it has a HBA or Raid card, what brand of disk controller it is and so on. The new server will also see 1:1 of the data the former machine wrote and this is what you want. If you have a raid0/jbod/raid1/raidX setup on a particular raid controller card with a particular firmware version, you may not be able to move your complete raid set over to a newer box. Perhaps the raid card model is no longer available, perhaps the raid firmware logic is new and different on how to stripe data or place sectors on the raid members. Perhaps it detects disks in the wrong order or something. It is very possible that you have zero problems with raid setups, but the extra complexities when moving raid sets from one generation of computer/controller to another makes the risk of some kind of portability issue non-zero. Old grumpy storage admins don't like non-zero risks if we actually can avoid it. -- May the most significant bit of your life be positive.
I want add one thing to what other says, we discussed this between Cephalocon sessions, avoid HP controllers p210/420, or upgrade firmware to latest. These controllers has strange bug, during high workload they restart itself. BR, Sebastian
On 19 Apr 2023, at 08:39, Janne Johansson <icepic.dz@gmail.com> wrote:
Den ons 19 apr. 2023 kl 00:55 skrev Murilo Morais <murilo@evocorp.com.br>:
Good evening everyone! Guys, about the P420 RAID controller, I have a question about the operation mode: What would be better: HBA or RAID-0 with BBU (active write cache)?
As already said, always give ceph (and zfs and btrfs..) the raw disks to handle for itself, instead of doing hardware striping/raiding and so on.
There are multiple reasons for this, including weird/bad firmware and (for raid0) loss of redundancy and so on, but there are also corner cases where you may need/want to move disks from one box to another. If you use "raw" disks, then what is on the platters most often is 1:1 to what the computer sees, and hence if you move the drive over to another box, it will not matter if it has a HBA or Raid card, what brand of disk controller it is and so on. The new server will also see 1:1 of the data the former machine wrote and this is what you want.
If you have a raid0/jbod/raid1/raidX setup on a particular raid controller card with a particular firmware version, you may not be able to move your complete raid set over to a newer box. Perhaps the raid card model is no longer available, perhaps the raid firmware logic is new and different on how to stripe data or place sectors on the raid members. Perhaps it detects disks in the wrong order or something.
It is very possible that you have zero problems with raid setups, but the extra complexities when moving raid sets from one generation of computer/controller to another makes the risk of some kind of portability issue non-zero. Old grumpy storage admins don't like non-zero risks if we actually can avoid it.
-- May the most significant bit of your life be positive. _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io
LSI 9266/9271 as well in an affected range unless ECO’d
On Apr 19, 2023, at 3:13 PM, Sebastian <sebcio.t@gazeta.pl> wrote:
I want add one thing to what other says, we discussed this between Cephalocon sessions, avoid HP controllers p210/420, or upgrade firmware to latest. These controllers has strange bug, during high workload they restart itself.
BR, Sebastian
On 19 Apr 2023, at 08:39, Janne Johansson <icepic.dz@gmail.com> wrote:
Den ons 19 apr. 2023 kl 00:55 skrev Murilo Morais <murilo@evocorp.com.br>:
Good evening everyone! Guys, about the P420 RAID controller, I have a question about the operation mode: What would be better: HBA or RAID-0 with BBU (active write cache)?
As already said, always give ceph (and zfs and btrfs..) the raw disks to handle for itself, instead of doing hardware striping/raiding and so on.
There are multiple reasons for this, including weird/bad firmware and (for raid0) loss of redundancy and so on, but there are also corner cases where you may need/want to move disks from one box to another. If you use "raw" disks, then what is on the platters most often is 1:1 to what the computer sees, and hence if you move the drive over to another box, it will not matter if it has a HBA or Raid card, what brand of disk controller it is and so on. The new server will also see 1:1 of the data the former machine wrote and this is what you want.
If you have a raid0/jbod/raid1/raidX setup on a particular raid controller card with a particular firmware version, you may not be able to move your complete raid set over to a newer box. Perhaps the raid card model is no longer available, perhaps the raid firmware logic is new and different on how to stripe data or place sectors on the raid members. Perhaps it detects disks in the wrong order or something.
It is very possible that you have zero problems with raid setups, but the extra complexities when moving raid sets from one generation of computer/controller to another makes the risk of some kind of portability issue non-zero. Old grumpy storage admins don't like non-zero risks if we actually can avoid it.
-- May the most significant bit of your life be positive. _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io
ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io
participants (5)
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Anthony D'Atri
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Anthony D'Atri
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Janne Johansson
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Murilo Morais
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Sebastian