Re: [zfs-discuss] x4500/x4540 does the internal controllers have a bbu?

2010-01-13 Thread Richard Elling
On Jan 12, 2010, at 7:46 PM, Brad wrote: Richard, Yes, write cache is enabled by default, depending on the pool configuration. Is it enabled for a striped (mirrored configuration) zpool? I'm asking because of a concern I've read on this forum about a problem with SSDs (and disks) where

[zfs-discuss] x4500/x4540 does the internal controllers have a bbu?

2010-01-12 Thread Brad
Has anyone worked with a x4500/x4540 and know if the internal raid controllers have a bbu? I'm concern that we won't be able to turn off the write-cache on the internal hds and SSDs to prevent data corruption in case of a power failure. -- This message posted from opensolaris.org

Re: [zfs-discuss] x4500/x4540 does the internal controllers have a bbu?

2010-01-12 Thread Toby Thain
On 12-Jan-10, at 5:53 AM, Brad wrote: Has anyone worked with a x4500/x4540 and know if the internal raid controllers have a bbu? I'm concern that we won't be able to turn off the write-cache on the internal hds and SSDs to prevent data corruption in case of a power failure. A power

Re: [zfs-discuss] x4500/x4540 does the internal controllers have a bbu?

2010-01-12 Thread Richard Elling
On Jan 12, 2010, at 2:53 AM, Brad wrote: Has anyone worked with a x4500/x4540 and know if the internal raid controllers have a bbu? I'm concern that we won't be able to turn off the write-cache on the internal hds and SSDs to prevent data corruption in case of a power failure. Yes,

Re: [zfs-discuss] x4500/x4540 does the internal controllers have a bbu?

2010-01-12 Thread Brad
(Caching isn't the problem; ordering is.) Weird I was reading about a problem where using SSDs (intel x25-e) if the power goes out and the data in cache is not flushed, you would have loss of data. Could you elaborate on ordering? -- This message posted from opensolaris.org

Re: [zfs-discuss] x4500/x4540 does the internal controllers have a bbu?

2010-01-12 Thread Brad
Richard, Yes, write cache is enabled by default, depending on the pool configuration. Is it enabled for a striped (mirrored configuration) zpool? I'm asking because of a concern I've read on this forum about a problem with SSDs (and disks) where if a power outage occurs any data in cache would

Re: [zfs-discuss] x4500/x4540 does the internal controllers have a bbu?

2010-01-12 Thread Toby Thain
On 12-Jan-10, at 10:40 PM, Brad wrote: (Caching isn't the problem; ordering is.) Weird I was reading about a problem where using SSDs (intel x25-e) if the power goes out and the data in cache is not flushed, you would have loss of data. Could you elaborate on ordering? ZFS integrity