Mailinglist Archive: opensuse (1077 mails)
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[opensuse] Re: http://download.opensuse.org/ unresponsive
- From: Linda Walsh <suse@xxxxxxxxx>
- Date: Thu, 03 May 2012 05:20:59 -0700
- Message-id: <4FA2782B.30805@tlinx.org>
Dave Howorth wrote:
------
I disagree.
1) RAID is no substitute for regular backups.
2) RAID 6 even in hardware created a noticeable penalty, while
RAID5 gets close to RAID0 speeds on READS and most WRITES.
IF you have enough disks to do RAID 10, then you probably have enough
to do 1 RAID5 and a another RAID5 dedicated to backup storage. Using tower of
hanoi rotation one can minimize space for daily backups while requiring at most 4-5 restores from separate sources to bring up to the latest day (usually 2-3).
FWIW, I use a RAID-50 3RAID5's (4data+3par) in a RAID0 + 1 spare. I figure statistically a RAID5 with 4 data discs is about the limit of safety for RAID5, but with 2-3TB /HD ..
I very much sympathize with SUSE... been there, had this happen --
and I was the one who killed the 2nd disk (on trying to replace the faulty one,
of course counted from wrong direction...me<==*bang*)
-- all downloaded/internet content. 5-6T...*ouch*
Only 1 6T volume with downloaded material wasn't regularly backed up (don't have the space for more than a duplicate and that's tight). Rest of
system is backed up with dump/restore (xfs). But starting out, it was just
downloaded stuff...thought I could always D/l it again...but at some point...
*ouch*... it got past a size I wanted to D/l again.
I learned...fortunately it was d/l'able stuff, so most was recoverable
and my system disk and main server shares for serving local material to my PC(s)
is fully backed up.
The backups are on a separate set of disks...though sharing same enclosure...(ouch)...
Anyway, bad things happen once in a while...I still don't think
RAID6 is worth the overhead for as often as this type of thing happens.
If you were a bank? Yeah..sure... but Open suse doesn't need 5-9's of uptime
(99.999%) -- that's a reason for mirrors...
(FWIW, I don't know of anyone who keeps regular backups like me...I'm
a bit paranoid)...few companies do either I would note -- unless they have dedicated IT departments...which I doubt Opensuse has given they are an open
source company -- they really have alot of dedicated IT staff in my limited
experience. ;-(....).
Condolences...
--
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To contact the owner, e-mail: opensuse+owner@xxxxxxxxxxxx
Per Jessen wrote:
Even with hot spares, the array will be running degraded until it's
fully synced. With terabyte size disks, a resync can take quite a while
= window for disaster if a 2nd disk break.
Right. RAID 5 is not a good idea with big disks. RAID 6 is better if the
hardware is capable of it. Otherwise mdadm RAID 10 seems like a good
compromise.
------
I disagree.
1) RAID is no substitute for regular backups.
2) RAID 6 even in hardware created a noticeable penalty, while
RAID5 gets close to RAID0 speeds on READS and most WRITES.
IF you have enough disks to do RAID 10, then you probably have enough
to do 1 RAID5 and a another RAID5 dedicated to backup storage. Using tower of
hanoi rotation one can minimize space for daily backups while requiring at most 4-5 restores from separate sources to bring up to the latest day (usually 2-3).
FWIW, I use a RAID-50 3RAID5's (4data+3par) in a RAID0 + 1 spare. I figure statistically a RAID5 with 4 data discs is about the limit of safety for RAID5, but with 2-3TB /HD ..
I very much sympathize with SUSE... been there, had this happen --
and I was the one who killed the 2nd disk (on trying to replace the faulty one,
of course counted from wrong direction...me<==*bang*)
-- all downloaded/internet content. 5-6T...*ouch*
Only 1 6T volume with downloaded material wasn't regularly backed up (don't have the space for more than a duplicate and that's tight). Rest of
system is backed up with dump/restore (xfs). But starting out, it was just
downloaded stuff...thought I could always D/l it again...but at some point...
*ouch*... it got past a size I wanted to D/l again.
I learned...fortunately it was d/l'able stuff, so most was recoverable
and my system disk and main server shares for serving local material to my PC(s)
is fully backed up.
The backups are on a separate set of disks...though sharing same enclosure...(ouch)...
Anyway, bad things happen once in a while...I still don't think
RAID6 is worth the overhead for as often as this type of thing happens.
If you were a bank? Yeah..sure... but Open suse doesn't need 5-9's of uptime
(99.999%) -- that's a reason for mirrors...
(FWIW, I don't know of anyone who keeps regular backups like me...I'm
a bit paranoid)...few companies do either I would note -- unless they have dedicated IT departments...which I doubt Opensuse has given they are an open
source company -- they really have alot of dedicated IT staff in my limited
experience. ;-(....).
Condolences...
--
To unsubscribe, e-mail: opensuse+unsubscribe@xxxxxxxxxxxx
To contact the owner, e-mail: opensuse+owner@xxxxxxxxxxxx
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