Dean S. Messing wrote:
Bill Davidsen wrote:
: Dean S. Messing wrote:
: > Again, I don't get these speeds. Seq. reads are about
: > 170% of the average of my three physical drives if I turn up
: > the look-ahead. Then random access reads drops to slightly less
: > than my slowest drive.
: >
:
Bill Davidsen wrote:
: Dean S. Messing wrote:
: > Again, I don't get these speeds. Seq. reads are about
: > 170% of the average of my three physical drives if I turn up
: > the look-ahead. Then random access reads drops to slightly less
: > than my slowest drive.
: >
: As nearly as I can tell,
: Dean S. Messing wrote:
: > I have also discovered "smartctl" and have read that if the short smartctl
: > tests are run daily and the long test weekly that the chances of being
: > caught "with my pants down" are quite low, even in a two disk RAID-0
: > config. What is your opinion?
: >
:
:
Michal Soltys writes:
: Dean S. Messing wrote:
: >
: > I don't see how one would do incrementals. My backup system uses
: > currently does a monthly full backup, a weekly level 3 (which
: > saves everything that has changed since the last level 3 a week ago) and
: > daily level 5's (wh
Dean S. Messing wrote:
Again, I don't get these speeds. Seq. reads are about
170% of the average of my three physical drives if I turn up
the look-ahead. Then random access reads drops to slightly less
than my slowest drive.
As nearly as I can tell, Dean was talking about RAID-10 at that poin
Dean S. Messing wrote:
I have also discovered "smartctl" and have read that if the short smartctl
tests are run daily and the long test weekly that the chances of being
caught "with my pants down" are quite low, even in a two disk RAID-0
config. What is your opinion?
There's a good paper on
Dean S. Messing wrote:
I don't see how one would do incrementals. My backup system uses
currently does a monthly full backup, a weekly level 3 (which
saves everything that has changed since the last level 3 a week ago) and
daily level 5's (which save everything that changed today).
Rsync
> Goswin von Brederlow writes:
: > Dean Mesing writes:
: > If I'm using an ext3 filesystem (which I plan to do) would Full and
: > Incremental dumps to a cheap 'n big USB drive (using the dump/restore
: > suite) not work?
:
: Probably. But why not rsync? It will copy all changes and the data on
"Dean S. Messing" <[EMAIL PROTECTED]> writes:
> Goswin von Brederlow writes:
> : Dean Mesing writes:
> : > Goswin von Brederlow writes:
> : > : LVM is not the same as LVM. What I mean is that you still have choices
> : > : left.
> : >
> : > Sorry, Goswin. Even though you gave your meaning, I stil
Goswin von Brederlow writes:
: Dean Mesing writes:
: > Goswin von Brederlow writes:
: > : LVM is not the same as LVM. What I mean is that you still have choices
: > : left.
: >
: > Sorry, Goswin. Even though you gave your meaning, I still don't
: > understand you here. (I must be dense this morn
"Dean S. Messing" <[EMAIL PROTECTED]> writes:
> Goswin von Brederlow writes:
> : Dean S. Messing writes:
> : > Michael Tokarev writes:
> : > : Dean S. Messing wrote:
> : > : []
> : > : > [] That's what
> : > : > attracted me to RAID 0 --- which seems to have no downside EXCEPT
> : > : > safety :
Goswin von Brederlow writes:
: Dean S. Messing writes:
: > Michael Tokarev writes:
: > : Dean S. Messing wrote:
: > : []
: > : > [] That's what
: > : > attracted me to RAID 0 --- which seems to have no downside EXCEPT
: > : > safety :-).
: > : >
: > : > So I'm not sure I'll ever figure out "the
"Dean S. Messing" <[EMAIL PROTECTED]> writes:
> Michael Tokarev writes:
> : Dean S. Messing wrote:
> : []
> : > [] That's what
> : > attracted me to RAID 0 --- which seems to have no downside EXCEPT
> : > safety :-).
> : >
> : > So I'm not sure I'll ever figure out "the right" tuning. I'm at th
This is to both Bill Davidsen and Michael Tokarev.
I just realised in re-reading previous messages that I badly screwed
up my attributions in my just-sent message. I attributed to Bill some
technical remarks by Michael.
I apologise to both of you!
Dean
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Bill Davidsen wrote:
Dean Messing wrote:
: > I understand I only get the speed of a single drive was I was not
: > aware of the safety factor. I had intended to use snapshotting off
: > to a cheap USB drive each evening. Will that not keep me safe within a
: > day's worth of data change? I on
Dean S. Messing wrote:
Michael Tokarev writes:
: Dean S. Messing wrote:
: []
: > [] That's what
: > attracted me to RAID 0 --- which seems to have no downside EXCEPT
: > safety :-).
: >
: > So I'm not sure I'll ever figure out "the right" tuning. I'm at the
: > point of abandoning RAID entire
Michael Tokarev writes:
: Dean S. Messing wrote:
: []
: > [] That's what
: > attracted me to RAID 0 --- which seems to have no downside EXCEPT
: > safety :-).
: >
: > So I'm not sure I'll ever figure out "the right" tuning. I'm at the
: > point of abandoning RAID entirely and just putting the t
Dean S. Messing wrote:
[]
> [] That's what
> attracted me to RAID 0 --- which seems to have no downside EXCEPT
> safety :-).
>
> So I'm not sure I'll ever figure out "the right" tuning. I'm at the
> point of abandoning RAID entirely and just putting the three disks
> together as a big LV and bei
Michal Soltys writes:
: Dean S. Messing wrote:
: >
: > Also (as I asked) what is the downside? From what I have read, random
: > access reads will take a hit. Is this correct?
: >
: > Thanks very much for your help!
: >
: > Dean
: >
:
: Besides bonnie++ you should probably check iozone. It
Bill Davidsen wrote:
: Dean S. Messing wrote:
>
snip
: Do you want to tune it to work well now or work well in the final
: configuration? There is no magic tuning which is best for every use, if
: there was it would be locked in and you couldn't change it.
I want it to work well in the fin
Dean S. Messing wrote:
Also (as I asked) what is the downside? From what I have read, random
access reads will take a hit. Is this correct?
Thanks very much for your help!
Dean
Besides bonnie++ you should probably check iozone. It will allow you to test
very specific settings quite thoro
Dean S. Messing wrote:
Justin Piszcz wrote:
: One of the 5-10 tuning settings:
:
: blockdev --getra /dev/md0
:
: Try setting it to 4096,8192,16384,32768,65536
:
: blockdev --setra 4096 /dev/md0
:
:
I discovered your January correspondence to the list about this. Yes,
the read-ahead length
On Wed, 19 Sep 2007, Dean S. Messing wrote:
Justin Piszcz wrote:
: Dean Messing wrote:
: > Jusin Piszcz wrote:
: > :
: > I discovered your January correspondence to the list about this. Yes,
: > the read-ahead length makes a dramtic difference---for sequential data
: > reading. However, .
Justin Piszcz wrote:
: Dean Messing wrote:
: > Jusin Piszcz wrote:
: > :
: > I discovered your January correspondence to the list about this. Yes,
: > the read-ahead length makes a dramtic difference---for sequential data
: > reading. However, ...
: > : Then re-benchmark.
: >
: > Large Rea
On Wed, 19 Sep 2007, Dean S. Messing wrote:
Justin Piszcz wrote:
: One of the 5-10 tuning settings:
:
: blockdev --getra /dev/md0
:
: Try setting it to 4096,8192,16384,32768,65536
:
: blockdev --setra 4096 /dev/md0
:
:
I discovered your January correspondence to the list about this. Yes,
the
Justin Piszcz wrote:
: One of the 5-10 tuning settings:
:
: blockdev --getra /dev/md0
:
: Try setting it to 4096,8192,16384,32768,65536
:
: blockdev --setra 4096 /dev/md0
:
:
I discovered your January correspondence to the list about this. Yes,
the read-ahead length makes a dramtic difference
One of the 5-10 tuning settings:
blockdev --getra /dev/md0
Try setting it to 4096,8192,16384,32768,65536
blockdev --setra 4096 /dev/md0
Also, with a 3-disk raid5 that is the worst performance you can get using
only 3 disks, while with a 10 disk raid5 it'd be closer to 90%. Reads you
should
Justin Piszcz wrote:
On Tue, 18 Sep 2007, Dean S. Messing wrote:
:
: >
: >
: > I'm not getting nearly the read speed I expected
: > from a newly defined software RAID 5 array
: > across three disk partitions (on the 3 drives,
: > of course!).
: >
: > Would someone kindly point me straight?
: >
:
On Tue, 18 Sep 2007, Dean S. Messing wrote:
I'm not getting nearly the read speed I expected
from a newly defined software RAID 5 array
across three disk partitions (on the 3 drives,
of course!).
Would someone kindly point me straight?
After defining the RAID 5 I did `hdparm -t /dev/md0'
a
I'm not getting nearly the read speed I expected
from a newly defined software RAID 5 array
across three disk partitions (on the 3 drives,
of course!).
Would someone kindly point me straight?
After defining the RAID 5 I did `hdparm -t /dev/md0'
and got the abysmal read speed of ~65MB/sec.
The i
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