* array size
@ 2005-12-13 16:01 Sharif Islam
2005-12-13 16:15 ` Ming Zhang
0 siblings, 1 reply; 7+ messages in thread
From: Sharif Islam @ 2005-12-13 16:01 UTC (permalink / raw)
To: linux-raid
Shouldn't the size of the array be around 760GB? It says spare device 0.
/dev/md0:
Version : 00.90.01
Creation Time : Mon Dec 12 15:56:58 2005
Raid Level : raid5
Array Size : 586075008 (558.92 GiB 600.14 GB)
Device Size : 195358336 (186.31 GiB 200.05 GB)
Raid Devices : 4
Total Devices : 4
Preferred Minor : 0
Persistence : Superblock is persistent
Update Time : Tue Dec 13 09:59:54 2005
State : clean
Active Devices : 4
Working Devices : 4
Failed Devices : 0
Spare Devices : 0
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: array size
2005-12-13 16:01 array size Sharif Islam
@ 2005-12-13 16:15 ` Ming Zhang
2005-12-13 17:09 ` Mark Overmeer
0 siblings, 1 reply; 7+ messages in thread
From: Ming Zhang @ 2005-12-13 16:15 UTC (permalink / raw)
To: Sharif Islam; +Cc: linux-raid
4 disks, 0 spare, so 3x capacity
586075008 = 3 x 195358336
ming
On Tue, 2005-12-13 at 10:01 -0600, Sharif Islam wrote:
> Shouldn't the size of the array be around 760GB? It says spare device 0.
>
> /dev/md0:
> Version : 00.90.01
> Creation Time : Mon Dec 12 15:56:58 2005
> Raid Level : raid5
> Array Size : 586075008 (558.92 GiB 600.14 GB)
> Device Size : 195358336 (186.31 GiB 200.05 GB)
> Raid Devices : 4
> Total Devices : 4
> Preferred Minor : 0
> Persistence : Superblock is persistent
>
> Update Time : Tue Dec 13 09:59:54 2005
> State : clean
> Active Devices : 4
> Working Devices : 4
> Failed Devices : 0
> Spare Devices : 0
>
>
>
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: array size
2005-12-13 16:15 ` Ming Zhang
@ 2005-12-13 17:09 ` Mark Overmeer
2005-12-14 5:54 ` Guy
0 siblings, 1 reply; 7+ messages in thread
From: Mark Overmeer @ 2005-12-13 17:09 UTC (permalink / raw)
To: Ming Zhang; +Cc: Sharif Islam, linux-raid
* Ming Zhang (mingz@ele.uri.edu) [051213 16:15]:
> 4 disks, 0 spare, so 3x capacity
> 586075008 = 3 x 195358336
>
> On Tue, 2005-12-13 at 10:01 -0600, Sharif Islam wrote:
> > Shouldn't the size of the array be around 760GB? It says spare device 0.
> > /dev/md0:
> > Version : 00.90.01
> > Creation Time : Mon Dec 12 15:56:58 2005
> > Raid Level : raid5
> > Array Size : 586075008 (558.92 GiB 600.14 GB)
> > Device Size : 195358336 (186.31 GiB 200.05 GB)
The description of the field is a little confusing. It should read
"Netto Array Size" or "Available Disk Space" or some. Then it is clear
that the last disk is excluded from the shown size.
--
Regards,
MarkOv
------------------------------------------------------------------------
Mark Overmeer MSc MARKOV Solutions
Mark@Overmeer.net solutions@overmeer.net
http://Mark.Overmeer.net http://solutions.overmeer.net
^ permalink raw reply [flat|nested] 7+ messages in thread* RE: array size
2005-12-13 17:09 ` Mark Overmeer
@ 2005-12-14 5:54 ` Guy
0 siblings, 0 replies; 7+ messages in thread
From: Guy @ 2005-12-14 5:54 UTC (permalink / raw)
To: 'Mark Overmeer', 'Ming Zhang'
Cc: 'Sharif Islam', linux-raid
The last disk is not excluded, since the excluded space is used for parity
(xor).
An equal part of all disks is excluded (the parity data).
However, the size is the same as 1 disk being excluded. :)
> -----Original Message-----
> From: linux-raid-owner@vger.kernel.org [mailto:linux-raid-
> owner@vger.kernel.org] On Behalf Of Mark Overmeer
> Sent: Tuesday, December 13, 2005 12:10 PM
> To: Ming Zhang
> Cc: Sharif Islam; linux-raid@vger.kernel.org
> Subject: Re: array size
>
> * Ming Zhang (mingz@ele.uri.edu) [051213 16:15]:
> > 4 disks, 0 spare, so 3x capacity
> > 586075008 = 3 x 195358336
> >
> > On Tue, 2005-12-13 at 10:01 -0600, Sharif Islam wrote:
> > > Shouldn't the size of the array be around 760GB? It says spare device
> 0.
>
> > > /dev/md0:
> > > Version : 00.90.01
> > > Creation Time : Mon Dec 12 15:56:58 2005
> > > Raid Level : raid5
> > > Array Size : 586075008 (558.92 GiB 600.14 GB)
> > > Device Size : 195358336 (186.31 GiB 200.05 GB)
>
> The description of the field is a little confusing. It should read
> "Netto Array Size" or "Available Disk Space" or some. Then it is clear
> that the last disk is excluded from the shown size.
> --
> Regards,
>
> MarkOv
>
> ------------------------------------------------------------------------
> Mark Overmeer MSc MARKOV Solutions
> Mark@Overmeer.net solutions@overmeer.net
> http://Mark.Overmeer.net http://solutions.overmeer.net
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 7+ messages in thread
* Array Size
@ 2004-01-12 3:48 Sharif Islam
2004-01-12 4:19 ` Guy
2004-01-12 5:17 ` jlewis
0 siblings, 2 replies; 7+ messages in thread
From: Sharif Islam @ 2004-01-12 3:48 UTC (permalink / raw)
To: linux-raid
I have 6 IDE hard drives, each 120 GB.
I am bit confused by the reported array size.
# mdadm -D /dev/md0
/dev/md0:
Version : 00.90.00
Creation Time : Fri Jan 9 13:52:20 2004
Raid Level : linear
Array Size : 703324416 (670.74 GiB 720.25 GB)
[....]
# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/hda1 26G 1.2G 23G 5% /
/dev/hda5 2.6G 33M 2.4G 2% /tmp
/dev/hda3 3.9G 59M 3.6G 2% /var
/dev/md0 661G 33M 627G 1% /ppa
Shouldn't the above be ~720GB?
Thanks.
-Sharif
^ permalink raw reply [flat|nested] 7+ messages in thread* RE: Array Size
2004-01-12 3:48 Array Size Sharif Islam
@ 2004-01-12 4:19 ` Guy
2004-01-12 5:17 ` jlewis
1 sibling, 0 replies; 7+ messages in thread
From: Guy @ 2004-01-12 4:19 UTC (permalink / raw)
To: 'Sharif Islam', linux-raid
Overhead!
If filesystem is ext3:
Reserved for root user, default 5%
Inodes
Journal
Superblocks
I don't know the exact numbers.
Why RAID0? You lose a disk and game over!
-----Original Message-----
From: linux-raid-owner@vger.kernel.org
[mailto:linux-raid-owner@vger.kernel.org] On Behalf Of Sharif Islam
Sent: Sunday, January 11, 2004 10:49 PM
To: linux-raid@vger.kernel.org
Subject: Array Size
I have 6 IDE hard drives, each 120 GB.
I am bit confused by the reported array size.
# mdadm -D /dev/md0
/dev/md0:
Version : 00.90.00
Creation Time : Fri Jan 9 13:52:20 2004
Raid Level : linear
Array Size : 703324416 (670.74 GiB 720.25 GB)
[....]
# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/hda1 26G 1.2G 23G 5% /
/dev/hda5 2.6G 33M 2.4G 2% /tmp
/dev/hda3 3.9G 59M 3.6G 2% /var
/dev/md0 661G 33M 627G 1% /ppa
Shouldn't the above be ~720GB?
Thanks.
-Sharif
-
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: Array Size
2004-01-12 3:48 Array Size Sharif Islam
2004-01-12 4:19 ` Guy
@ 2004-01-12 5:17 ` jlewis
1 sibling, 0 replies; 7+ messages in thread
From: jlewis @ 2004-01-12 5:17 UTC (permalink / raw)
To: Sharif Islam; +Cc: linux-raid
On Sun, 11 Jan 2004, Sharif Islam wrote:
> I have 6 IDE hard drives, each 120 GB.
> I am bit confused by the reported array size.
>
> # mdadm -D /dev/md0
> /dev/md0:
> Version : 00.90.00
> Creation Time : Fri Jan 9 13:52:20 2004
> Raid Level : linear
> Array Size : 703324416 (670.74 GiB 720.25 GB)
> /dev/md0 661G 33M 627G 1% /ppa
>
>
> Shouldn't the above be ~720GB?
It is. That 720GB is in units of 1000's, while the 670 GiB is in units of
1024's. As drives get bigger, the difference in manufacturer advertised
sizes (measured in 1000s) is getting more noticable when compared to GB
measured in 1024s. So, the above is telling you your 720GB is really
670GiB, and I'm guessing you formatted it ext3 and the journal is taking
~32mb. That 627+33 = 660G...and you probably have 10G in reserved blocks.
----------------------------------------------------------------------
Jon Lewis *jlewis@lewis.org*| I route
Senior Network Engineer | therefore you are
Atlantic Net |
_________ http://www.lewis.org/~jlewis/pgp for PGP public key_________
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2005-12-14 5:54 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2005-12-13 16:01 array size Sharif Islam
2005-12-13 16:15 ` Ming Zhang
2005-12-13 17:09 ` Mark Overmeer
2005-12-14 5:54 ` Guy
-- strict thread matches above, loose matches on Subject: below --
2004-01-12 3:48 Array Size Sharif Islam
2004-01-12 4:19 ` Guy
2004-01-12 5:17 ` jlewis
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).