I have 15x1TB disks, each disk usable space should be
1Tib=1000000000000B=1000000000000/1024/1024/1024G=931G.
As it shows in command format:
# echo | format | grep MD
3. c4t60026B900053AA15000002C74B8F0EADd0
<DELL-MD3000-0735-931.01GB>
4. c4t60026B900053AA15000002C94B8F0EE3d0
<DELL-MD3000-0735-931.01GB>
5. c4t60026B900053AA15000002CB4B8F0F0Dd0
<DELL-MD3000-0735-931.01GB>
6. c4t60026B900053AA15000002CD4B8F0F3Dd0
<DELL-MD3000-0735-931.01GB>
7. c4t60026B900053AA15000002CF4B8F0F6Dd0
<DELL-MD3000-0735-931.01GB>
8. c4t60026B900053AA15000002D14B8F0F9Cd0
<DELL-MD3000-0735-931.01GB>
9. c4t60026B900053AA15000002D34B8F0FC8d0
<DELL-MD3000-0735-931.01GB>
10. c4t60026B900053AA18000002A04B8F0D91d0
<DELL-MD3000-0735-931.01GB>
11. c4t60026B900053AA18000002A24B8F0DC5d0
<DELL-MD3000-0735-931.01GB>
12. c4t60026B900053AA18000002A44B8F0DEDd0
<DELL-MD3000-0735-931.01GB>
13. c4t60026B900053AA180000029C4B8F0D35d0
<DELL-MD3000-0735-931.01GB>
14. c4t60026B900053AA180000029E4B8F0D61d0
<DELL-MD3000-0735-931.01GB>
15. c4t60026B900053AA180000036E4DBF6BA6d0
<DELL-MD3000-0735-931.01GB>
16. c4t60026B900053AA18000002984B8F0CD2d0
<DELL-MD3000-0735-931.01GB>
17. c4t60026B900053AA15000003074B901CF3d0
<DELL-MD3000-0735-931.01GB>
#
I create 2 raidz1(7 disk) and 1 global hot spare as zpool:
NAME STATE READ
WRITE CKSUM
datapool ONLINE 0
0 0
raidz1 ONLINE 0
0 0
c4t60026B900053AA15000002C74B8F0EADd0 ONLINE 0
0 0
c4t60026B900053AA15000002C94B8F0EE3d0 ONLINE 0
0 0
c4t60026B900053AA15000002CB4B8F0F0Dd0 ONLINE 0
0 0
c4t60026B900053AA15000002CD4B8F0F3Dd0 ONLINE 0
0 0
c4t60026B900053AA15000002CF4B8F0F6Dd0 ONLINE 0
0 0
c4t60026B900053AA15000002D14B8F0F9Cd0 ONLINE 0
0 0
c4t60026B900053AA15000002D34B8F0FC8d0 ONLINE 0
0 0
raidz1 ONLINE 0
0 0
spare ONLINE 0
0 7
c4t60026B900053AA18000002A04B8F0D91d0 ONLINE 10
0 0 194K resilvered
c4t60026B900053AA180000036E4DBF6BA6d0 ONLINE 0
0 0 531G resilvered
c4t60026B900053AA18000002A24B8F0DC5d0 ONLINE 0
0 0
c4t60026B900053AA18000002A44B8F0DEDd0 ONLINE 0
0 0
c4t60026B900053AA15000003074B901CF3d0 ONLINE 0
0 0
c4t60026B900053AA180000029C4B8F0D35d0 ONLINE 0
0 0
c4t60026B900053AA180000029E4B8F0D61d0 ONLINE 0
0 0
c4t60026B900053AA18000002984B8F0CD2d0 ONLINE 0
0 0
spares
c4t60026B900053AA180000036E4DBF6BA6d0 INUSE
currently in use
I expect to have 14*931/1024=12.7TB zpool space, but actually, it only
have 12.6TB zpool space:
# zpool list
NAME SIZE USED AVAIL CAP HEALTH ALTROOT
datapool 12.6T 9.96T 2.66T 78% ONLINE -
#
And I expect the zfs usable space is 12*931/1024=10.91TB, but actually,
it only have 10.58TB zfs space.
Can any one explain where the disk space goes?
Regards,
Ding
On Tue, Jun 14, 2011 at 10:09 PM, Ding Honghui <ding_honghui at vobile.cn> wrote:> I expect to have 14*931/1024=12.7TB zpool space, but actually, it only have > 12.6TB zpool space: > # zpool list > NAME ? ? ? SIZE ? USED ?AVAIL ? ?CAP ?HEALTH ?ALTROOT > datapool ?12.6T ?9.96T ?2.66T ? ?78% ?ONLINE ?- > # > > And I expect the zfs usable space is 12*931/1024=10.91TB, but actually, it > only have 10.58TB zfs space. > > Can any one explain where the disk space goes?I generally like to start with the number of guaranteed sectors on a drive rather than worrying about converting "vendor math". :) Then I do $NSEC/2097152 to get GB (assuming 512-byte sectors). ZFS reserves 1/64 of the pool size to protect copy-on-write as the pool approaches being full. After you make your usable space calculation, subtract 1/64 of that (total*.016) and that should be very close to the available space reported by ''zfs list''. Eric