Seagate ST3000DM001 ext4 formatting

dilbot

If I format a Seagate ST3000DM001 with ext4, it gives 2145430320 K blocks. I'm used to a few % for overhead, but this looks like it's more like 30%. Normally on a 2TB Seagate I get 1949547144 K blocks. There's not much of a benefit in going to 3Tb disks at this rate. Anyone know the reason why this is?

aCOSwt

py-ro · Posted: Mon Dec 03, 2012 10:48 am Post subject:

Please show your partioning.

s4e8 · Apprentice Joined: 29 Jul 2006 Posts: 163

You need EFI GUID partition, the traditional fdisk partition limited to 2T.

dilbot · Posted: Mon Dec 03, 2012 2:12 pm Post subject:

Maybe it is a 64-bit flag I'm missing somewhere, but I don't see any auto_64 switches in the ext4 filesystem or elsewhere in the kernel config tree. Here's the uname, dumpe2fs, df, and fdisk outputs.

j173 linux # uname -a
Linux j173 3.2.12-gentoo #2 SMP Thu Jun 28 18:47:52 PDT 2012 i686 Intel(R) Core(TM)2 Quad CPU Q8300 @ 2.50GHz GenuineIntel GNU/Linux

j173 linux # dumpe2fs -h /dev/sdd1
dumpe2fs 1.42 (29-Nov-2011)
Filesystem volume name: <none>
Last mounted on: /sdd1
Filesystem UUID: d9a3696e-47d1-4048-a764-067d4333380f
Filesystem magic number: 0xEF53
Filesystem revision #: 1 (dynamic)
Filesystem features: has_journal ext_attr resize_inode dir_index filetype needs_recovery extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize
Filesystem flags: signed_directory_hash
Default mount options: user_xattr acl
Filesystem state: clean
Errors behavior: Continue
Filesystem OS type: Linux
Inode count: 134217728
Block count: 536870655
Reserved block count: 26843532
Free blocks: 528396005
Free inodes: 134217717
First block: 0
Block size: 4096
Fragment size: 4096
Reserved GDT blocks: 896
Blocks per group: 32768
Fragments per group: 32768
Inodes per group: 8192
Inode blocks per group: 512
Flex block group size: 16
Filesystem created: Fri Nov 30 04:20:05 2012
Last mount time: Fri Nov 30 04:20:28 2012
Last write time: Fri Nov 30 04:20:28 2012
Mount count: 1
Maximum mount count: -1
Last checked: Fri Nov 30 04:20:05 2012
Check interval: 0 (<none>)
Lifetime writes: 136 MB
Reserved blocks uid: 0 (user root)
Reserved blocks gid: 0 (group root)
First inode: 11
Inode size: 256
Required extra isize: 28
Desired extra isize: 28
Journal inode: 8
Default directory hash: half_md4
Directory Hash Seed: e3d2183e-4e4e-426e-991d-b677359bec8f
Journal backup: inode blocks
Journal features: journal_incompat_revoke
Journal size: 128M
Journal length: 32768
Journal sequence: 0x00007ea3
Journal start: 25977

j173 linux # df -k
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sdd1 2145430320 1892946340 145109852 93% /sdd1

j173 linux # fdisk /dev/sdd
Disk /dev/sdd: 3000.6 GB, 3000592982016 bytes
90 heads, 3 sectors/track, 21705678 cylinders, total 5860533168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x76d4ba03

Device Boot Start End Blocks Id System
/dev/sdd1 2048 4294967294 2147482623+ 83 Linux

dilbot · Posted: Mon Dec 03, 2012 2:33 pm Post subject:

looked at EFI_PARTITION - here's what I have:

Symbol: EFI_PARTITION [=y]
| Type : boolean
| Prompt: EFI GUID Partition support
| Defined at block/partitions/Kconfig:236
| Depends on: BLOCK [=y] && PARTITION_ADVANCED [=y]
| Location:
| -> Enable the block layer (BLOCK [=y])
| -> Partition Types
| -> Advanced partition selection (PARTITION_ADVANCED [=y])
| Selects: CRC32 [=y]

--- Enable the block layer
[*] Support for large (2TB+) block devices and files
[*] Block layer SG support v4
[ ] Block layer SG support v4 helper lib
[ ] Block layer data integrity support
Partition Types --->
IO Schedulers --->

py-ro · Posted: Mon Dec 03, 2012 2:43 pm Post subject:

You got mbr partition Layout, it can't contain Partitions larger then 2TB.

You can do 2 things.

Do 2 Partitions, one a bit over 1TB and the second with the remaining space.

or

Switch to GPT layout.

Bye
Py

aCOSwt · Posted: Mon Dec 03, 2012 2:57 pm Post subject:

Well, so you used fdisk to create the partition ? Correct ?
fdisk cannot create partitions > 2TB (You must have seen a warning displayed when you created it)
Use parted instead.
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Don't try to understand my posts. Immanuel Kant never did, he thinks that only music and laughter do not have to mean anything.

dilbot · Posted: Mon Dec 03, 2012 3:02 pm Post subject:

@ aCOSwt

You're right, there is a warning:

" WARNING: The size of this disk is 3.0 TB (3000592982016 bytes).
DOS partition table format can not be used on drives for volumes
larger than (2199023255040 bytes) for 512-byte sectors. Use parted(1) and GUID
partition table format (GPT)."

But when it started with DOS partition table, I didn't pay any attention to it ;-)

Thanks everyone, I'll switch over to GPT. After so many years using fdisk it'll be a bit of a change for me.

wcg · Guru Joined: 06 Jan 2009 Posts: 551

You may find these documents helpful in switching over:

http://www.rodsbooks.com/gdisk/
http://rodsbooks.com/gdisk/bios.html
http://www.rodsbooks.com/efi-bootloaders/index.html
http://www.rodsbooks.com/bios2uefi/
_________________
TIA