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I have the server with 4 disks 6TB each. At start disks were configured as RAID 10 and I had 11TB partition with ex4 filesystem on it. I grew up RAID from level 10 to 5 and now it’s 17.9TB. After reconfiguring RAID I used resize2fs for resize partition, but with ext4 32 bit it give me only 16TB available space. How can I use more than 16TB?

This is parted print information:

GNU Parted 3.2

Using /dev/md3

Welcome to GNU Parted! Type 'help' to view a list of commands.

(parted) p

Model: Linux Software RAID Array (md)

Disk /dev/md3: 17.9TB

Sector size (logical/physical): 512B/4096B

Partition Table: loop

Disk Flags:

Number  Start  End     Size    File system  Flags

1      0.00B  17.9TB  17.9TB  ext4

This is available space:

df -h

Filesystem      Size

/dev/md3         16T

Maybe I can create second partition?

Thanks.

Vladimir Sokolov
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  • try to use future auto_64-bit_support = 1 in /etc/mke2fs.conf – c4f4t0r Mar 21 '18 at 08:32
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    Don’t use RAID5. It’s obsolete. – Sven Mar 21 '18 at 08:48
  • I really second what Sven said. Unrecoverable read errors are a matter of statistic. With 100 GB drives, you don't run into this. With today's disks, you're almost guaranteed to have at least one on a full disk read. With RAID5, that means a high probability of failure on rebuild. – Halfgaar Mar 21 '18 at 09:26
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    What Sven says - PLEASE don't use R5, it's staggeringly dangerous, especially with big/slow disks. – Chopper3 Mar 21 '18 at 09:26

1 Answers1

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It is a limitation of x32 ext4. Check this link as a possible workaround. Don't use RAID-5 for spindle drives especially for 6TB drives. Just imagine the time of rebuilding the RAID array in case if your disk will fail and very poor write performance.

Strepsils
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    Unfortunayely I can't convert ext4 to 64 bit, because of server run with Debian Jessie 3.16 kernel. Is it possible to use space another way, like second volume maybe? How can I create a second volume in this situation? – Vladimir Sokolov Mar 21 '18 at 13:46