RT-AC87U, Merlin's Firmware, & a 5TB HDD

[infamous_pb]

Hello all! I'm looking into upgrading my RT-N66U to a RT-AC87U. I currently am using a 2TB USB HDD attached to it. I got a good deal on a Seagate Expansion 5TB USB 3.0 (from Gamestop with all my in-store credit) and wanted to make sure that this USB HDD would be compatible. From Asus's website (http://event.asus.com/2009/networks/disksupport/), it shows that it only allows for up to 4TB. Does anyone know if anything higher than 4TB would work on the RT-AC87U? Perhaps Merlin's Firmware allows higher TB HDDs to work? Any help would be greatly appreciated.

 

[vanic]

I think it's kernel issue.

 

[RMerlin]

Only way to be sure is for someone to actually test it. Sadly, manufacturers like Seagate never test their products on routers (even rarely do so under Linux), so there's no clear rule as to what works and what doesn't.

When dealing with such large amounts of data however, I feel that having a NAS is more likely to be reliable. There are even some high capacity disks that can directly be connected to your network these days, saving the cost of a dedicated NAS.

 

[Jerry12]

From Asus's website (http://event.asus.com/2009/networks/disksupport/), it shows that it only allows for up to 4TB.

That page sats the router supports up to 4 TB partitions in ext3 and other formats. So you could use, say, GParted to partition your 5 TB drive into 2 or more partitions.

(Posts like this thread lead me to stick with ext3 over ext4.)

 

[sfx2000]

Well - ext4 is fairly mature these days, and I would recommend it when possible...

Cribbed from another site - but captures things succinctly...

Ext2

• Ext2 stands for second extended file system.
• It was introduced in 1993. Developed by Rémy Card.
• This was developed to overcome the limitation of the original ext file system.
• Ext2 does not have journaling feature.
• On flash drives, usb drives, ext2 is recommended, as it doesn’t need to do the over head of journaling.
• Maximum individual file size can be from 16 GB to 2 TB
• Overall ext2 file system size can be from 2 TB to 32 TB

Ext3

• Ext3 stands for third extended file system.
• It was introduced in 2001. Developed by Stephen Tweedie.
• Starting from Linux Kernel 2.4.15 ext3 was available.
• The main benefit of ext3 is that it allows journaling.
• Journaling has a dedicated area in the file system, where all the changes are tracked. When the system crashes, the possibility of file system corruption is less because of journaling.
• Maximum individual file size can be from 16 GB to 2 TB
• Overall ext3 file system size can be from 2 TB to 32 TB
• There are three types of journaling available in ext3 file system.
  • Journal – Metadata and content are saved in the journal.
  • Ordered – Only metadata is saved in the journal. Metadata are journaled only after writing the content to disk. This is the default.
  • Writeback – Only metadata is saved in the journal. Metadata might be journaled either before or after the content is written to the disk.
• You can convert a ext2 file system to ext3 file system directly (without backup/restore).

Ext4

• Ext4 stands for fourth extended file system.
• It was introduced in 2008.
• Starting from Linux Kernel 2.6.19 ext4 was available.
• Supports huge individual file size and overall file system size.
• Maximum individual file size can be from 16 GB to 16 TB
• Overall maximum ext4 file system size is 1 EB (exabyte). 1 EB = 1024 PB (petabyte). 1 PB = 1024 TB (terabyte).
• Directory can contain a maximum of 64,000 subdirectories (as opposed to 32,000 in ext3)
• You can also mount an existing ext3 fs as ext4 fs (without having to upgrade it).
• Several other new features are introduced in ext4: multiblock allocation, delayed allocation, journal checksum. fast fsck, etc. All you need to know is that these new features have improved the performance and reliability of the filesystem when compared to ext3.
• In ext4, you also have the option of turning the journaling feature “off”.

 

[Jerry12]

Nice, sfx2000. That's helpful!

Let's also clarify that "TB" above (also on the RedHat and ASUS pages) is really TiB, Tebibyte, 2^40 bytes.
GParted distinguishes TB from TiB, so e.g. if you create a 2 TB partition, it'll be 1.8 TiB.

Disk drives are conventionally sized in decimal units like TB.

 

[ajb999]

I have a 3TB backup+ and a 5TB expansion drive connected to my ac87u. It is running stock firmware and both drives are Seagate. No problems at all.

Edit: The 5TB drive is one partition.

 

[infamous_pb]

Thanks everyone. Just to be on the safe side, I'll just look for a 4TB (I'm currently looking at a WD Elements 4TB USB 3.0). I know its always been recommended to have it formatted in one of the Ext formats, but I have to have it NTFS (I need it easily accessible from various Windows 7 machines without installing additional software on each one...). Thanks ya'll

 

[Jerry12]

CMIIW, NTFS format will only help when you connect the drive directly to a Windows machine.

 

[jb510]

I have a 3TB backup+ and a 5TB expansion drive connected to my ac87u. It is running stock firmware and both drives are Seagate. No problems at all.

Edit: The 5TB drive is one partition.

How is the 5TB drive formated? NTFS or EXT4?