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Note: Please make sure you also check out KnownProblems. If you are here because you cannot get your drive or flash device to format in the first place, first check KnownProblems and also consider trying the workaround documented in the FailedFormatFix wiki page.

Can't access your NSLU2 anymore? Hard drive not detected in the web interface? Then this is the place to be.

Step-by-step procedure

1. Shut NSLU2 down.

2. Switch USB-HDD off or disconnect it.

3. Turn NSLU2 on.

4. Enable Telnet (e.g. via

5. Telnet into NSLU2 with root/uNSLUng login/password.

6. Reconnect your USB-HDD, and switch it on. Note: you are now "hot plugging" your disk, which works for many NSLU2's and hard disks, but not all.

7. Type 'sh' (not necessary, just more comfortable)

8. Type 'mount -t ext3 /dev/sda1 /mnt/tmpmnt'.

  • If there is no error message, proceed to the next step.
  • If you get the error message, mount: Mounting /dev/sda1 on /mnt/tmpmnt failed: No such device or address, then see the section =Hot plugging fails= section below.

9. Type 'ls /mnt/tmpmnt'. So now you (hopefully) see your data.

10. Type 'df' is there sda1?

  • If yes, then
  • If no, then we have a problem. As of November 2007, there is no solution here. At least you can backup your data by copying it from from /mnt/tmpmnt.

Hot plugging fails

If your disk doesn't mount at all, check the =Individual stories= below for hints about what has worked for other people.

  • Several people report success in getting the NSLU2 to recognise the disk when they format it in NTFS using a Windows machine, then try it again with the NSLU2. Of course, this erases all existing data on the disk.

If your disk mounts when it's powered on while the NSLU2 is still booting, but doesn't mount when "hot-plugged" after the NSLU2 is fully started, here are some ideas:

  • If you are attempting to install unslung firmware, and are at the step where you are starting up the NSLU2 with no disk in order to have a known root password, then powering up the disk in order to run /bin/unsling, then consider accessing the disk using Linux or Windows, editing the /passwd file in the conf partition, and replace the encrypted password for root with that of some other user's entry. This means that you can start up the disk at the same time as the NSLU2, and the root password will now be the same as that user's password, and you can log in from telnet.
  • Sometimes problems like this seem to be cable or timing problems. In that case, replacing the USB cable, or adding a USB extension cable, may help.

Individual stories

First things first: If you have a Freecom drive it will not work reliably. See here and here. I tried one Sept 2007 and this is still the case. Maybe things will change with R75.

I solved the problem after reading the other posts and following the "3-step solution". I hope the following guide is a helpful summary of many of the posts and should solve the problem for anyone willing to wipe the drive they are unslinging to:

(NOTE: You will need to backup and wipe/format the drive you are unslinging to)

1. Plug the USB-Drive to Windows and quickformat it using the NTFS file system (Control Panel/Administrative Tools/Disk Management).

2. Turn on NSLU2 and follow the initial unling directions, i.e.:enable telnet; log on using hyper terminal;

3. Plug in USB-HDD to the NSLU2 again - the NTFS drive should now be hot-pluggable

4. Do a HDD format on the disk using the webinterface ( - the drive should now be readable as EXT3.

5. Complete the unslinging process

6. The latest version of Unslung will prompt you to change the password so that in the future you will be able to telnet in without unplugging all the drives at startup.

Please note that if you later upload an old configuration file you will no longer be able to telnet in anymore as the password will have changed again. The obvious solution to this is to manually configure your device after you have unslung and then presumably you will be able to save and use a new configuration file.

Alternatively you could upload the old configuration file and see below for manual ways of changing the password: ChangePasswordsFromTheCommandLine.

7. Restart your slug and it should boot unslung with telnet access possible using your new password!

I would agree with the post further down the page - I couldn't get my slug to detect the HD after telneting in. I tried formatting it to FAT32? and NTFS to try and get it to detect, but to no avail.

However, with the HD quick formatted to NTFS with a Windows machine, I plugged it in first, fired up the slug and telneted in, which i was able to do because there was no password stored on the HD due to formatting.

The HD was therefore detected, I formatted to ext3 with the web interface, and was able then to unsling successfully.

I know this goes against everything in the readme about not having the HD plugged in when you telnet, but it seems to have worked well.

I had problems with getting my slug to recognize a disk when it was inserted after boot (to unsling to). If I booted with the disk inserted it showed up and could be formatted, but not if it was inserted after boot. After much tinkering to and fro, the problem finally went away after a re-flash of the same firmware.

I'm having a similar problem as the previous author (yes having followed above advice) - I can't get the disk recognised if I hot plug it in (Lacie BD). Is there a list anywhere of disk that are compatible with unslinging? This is very frustrating being able to telnet in and _almost_ be able to unsling but then not being able to see the HD. Any ideas anyone?

Same problem here with my Freecom USB 2.0 drive. Been tinkering with this for many days now, but still same problem. For me the solution is simple, skip using the NSLU all together since i have 1 NSLU and 18 Freecom Disks. This is a original firmware problem and Linksys offers no solution whatsoever. I managed however to find out from Linksys that the problem was with External drives having power save functions enabled as default. Well my NSLU companion was not a companion to keep, gonna go for another solution as this takes to much time compared to what i hoped to get from it.

Same problem as post 2 with a brandless USB 2.0 drive I picked up in Malaysia. Upon removing the PCB from the external drive, I found


printed on the controller chip. A database could be created* so users hoping to use an external housing with their NSLU could look up the controller chip and stay away from the potentially problematic models or conversely, models that work. Until the kinks have been smoothened out over at Linksys with currently un-hot-pluggable chips, I hope someone would upload a Norton Ghost(or similar disk imaging software) image of a freshly unslung disk as a stop-gap measure for those of us who're stuck. Thanks. Also, I note that this problem posted in the last 3 posts seem to get the expected result when following the steps in the original post. Just that the drive doesn't appear in the web interface and /sbin/unsling disk1/2 gives the following: "Error: /share/hdd/data is not a mounted disk" or "Error: /share/flash/data is not a mounted disk"


Just got a break by intentionally pre-formatting the harddisk with NTFS, plug into NSLU before booting, telnetting in and then only after that formatting the disk in the web interface and then running unsling after that.

My Harddisk wasn't detected also. Here is a 3-step solution:
1. Plug the USB-Drive to an Windows 2k/XP and format it with NTFS (like the one above).
2. Plug the USB-HDD to the NSLU2 again
3. Do a HDD format in the webinterface (
4. Let's go for unsling

Had the same problems as above, using a Maxstore OneTouch. It would get detected by the slug if it was connected at power up. It would not when I was telneting in to unsling the firmware. I could mount it using the instructions above, it just wasn't being automatically mounted

By having the drive turned off and then turning the drive on I got it to work fine. The other times the drive had been on and I was just plugging the USB cable into the unit.

* There is an usb enclosure compatibility database here: http://groups.yahoo.com/group/nslu2-general/database. You have to be a member of the nslu2-general group, though.

Big problems with Gericom Multifunction Storage (contains a SAMSUNG HA250JC HD and CF/MD/SD/SM/MS/MMC card reader along with a double USB 2.0 hub): no matter if I formatted the HD with ext3, FAT or NTFS, I could not get my Slug flashed with Unslug 5.5 beta to recognize it. Had to revert to Linksys V2.3R63 firmware, since V2.3R29 wouldn't do it either. I wonder if OpenSlug would be a better choice for this beast..

Had the same problems as described in the first entry.
I wanted to use disk1 to unsling. Disk1 was already formatted by the NSLU, but not recognized if plugged in after NSLU boot.
Firmware: V2.3R63. uNSLUng 6.8 beta.

The way I was able to unsling:
1)boot without disk
2)telnet to NSLU
3)attach disk (disk is powered off)
4)power on disk
5)type 'mount -t ext3 /dev/sdb1 /mnt/tmpmnt'. => you should see your data there
6)type 'umount /mnt/tmpmnt'
7)type 'mount -t ext3 /dev/sdb1 /share/hdd/data'
8)type 'mount -t ext3 /dev/sdb2 /share/hdd/conf'
9)reload the web-interface => you should see your disk there on port 1
10)proceed to unsling as described in the readme (in my case I had to type '/sbin/unsling disk1')
(replace sdb* with sda* and 'hdd' with 'flash' (e.g. /share/hdd/data becomes /share/flash/data) if you want to use disk2 instead of disk1)

<Just to add a vote of confidence in this solution. I had the same pathology with a Lacie 300GB disk and had tried a series of reflashes and reset of sysconfig all to no avail. The recipie above proved the cure.>

I had exactly the same problem as above, and the solution offered also worked for me, with a usb drive attached to disk 1 port. Thanks, whoever it was. The problem could be something to do with the fact that recent NSLU2s? seem to have the more flexible port (usb flash drives and usb disks) designated as disk 2 and the usb drive only port as disk 1. This is the opposite way round to the configuration stated in the Unslung-6.8-beta-README.txt.

I had a problem with a external box of LaCie (exact model is LaCie d2 Hard Drive Extreme 300Gb). The disk was previously formated by the NSLU, and for the unslinging procedure I was not able to see it. Neither the technique of "mounting" it, nor the change of port solved the problem. I solved my problem by attaching it to my Mac, format it to whatever (in my case HFS), then attach it to the slug before booting, format it via the web interface (only worked on port USB nb 1), log with telnet and finally unslinging.

I was encountering this same problem, but I may have discovered a simpler fix.

Here's what I was seeing: I got to the step in the instructions that say to plug in the drive and wait for it to be mounted. I would do that. Almost immediately, the web interface would tell me that Disk 2 had been recognized. The "Disk" page in the web interface showed that Drive 2 was "Formatted (ext3)", as promised. But if I looked on the "Shares" page, NO shares would be listed. Within telnet, I was able to "ls /share/flash/data", and see all my files with no problems. But when I tried to run unsling, I'd get the countdown followed by the error, "/share/flash/data (disk2, /dev/sda1) is not a mounted disk".

Here's what fixed the problem for me: on the "Disk" page, I clicked the button to start a Scandisk on the disk in question. When it completed, all my shares once again showed up on the "Shares" page, and unsling ran without problems!

So if you have data on your drive and you don't want to use the trick mentioned in a post above (where they format the drive twice, once in NTFS and once with the NSLU2), try running a Scandisk from the web interface. After it completes, try unslinging again.

Someone up above noted that they were able to see their big disk when the booted up their slug with the drive connected, then couldn't see it when they booted without, enabled telnet, and then plugged in the disk. This is the same problem that I was having. I have a WD MyBook Essential Edition 500GB (WDG1U5000). I suspect that this applies for more disks that don't have on/off switches.

My symptoms: After I formatted the drive successfully, when I hot-plugged the drive, it would tell me that the drive is 6 MB and XX% full. I also couldn't view the files on the drive from the web page. It told me "page not found", or something to that effect.

What worked for me: Unplug the power chord to the drive (These things have no on/off switch), boot the slug, enable telnet, telnet in, connect the USB cable, THEN plug the power chord into the drive. I still had the same 6 MB problem manifest. Then I used the mount, unmount, mount /data, mount /conf strategy listed above. When I did this, the size of the drive per the web page was correct, but I still couldn't use the web file browser utility. I WAS, however, able to unsling. Now all is well.

Getting this thing to format was a PITA too... Seems that I had to format using the 6.8-beta firmware, and then run the scandisk to get it to recognize on reboot. My advice is, if you have problems, some combination of the advice listed in this wiki should work for you. Just be ready to exercise patience, and keep trying.

Same problem as the last few people, the following worked for me (from the above instructions):

7)type 'mount -t ext3 /dev/sdb1 /share/hdd/data'

8)type 'mount -t ext3 /dev/sdb2 /share/hdd/conf'

Similar situation: after flashing the firmware and confirming it was running I enabled telnet, logged in, attached the USB drive to Disk 1, and then tried to run "unsling disk1". It showed "Waiting for /share/hdd/data", and counted down from 120, then reported: "Error: /share/hdd/data <disk1, /dev/sdb1> is not a mounted disk". I also noted that on the web interface, it showed my disk as mounted and formated as ext3, but it did not show any of the users I had created under the Linksys firmware.

Using the hints from above, I did

mount -t ext3 /dev/sdb1 /share/hdd/data

mount -t ext3 /dev/sdb2 /share/hdd/conf

This did the trick. Thanks everyone! (I'm adding this note simply to add some of the phrases I searched for in the Wiki but couldn't find - hopefully the next person to encounter this will find the solution quicker than I did!)

I have seriously spent some time on this issue after wanting to add a Seagate FreeAgent 500GB drive to the USB port 1 whilst running Unslung on Disk 2 (250GB Seagate). The 500GB drive was formatted with 1 single large partition EXT3? and was detected by the NSLU2 (/dev/hdd_sdb listed and fdisk -l /dev/sd? showed it there and recognized) but it just did not want to mount at all. I tried so much through web interface, rebooting sequences, resetting, remounting, reformatting the hole shabang over and over again in all shapes and sizes, but no joy. After having tried the hammer method I finally started to think and looked at dmesg on the unslung 6.8b NSLU2. The error I found was: 'EXT3? unsupported inode size 256' or some message to that effect. I checked the existing inode size of the existing 250GB drive to which I was unslung and it said 128 (dumpe2fs -h /dev/sda1|grep Inode).

I hooked up the 500GB drive to my Ubuntu 9.04 machine to reformat (AGAIN!!!) but i.s.o. using gparted I went to the commandline and entered: sudo mke2fs -j -I 128 /dev/sdc.

When finished I hooked the 500GB to the Disk 1 port of the unslung 6.8b NSLU2 again and mounted manually!!! Hey presto... there she was, all 500GB of her... Dunno what's going to happen when I reboot the NSLU2 though. . .;-)) Hopefully the 500GB hdd will be detected but not mounted and won't result in any copying of conf. files ???

I wanted to share this with you, hoping this helps everyone with similar problems with large drives formatted to an inode size of 256 and maybe solve the general issue of large drives and mounting ??

I also ran into this with a Seagate FreeAgent 1TB drive, previously formatted as ext3 and containing some 500GB of data I had hoped to serve via FTP on my NSLU2 running Unslung V2.3R63-uNSLUng-6.10-beta.

  1. dumpe2fs -h /dev/sde1|grep Inode

dumpe2fs 1.41.12 (17-May-2010) Inode count: 61054976 Inodes per group: 8192 Inode blocks per group: 512 Inode size: 256

However, a WD 1GB drive formatted as a single NTFS partition was automatically detected and mounted with no problems.

Page last modified on December 28, 2011, at 10:11 AM