war story: testing a disk with a large capacity
Currently Best Buy is selling a 14 TB external disk for $250. Sadly, the days of exponential disk growth of capacity and reduction in price are over. So this is a good sale price. <https://forums.redflagdeals.com/seagate-14tb-external-hd-249-99-save-120-2726376/> I want an internal drive but externals are cheaper, so I bought this. I will have to "shuck" it (remove the case). That will void the warranty, so I wish to test it with Smart Mon Tools. After a certain amount of thrashing about, I discover that - a Seagate USB <-> SATA system has/had bugs switching between "UAS" mode and plain old USB Mass Storage mode - UAS mode is faster for disk operations, so the kernel blocks USB Mass Storage mode on Seagate external drives. - SMARTmon Tools needs USB Mass Storage to deal with this drive To get out of this corner, read: <https://www.smartmontools.org/wiki/SAT-with-UAS-Linux> <https://blog.karssen.org/2022/05/19/getting-smart-information-from-a-seagate-expansion-portable-drive/> The key thing is to: - disconnect the drive - add a "quirk" to suppress UAS for this drive: See "Temporary Settings" in the page linked above - connect the drive again. Check if it is USB Mass Storage - do SMARTmon things - disconnect the drive - unquirk NOTE: The quirk setting didn't work for me. The suggestion was: echo "0x0bc2:0x231a:u" > /sys/module/usb_storage/parameters/quirks The first hex number is the disk manufacturer (Seagate is 0bc2) The second identifies the model. In my case, it should be 2038. I got this from a line in dmesg output about the drive: usb 2-2: New USB device found, idVendor=0bc2, idProduct=2038, bcdDevice=18.01
More recently, I bought a Seagate external 20TB drive from Amazon through my Business Prime account. Still $330, but only through Business Prime. Anyway, I wanted to find out what was inside the case. It's easy if you know the non-obvious trick. sudo smartctl -l farm /dev/sdX tells a lot of details. This line tells me the drive inside is an Exos X24: Model Number: ST20000NM002H-3KV133 I'm top-posting my previous message on the subject because it has relevant and painfully discovered lore.
From: D. Hugh Redelmeier <hugh@mimosa.com> To: Toronto Linux Users Group <talk@gtalug.org> Date: Sat, 28 Dec 2024 15:43:39 -0500 (EST) Subject: war story: testing a disk with a large capacity
Currently Best Buy is selling a 14 TB external disk for $250. Sadly, the days of exponential disk growth of capacity and reduction in price are over. So this is a good sale price. <https://forums.redflagdeals.com/seagate-14tb-external-hd-249-99-save-120-2726376/>
I want an internal drive but externals are cheaper, so I bought this. I will have to "shuck" it (remove the case). That will void the warranty, so I wish to test it with Smart Mon Tools.
After a certain amount of thrashing about, I discover that
- a Seagate USB <-> SATA system has/had bugs switching between "UAS" mode and plain old USB Mass Storage mode
- UAS mode is faster for disk operations, so the kernel blocks USB Mass Storage mode on Seagate external drives.
- SMARTmon Tools needs USB Mass Storage to deal with this drive
To get out of this corner, read: <https://www.smartmontools.org/wiki/SAT-with-UAS-Linux> <https://blog.karssen.org/2022/05/19/getting-smart-information-from-a-seagate-expansion-portable-drive/>
The key thing is to:
- disconnect the drive
- add a "quirk" to suppress UAS for this drive: See "Temporary Settings" in the page linked above
- connect the drive again. Check if it is USB Mass Storage
- do SMARTmon things
- disconnect the drive
- unquirk
NOTE:
The quirk setting didn't work for me. The suggestion was: echo "0x0bc2:0x231a:u" > /sys/module/usb_storage/parameters/quirks
The first hex number is the disk manufacturer (Seagate is 0bc2) The second identifies the model. In my case, it should be 2038. I got this from a line in dmesg output about the drive:
usb 2-2: New USB device found, idVendor=0bc2, idProduct=2038, bcdDevice=18.01
D. Hugh Redelmeier via talk wrote on 2025-03-04 17:33:
After a certain amount of thrashing about, I discover that
- a Seagate USB <-> SATA system has/had bugs switching between "UAS" mode and plain old USB Mass Storage mode
- UAS mode is faster for disk operations, so the kernel blocks USB Mass Storage mode on Seagate external drives.
- SMARTmon Tools needs USB Mass Storage to deal with this drive
To get out of this corner, read: <https://www.smartmontools.org/wiki/SAT-with-UAS-Linux> <https://blog.karssen.org/2022/05/19/getting-smart-information-from-a- seagate-expansion-portable-drive/>
The key thing is to:
I don't know if I missed the December message, but there's some good reading in those links (nicely summarized in email). Seems like quite a PITA to get smartmon data on some USB devices. I'm hoping that I can find your post in my archive should the time come I encounter this issue first-hand. Like the war stories, thanks for writing 'em up.
participants (2)
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D. Hugh Redelmeier -
Ron