# Tmp2 Usage Rules ## 前言 目前本系十餘部工作站個別主機 (ws\*, meow\*) 的 /tmp2 暫存空間在 0.5-12TB 之間不等(詳細容量請見工作站硬體資料,或者使用 `df` 等指令察看),不過經常有使用者投訴 /tmp2 空間不敷使用,主要原因是有人暫時或累積佔用了大量的空間。

經助教群與負責老師討論後,我們將限制 /tmp2 的個人空間使用量,當個別主機或所有主機總合的 /tmp2 空間小於安全下限時,或個別空間超量使用時,系統會限制其寫入權限,甚至在預警五日後自動刪除部份被警告的檔案,以保障多數使用者權益。

217工作站主要是支援大多數使用者的一般需求,請大家空間用完儘早刪除,個人有長期大量硬碟空間使用需求的,請尋求相關教授實驗室支援。詳細的 /tmp2 使用規則訂定如下: ## rule 1 各工作站之 /tmp2 提供暫存資料作不特定用途,位於各工作站之 local 端。使用者將資料放置於 /tmp2 存取速度較 NFS (Network File System) 快,也可舒緩 NFS 的負載。唯 /tmp2 不提供作為大量資料備份用途,因採用 RAID 0 配置,故也不保證資料之完整,請自行備份。除此之外,工作站將會不定期清理 /tmp2,會清除硬碟中所有資料,工作站管理團隊不負備份責任;清理前會寄信通知,請務必注意。 ## rule 2 當某工作站的 /tmp2 剩餘空間比例小於 1/(4n+2) 時,不滿足例外情況的前 n 名 /tmp2 用量的使用者將無法在該工作站上寫入 (read-only)。 例外情況為以下兩點: 1. 使用者的 /tmp2 用量小於剩餘空間 2. 使用者的 /tmp2 用量小於該工作站 /tmp2 總量的 1% ## rule 3 當某工作站的 /tmp2 剩餘空間比例小於 5% 時,工作站組可以寄信通知使用者於五日內清除部分資料。五日後,工作站組將視情況移動部分過度佔用資料(見第4條)並恢復所限制的寫入權限。 ## rule 4 在第 3 條中,若使用者們未於五日內清出足夠空間,工作站組會將部分大檔案與長久閒置檔案移置其他硬碟空間並通知使用者。若使用者需要拿回被刪除的資料,請於收信時間起三日內聯絡工作站助教 (217ta@csie.ntu.edu.tw) ,並自行準備儲存裝置複製資料,逾時則無法取回資料。 ## rule 5 例外:對於有課程需求 (如 DSA、SP) 的課程助教或老師,若有收到警告信件,或是寫入權限被封鎖,請來信向工作站助教 (217ta@csie.ntu.edu.tw) 說明需要多少空間及資料放置時間,以免造成課程上的不便。 以上五點規則是為了保障諸多數使用者的使用權利,謝謝大家的體諒與配合。 217助教團隊敬上 The workstation have received complaints from users that there’s no enough storage on /tmp2. Currently the sizes of /tmp2 on workstation servers range from 0.5 to 5.4 TB, and the shortage is arisen from the large-size and long-term data on /tmp2. As a result, for the sake of public interest, workstation will start restricting the usage of /tmp2. If the remaining storage of individual/all servers is below safety lower bound or there is excess usage on individual users, these users’ data will be moved from /tmp2. For users who have demand on large or long-term storage, you should store your data on individual device. The following is the usage rules: 1. /tmp2 is a local partition on workstation servers (ws\*) with faster access time than network file system(NFS). However, /tmp2 is used for storage of temporary data, and it does not guarantee the reliability of data because of RAID 0 configuration, thus users should not treat /tmp2 as a backup partition. Also notice that we'll clean /tmp2 partition from time to time; we'll send mail to inform the users.

2. When the remaining usage of /tmp2 on any server is below 1/(4n+2), workstation will restrict write permission for users with the top n usage on that server. The exceptions are as follows: * The user's /tmp2 usage is below the remaining space. * The user's /tmp2 usage is below 1% of the /tmp2 capacity of that workstation.

3. When the remaining usage of /tmp2 on any server is below 5%, workstation will send mail to restricted users. These users should remove their data in 5 days, otherwise workstation will move their data from /tmp2(see rule 4) and restore their permission.

4. In rule 3, if users don’t clean enough space on /tmp2, the server will move their data to other disk. If users want to take their data back, they should send mail to TAs(217ta@csie.ntu.edu.tw) in 3 days and prepare external storage device, otherwise they will lose their data.

5. Exception: Teachers or TAs that need to put long-term, large-size course material on /tmp2 should send mail to TAs(217ta@csie.ntu.edu.tw) to specify how much storage and how much time they need to store their data. We hope these rules can benefit users with demand on temporary storage for any purpose, thanks for your cooperation. Best regards, 217 TAs